Greater Dublin Drainage Project Irish Water

Environmental Impact Assessment Report: Volume 3 Part A of 6

Chapter 9 Biodiversity (Marine) June 2018

Envir onmental Impact Assessment Report: Vol ume 3 Part A of 6 Irish Water

Environmental Impact Assessment Report: Volume 3 Part A of 6

Contents 9. Biodiversity (Marine) ...... 1 9.1 Introduction ...... 2 9.2 Methodology ...... 4 9.2.1 Desktop Study ...... 4 9.2.2 Field Surveys ...... 4 9.2.3 Underwater Noise Modelling ...... 8 9.2.4 Impact Assessment Methodology ...... 9 9.2.5 Non-Statutory Consultation ...... 13 9.3 Baseline Environment ...... 16 9.3.1 Designated Sites for Nature Conservation ...... 16 9.3.2 Geomorphology and Seabed Sediments ...... 17 9.3.3 Sediment Chemistry ...... 18 9.3.4 Marine Benthos ...... 22 9.3.5 Water Quality Profiling, Sampling and Plankton ...... 32 9.3.6 Baldoyle Estuary Walkover ...... 36 9.3.7 Marine Mammals ...... 39 9.3.8 Fish and Shellfish ...... 45 9.3.9 Summary Evaluation (Importance) of Key Marine Ecological Receptors and Habitats ...... 51 9.4 Impact of the Proposed Project – Construction Phase ...... 53 9.4.1 Construction of the Microtunnelling Compounds Adjacent to the Baldoyle Estuary and Construction Works Upstream of Marine Environment with Potential for Contaminated Runoff ...... 54 9.4.2 Tunnelling Underneath Baldoyle Bay and Tunnelling Compounds ...... 55 9.4.3 Dredging of Proposed Outfall Pipeline Route (Marine Section) ...... 63 9.4.4 Piling for Tunnel Interface and/or Fibre Optic Cable ...... 69 9.4.5 Installation of the Proposed Marine Diffuser ...... 70 9.5 Impact of the Proposed Project – Operational Phase ...... 72 9.6 ‘Do Nothing’ Impact ...... 78 9.7 Mitigation Measures ...... 78 9.7.1 Construction Phase ...... 78 9.7.2 Operational Phase ...... 82 9.8 Residual Impacts ...... 82 9.9 References ...... 83

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9. Biodiversity (Marine)

This Chapter of the Environmental Impact Assessment provides a characterisation of the receiving environment and an assessment of the impacts of the Proposed Project on estuarine, coastal and marine ecology. The key areas of the Proposed Project boundary which may be particularly sensitive are Baldoyle Bay and Rockabill to Dalkey Island Special Areas of Conservation (SAC). In particular, the sub-littoral reefs close to the proposed outfall pipeline route (marine section) and the presence of designated marine mammals in the waters surrounding the outer end were of concern and have received a significant level of assessment. A large number of estuarine and marine surveys were undertaken between 2012 and 2017. This included a walkover survey over the mudflats, Salicornia and Atlantic salt meadows of the Baldoyle Bay Estuary SAC beneath which the proposed outfall route (marine section) will pass using micro tunnelling. The potential for impact in this area relates to bentonite or air breakout during construction along with possible contamination from runoff from the proposed temporary construction compounds. These possible impacts can be mitigated through a Construction Environmental Management Plan, preventing discharges to the estuary and detailed control of bentonite flow and air pressures where needed.

The proposed outfall pipeline route (marine section) area was surveyed using multiple geophysical and benthic surveys between 2012 and 2017. Benthic data shows a diverse population based on sands to the west and mixed sandy gravels to the east at shelf break with no contaminants found in surface or dredge sediment depths. These habitats are not particularly sensitive to construction impacts and no significant impact is predicted.

The proposed marine diffuser will be located within Rockabill to Dalkey Island SAC (designated for Reefs at Ireland’s Eye and the harbour porpoise over the greater area). The reefs were assessed in 2015 using camera and divers and these showed a diverse habitat with a naturally high silt content. The Construction Phase presents a minor risk of plume effects during dredging whilst near the proposed marine diffuser location during spring tides, but no mitigation other than monitoring and control of dredging operations is needed to keep this to a negligible impact on this feature.

Harbour porpoises were assessed by an extensive monitoring survey between 2015 and 2017 using both acoustic and observational techniques in the vicinity of the Proposed Project. Results showed some of the highest densities recorded in Ireland and moderate levels of activity throughout the year with numbers increasing in late summer. This was coincident with the presence of calves and may be due to seasonally abundant food sources such as sprat, herring and Trisopterus and gadoid species. Numbers then reduced during late spring/early summer which may be associated with an offshore movement of this species before calving. No impacts are expected for dredging operations outside the SAC, but passive acoustic monitoring and marine mammal observations will be carried out to limit proximity during high noise construction operations (i.e. piling). Operations will also be restricted to outside peak population periods to reduce a potential minor impact to a negligible impact within the SAC.

Fish surveys showed mostly nursery areas of limited importance but with a few sensitive/important fish species were present. The shellfish fishery is also important commercially but not sensitive ecologically. No impact from construction other than restriction of fishing grounds and loss of habitat at the proposed marine diffuser location are predicted.

No operational impacts of the Proposed Project and no predicted significant residual effects upon estuarine, coastal and marine ecological receptors are predicted.

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9.1 Introduction This Chapter of the Environmental Impact Assessment Report (EIAR) provides a characterisation of the receiving environment and an assessment of the ecological impacts of the Greater Dublin Drainage Project (hereafter referred to as the Proposed Project) on marine ecology. The marine ecology impact assessment addresses the potential impacts on the benthos (animals living on or within the seafloor), marine mammals, fish, plankton and water quality. This assessment is based on the Proposed Project description set out in Chapter 4 Description of the Proposed Project in Volume 2 Part A of this EIAR (and allied construction plans appended to that Chapter), and supported as necessary by other specialist assessments of the EIAR, including inter alia, Chapter 8 Marine Water Quality, Chapter 10 Biodiversity (Marine Ornithology) and Chapter 11 Biodiversity (Terrestrial and Freshwater Aquatic) in Volume 3 Part A of this EIAR. The Proposed Project will form a significant component of a wider strategy to meet future wastewater treatment requirements within the Greater Dublin Area as identified in a number of national, regional and local planning policy documents. The plant, equipment, buildings and systems associated with the Proposed Project will be designed, equipped, operated and maintained in such a manner to ensure a high level of energy performance and energy efficiency. The table below includes a summary of the Proposed Project elements. A full description of the Proposed Project is detailed within Volume 2 Part A, Chapter 4 Description of the Proposed Project in Volume 2 Part A of this EIAR. Please also refer to Figure 4.1 Proposed Project Overview in Volume 5 Part A of this EIAR.

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Proposed Project Outline Description of Proposed Project Element Element

Proposed • WwTP to be located on a 29.8 hectare (ha) site in the townland of Clonshagh (Clonshaugh) in Fingal. • 500,000 population equivalent wastewater treatment capacity. Wastewater • Maximum building height of 18m. Treatment Plant • Sludge Hub Centre to be co-located on the same site as the WwTP with a sludge handling and (WwTP) treatment capacity of 18,500 tonnes of dry solids per annum. • SHC will provide sustainable treatment of municipal wastewater sludge and domestic septic tank sludges generated in Fingal to produce a biosolid end-product. • Biogas produced during the sludge treatment process will be utilised as an energy source. • Access road from the R139 Road, approximately 400m to the southern boundary of the site. • Egress road, approximately 230m from the western boundary of the site, to Clonshaugh Road. • A proposed temporary construction compound to be located within the site boundary. Proposed • Abbotstown pumping station to be located on a 0.4ha site in the grounds of the National Sports Campus at Abbotstown. Abbotstown pumping • Abbotstown pumping station will consist of a single 2-storey building with a ground level floor area of station 305m2 and maximum height of 10m and a below ground basement 17m in depth with floor area of 524m2 incorporating the wet/dry wells. • The plan area of the above ground structure will be 305m2 and this will have a maximum height of 10m. • A proposed temporary construction compound to be located adjacent to the Abbotstown pumping station site. Proposed orbital • The orbital sewer route will intercept an existing sewer at Blanchardstown and will divert it from this point to the WwTP at Clonshagh. sewer route • Constructed within the boundary of a temporary construction corridor. • 13.7km in length; 5.2km of a 1.4m diameter rising main and 8.5km of a 1.8m diameter gravity sewer. • Manholes/service shafts/vents along the route. • Odour Control Unit at the rising main/gravity sewer interface. • Proposed temporary construction compounds at Abbotstown, Cappoge, east of Silloge, Dardistown and west of Collinstown Cross to be located within the proposed construction corridor. Proposed North • The NFS will be intercepted in the vicinity of the junction of the access road to the WwTP with the R139 Road in lands within the administrative area of Dublin City Council. Fringe Sewer (NFS) • NFS diversion sewer will divert flows in the NFS upstream of the point of interception to the WwTP. diversion sewer • 600m in length and 1.5m in diameter. • Operate as a gravity sewer between the point of interception and the WwTP site. Proposed outfall • Outfall pipeline route (land based section) will commence from the northern boundary of the WwTP and will run to the R106 Coast Road. pipeline route (land • 5.4km in length and 1.8m in diameter. based section) • Pressurised gravity sewer. • Manholes/service shafts/vents along the route. • Proposed temporary construction compounds (east of R107 Malahide Road and east of Saintdoolaghs) located within the proposed construction corridor. Proposed outfall • Outfall pipeline route (marine section) will commence at the R106 Coast Road and will terminate at a discharge location approximately 1km north-east of Ireland’s Eye. pipeline route • 5.9km in length and 2m in diameter. (marine section) • Pressurised gravity tunnel/subsea (dredged) pipeline. • Multiport marine diffuser to be located on the final section. • Proposed temporary construction compounds (west and east of Baldoyle Bay) to be located within the proposed construction corridor. Proposed Regional • Located on an 11ha site at Newtown, Dublin 11. • Maximum building height of 15m. Biosolids Storage • Further details and full impact assessment are provided in Volume 4 Part A of this EIAR. Facility (RBSF)

The total Construction Phase will be approximately 48 months, including a 12 month commissioning period to the Operational Phase. The Proposed Project will serve the projected wastewater treatment requirements of existing and future drainage catchments in the north and north-west of the Dublin agglomeration, up to the Proposed Project’s 2050 design horizon. Please note that there is no biodiversity (marine) assessment of the proposed Regional Biosolids Storage Facility, as the site is located inland. This Chapter should be read with the following figures presented in Volume 5 Part A and appendices presented in Volume 3 Part B of this EIAR:

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• Volume 5, Figure 9.1 Summary of Field Survey Operations for the Proposed Outfall Pipeline Route (Marine Section); • Volume 5, Figure 9.2 Summary of Bathymetry Data for the Proposed Outfall Pipeline Route (Marine Section); • Volume 5, Figure 9.3 Sediment Changes near the Proposed Outfall Pipeline Route (Marine Section) and Diffuser; • Volume 5, Figure 9.4 Casual Sightings and Dedicated Surveys of the Harbour Porpoise; • Volume 5, Figure 9.5 Inshore Shellfish Grounds along the Fingal Coast; • Volume 5, Figure 9.6 Combined Suspended Sediment Concentrations Arising from Dredging Operations Over the Duration of the Dredging Works for the Proposed Outfall Pipeline Route (Marine Section); • Volume 3 Part B, Appendix A9.1 Marine Ecology; • Volume 3 Part B, Appendix A9.2 Marine Mammal Survey Investigation; and • Volume 3 Part B, Appendix A9.3 Underwater Noise Assessment and Modelling.

9.2 Methodology

9.2.1 Desktop Study Key literature sources used to identify features of marine ecological value within the study area and surrounding region were as follows:

• Coastal Habitats: Ecological Study of the Coastal Habitats in County Fingal Phase IV: Intertidal Habitats (Ecoserve 2005) and a Saltmarsh Monitoring Survey conducted in Baldoyle Estuary between 2006 and 2008 (McCorry and Ryle 2009); • Fishing Ground and Fish Species: Fisheries Study of Fingal Coastal Zone (Ecoserve 2006), Ecological Study of the Coastal Habitats in County Fingal Phase III – Estuarine Fish (Central Fisheries Board 2004) and Commercial Fishing Assessment (Brown and May Marine Ltd 2008) along with information provided in submissions and by Inland Fisheries Ireland (IFI); • Marine Ecology: Intertidal and Subtidal Benthic Studies in Broadmeadow Estuary (Aquafact 2008), Environmental Baseline Survey of the Eirgrid Interconnector (Fugro Survey Ltd 2008); • Geomorphology: INFOMAR bathymetric and habitat datasets (Geological Survey of Ireland (GSI)), Regional habitat classification maps for the Irish Sea (Joint Nature Conservation Committee, United Kingdom (UK)) and Admiralty chart data for the Fingal Coastline; • Marine Mammal data for Irish Whale and Dolphin Group (IWDG) database for sightings in the survey area. Assessments on the population of harbour porpoises including those within the Rockabill to Dalkey Island Special Area of Conservation (SAC) (Berrow et al. 2008; 2011; 2013). Uploading of sightings from IWDG web based database from 1986 to 2013; • Fish Species: Centre for Environment, Fisheries and Aquaculture Science (Cefas) publications and International Council for the Exploration of the Sea (ICES) publications; and • Fisheries Sensitivity Maps in British Waters (Coull et al. 1998), Mapping Spawning and Nursery Areas of Species to be Considered in Marine Protected Areas (Marine Conservation Zones) (Ellis et al. 2010), Spawning and Nursery Grounds of Selected Fish Species in UK Waters (Ellis et al. 2012).

9.2.2 Field Surveys Geomorphology A bathymetric survey was carried out along the proposed outfall pipeline route (marine section) by GSI under contract to TechWorks Marine Limited in February 2013 and March 2013. Survey work was carried out by the RV Geo, which is run by the GSI for use on the INFOMAR programme. The RV Geo is a 7.5m rigid inflatable

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boat (RIB) used to map very shallow/intertidal water depths and is equipped with a Systems Engineering and Analysis 468 kilohertz (kHz) Swathplus interferometric mapping system allowing for wide swath coverage in shallow water depths. The data were reviewed for both depths (bathymetry) and reflectivity (backscatter relating to seabed hardness) for this assessment, with the former dataset rendered into a digital terrain model based on a 2m grid size. The data have subsequently been used to describe the background environment for the marine ecological assessment. The proposed outfall pipeline route (marine section) was further surveyed on two occasions in 2015 during geotechnical and archaeological ground investigations. The former was undertaken between July 2015 and October 2015 by Causeway Geotech using sidescan sonar, boreholes and vibrocores (Causeway Geotech 2015), whilst the latter was carried out by Irish Hydrodata Ltd in August 2015 using echo sounder, sidescan sonar, magnetometer and a pinger sub-bottom profiler (Irish Hydrodata 2015). Data from both surveys have been reviewed for this assessment. Marine Benthos and Sediments A detailed marine environmental survey was carried out along the proposed outfall pipeline route (marine section) and surrounding environments by Benthic Solutions Limited (BSL) over four survey periods as follows:

• Broad survey assessment of benthic conditions between Dublin Bay and Skerries in August 2012 (29 sampling stations). As a regional assessment, this survey covered other possible outfall locations not selected for the final route. The eight sites pertinent to the Proposed Project were targeted for further assessments in 2013 and 2017 (see bullet points below); • The water quality component of the August 2012 survey was repeated in December 2012 (three sampling stations); • Assessment of eight sampling stations focused along the proposed outfall pipeline route (marine section) in July 2013; and • Repeat assessment of eight sampling stations focused along the proposed outfall pipeline route (marine section) in August 2017. The timings of these studies were established to encompass the seasonal maxima for the marine benthos (i.e. both established and recently settled communities) and the seasonal extremes within the water quality. The surveys included an assessment of the macroinvertebrate communities and habitat types at all selected locations, along with some water quality profiling and sampling. Physico-chemical parameters of the shallow marine sediments were recorded during each of these surveys using grab sampling, whilst additional information of sub-surface sediments was further recorded down to a depth of 1.2m using a 3m pneumatic vibrocorer along the proposed outfall pipeline route (marine section) in the survey carried out by Causeway Geotech in 2015. Details of the benthic environmental surveys are provided in Appendix A9.1. Results of marine survey acquisition are discussed in Section 9.3.2 to 9.3.4, with a summary plotted in Figure 9.1 Summary of Field Survey Operations for the Proposed Outfall Pipeline Route (Marine Section). Field acquisition equipment and processing method statements are included in Appendix A9.1. Water Quality Profiling and Sampling Field observations of water column structure and water quality sampling were acquired to provide a snapshot of ecological conditions at the proposed outfall pipeline route (marine section) over the year. The survey was carried out at three locations during August (summer) and December (winter) in 2012 (refer to Figure 9.1 Summary of Field Survey Operations for the Proposed Outfall Pipeline Route (Marine Section) and Table 9.12), with further sampling acquired at a control site and at the proposed outfall discharge point in 2013 and in 2017. A full profile of the water column was undertaken using a YSI6600 V2 Sonde, whilst discrete water samples were also acquired at the surface mid-depth and seabed using a Niskin water sampler. The sonde was equipped with sensors for measuring depth, temperature, conductivity (derived salinity), pH, dissolved

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oxygen and turbidity with duplicate profiles acquired at different states of the tide. Water samples were stored frozen or fixed prior to analysis at the laboratory for heavy and trace metals, total petroleum hydrocarbons (TPHs) in the first two survey years and dissolved organic carbon (DOC) along with a range of nutrients, silicon and chlorophyll for all surveys. Results are shown in Section 9.3.5. Fish and Shellfish A scientific 2m beam trawl survey (11mm mesh) and a beach seine net survey were conducted in September 2015 and again in September 2017 by the Aquatic Services Unit (ASU) from University College Cork (see ASU Report in Appendix A9.1) to investigate juvenile fish near the proposed outfall pipeline route (marine section). In the same month, a common whelk (Buccinum undatum) survey was carried out by RPS to provide catch data to support this EIAR and planning application (see RPS Report in Appendix A9.1). The beam trawl survey consisted of four lines positioned perpendicular to the shore in the area of the proposed outfall pipeline route (marine section). Along each line, four 1km to 2km trawls were completed at a speed of 1.5 knots (see Figure 1 of the ASU Report in Appendix A9.1). One line was positioned over the proposed outfall pipeline route (marine section), two lines were located 200m to the north and south of the proposed outfall pipeline route (marine section), and the final line was for reference (control) purposes and was positioned 1km to the north. A small local fishing vessel was chartered to carry out this survey. Four locations along the Portmarnock shore were sampled using the 45m beach seine net. As with the beam trawls, one station was positioned at the centre of the proposed outfall pipeline route (marine section), two stations were located to the north and south of the proposed outfall pipeline route (marine section), and the fourth reference station was 1km north of the proposed outfall pipeline route (marine section). Nine stations in the area of the proposed outfall pipeline route (marine section) were sampled during the whelk survey (see Figure 5.1 of the RPS Report in Appendix A9.1), reflecting areas and methods commercially used by local fishing vessels. At each station, a string of 50 whelk pots, baited with brown crab (Cancer pagurus) and lesser-spotted dogfish (Scyliorhinus canicula), were deployed and left for a soak time of up to 24 hours before recovery and processing. In every tenth pot, the total length (mm) of each individual and the collective weight of all whelk were recorded. All other species caught were also identified and enumerated. The total weight of all whelk landed per station was recorded; this was estimated on-site, and later confirmed when the pots were landed and weighed at market. Positions for each station were recorded when the first and last pots were deployed and recovered. Plankton Plankton was assessed at the same time as the water quality sampling to provide a snapshot of activity and productivity in the waters surrounding the proposed outfall pipeline route (marine section) in 2012. The presence of phytoplankton was tested for during water quality sampling by analysing water samples for chlorophyll. A qualitative (and semi-quantitative) analysis for zooplankton, was also undertaken at selected locations during both summer and winter sampling campaigns using a vertical tow net trawl (250µm mesh size) technique at three locations across the proposed outfall pipeline route (marine section) and again in July 2017. The recovered material was analysed for their zooplankton content by a pelagic taxonomist at the Marine Biological Association in Plymouth. Baldoyle Estuary Walkover This survey was undertaken to support the earlier coastal and intertidal habitat mapping carried out by Ecoserve in 2005, and a more detailed assessment undertaken for the National Parks and Wildlife Service (NPWS) on the saltmarsh community in Baldoyle Estuary SAC (Site Code: 00199) in 2006 (McCorry and Ryle 2009). The site was visited on 13 November 2013 by a BSL botanist, and the habitat mapping prepared by McCorry and Ryle (2009) reviewed in the field in relation to the current conditions at the site and the proposed outfall pipeline route (marine section). GIS shapefiles, prepared by McCorry and Ryle (2009), were loaded

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onto electronic media and underlain by aerial photographs (Google Maps) to allow for an accurate assessment in the field of the extent of habitat types as previously described and mapped and to document any changes. A photographic record of the habitats recorded was also made which have been geo-referenced and provided in Appendix A9.1. Surveys for Reefs (1170) on Ireland’s Eye – Rockabill to Dalkey Island Special Area of Conservation The Rockabill to Dalkey Island SAC (Site Code: 003000) was established in April 2013 and designated for the marine Habitats Directive Annex I qualifying interest Reefs and the Annex II species harbour porpoise (Phocoena phocoena). As the proposed outfall pipeline route (marine section) (including the proposed marine diffuser) is located within this SAC, additional surveys were carried out to cover both qualifying interests. Within the Rockabill to Dalkey Island SAC, two community types are recorded within the Annex I habitat, namely intertidal reef community complex and subtidal reef community complex (Reefs 1170). Intertidal and subtidal surveys were undertaken in 2010 and 2011 (MERC 2010; 2012a; 2012b). These data were used to determine the physical and biological nature of the Annex I habitat. The area and quality of these qualifying features were based on broad interpolations from only limited drop-down video. Therefore, two additional survey campaigns were carried out to establish a greater understanding of these features within the vicinity of the proposed outfall pipeline route (marine section). The surveys were undertaken in two phases. The initial phase of the investigation was based on a detailed video inspection of features identified in the bathymetry by BSL in May 2015 (BSL 2015a). During this survey, additional bathymetry was carried out using a precision echo sounder to infill deficiencies in existing data close to the island’s cliffs and rock outcrops. Detailed photography was also carried out using a MOD4 high resolution camera on nine drop-down video locations taken along the subtidal reefs around the island and at the proposed outfall pipeline route (marine section) (refer to Figure 9.1 Summary of Field Survey Operations for the Proposed Outfall Pipeline Route (Marine Section)). The results of this survey were used to identify key areas for the second phase of operations using an intertidal walk-over (three sites) and detailed subtidal transects (four sites) using scientific divers (refer to Figure 9.1 Summary of Field Survey Operations for the Proposed Outfall Pipeline Route (Marine Section)). This later phase was carried out by BSL and Aquatic Survey and Monitoring Limited in July 2015. Surveys for the Harbour Porpoise – Rockabill to Dalkey Island Special Area of Conservation A considerable number of surveys and sightings of the harbour porpoise have been gathered along the Irish east coast, including the area between Ireland’s Eye and Skerries to the north (e.g. Pollock et al. 1997; Reid et al. 2003; Ó Cadhla et al. 2004; Small Cetaceans in the European Atlantic and North Sea (SCANS-II) 2008; Berrow et al. 2010; Berrow et al. 2011; Baines and Evans 2012; Wall et al. 2012). The boundary of the SAC was supported by targeted surveys of the harbour porpoise community conducted in 2008 (Berrow et al. 2008). Site specific information of cetacean activity in the vicinity of the proposed outfall pipeline route (marine section) and this section of the SAC was obtained over a two-year programme based on three integrated methods in line with best practice; these were land based vantage point surveys, boat based transects and Static Acoustic Monitoring. Visual surveys were only carried out in favourable weather conditions (a sea state of a Beaufort wind force of 2 or less and visibility >6km). Monthly land based surveys were conducted from sites at Loughshinny for six months and Howth Head for 24 months. Single platform line-transect boat surveys were also conducted bi-monthly following a pre-determined route and standardised design. Finally, static acoustic monitoring using C-PODs was conducted for six months at a single site off Loughshinny and for 24 months at three locations off Portmarnock. Full details of these surveys are reported in Appendix A9.1. TechWorks Marine Limited deployed passive acoustic monitoring recorders at three mooring sites along the proposed outfall pipeline route (marine section) between March 2015 and March 2017. An additional site was located east of Loughshinny in March 2015 for six months. Each mooring was fitted with a C-POD self- contained click detector which logs the echolocation clicks of porpoises and dolphins. The recovered data were interpreted by the IWDG. All C-POD data were analysed using only high probability clicks, which

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reduced the possibility of false positives (i.e. recorded as present when there were in fact no dolphins or porpoise present). Harbour porpoise detections were extracted as detection positive minutes per day and were analysed statistically for temporal and geographical trends. Porpoise detections were analysed with respect to season (spring, summer, autumn and winter), diel cycle (day and night-time), tidal state (ebb, flood, slack high, slack low) and tidal phase (spring, neap) at a resolution of one hour. IWDG further supported the Proposed Project by providing regular observations from both sea and land based surveys for cetaceans over the same survey period. Land based observation sites were located on the cliffs at Howth Head, looking directly over the proposed outfall pipeline route (marine section) for a 24-month period, as well as the Loughshinny Martello Tower, for a six-month period which recorded 20 hours of land based monitoring conducted over six survey days. The weather was favourable throughout with no swell, with a sea state of a Beaufort wind force of 2 or below and a visibility of 6km to 20km. Marine mammals were sighted on 86% of survey days. The survey effort conducted from Howth Head amounted to around 144 hours (23 surveys) between 18 March 2015 and 11 March 2017. Environmental conditions were favourable with no swell, sea state of a Beaufort wind force of 2 or below for 99% and visibility greater than 6km for 97% of survey effort. Marine mammals were sighted on 100% of survey days. Eleven independent boat based surveys were carried out from April 2015 to January 2017 over a total of 897km of track-lines. Environmental conditions were favourable with visibility of more than 6km for 91% of the survey time and swell of less than 1m for 100% of survey effort. A sea state of a Beaufort wind force of 2 or below was recorded for 8 of the 11 surveys. However, a sea state of a Beaufort wind force of 2 or below was recorded for only 8% of the survey time carried out in April 2015, 36% of the survey time in June 2015 and 46% of the survey team during December 2016. Marine mammals were sighted on all survey days. The software programme DISTANCE was used for calculating detection functions, which is the probability of detecting an object a certain distance from the track-line and used to calculate the density of animals on the track-line of the vessel. A detection function was calculated from each boat survey, provided that a sufficient number of sightings were made to provide a robust estimate. All of these datasets have been integrated and are reported in Appendix A9.2. Ambient Noise Recording The possible impact of noise to the marine environment was further assessed based on two assessments. The first was the recording of the ambient noise level from a buoy-mounted recorder on a location close to the proposed marine diffuser location (53°24.901'N and 006°2.978'W) between 30 July 2015 and 1 September 2015 by the University of Catalonia and TechWorks Marine Limited. For the recording, a duty cycle was configured with 15 minutes on and 50 minutes off. The hydrophone sensitivity recording stored on the unit was -168dB re 1 V/ μPa and the data were sampled at 16kHz in 24 bits. The shallow nature of the site (generally <20m) was sufficient to affect the propagation of the sound in this area. The second assessment was based on modelling the propagation of sound in this area and the likely source from construction activities, and is described in Section 9.2.3.

9.2.3 Underwater Noise Modelling Following the ambient noise assessment (previous section), the possible impact of noise to the marine environment during the Construction Phase of the Proposed Project was modelled by Quiet Oceans in 2017 (refer to Appendix A9.1). The objective of the study was to map the noise propagation of the dredging activity at one specific position for three frequencies, 125Hz, 1kHz and 8kHz, third octave as defined by international standards (ANSI S1.11, 2004; IEC. 1995) for a single environmental condition. In a similar manner to weather forecasting systems, the model produces an estimate of the spatio-temporal distribution of noise levels generated by human activities at sea, aggregating multiple sources. The production of statistical soundscapes

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effectively characterises the spatio-temporal emergence of anthropogenic noise from the real environmental conditions of the area. The noise received at a particular position in the marine environment depends on the characteristics of the sound source(s) and the propagation through the marine environment. Noise propagation, and therefore noise levels, are mainly determined by the following:

• Bathymetry; • The nature of seabed; • Oceanographic conditions such as temperature and salinity; • Currents; • Sea level; and • The weather conditions such as the wind (and consequently waves) and rainfall intensity. The potential sound source levels used within the model were based on trailer suction hopper dredging (TSHD) and impact piling (600mm) (considered as worst case scenario for Proposed Project) based on literature sources (Parvi 2008; Robinson et al. 2011; De Jong et al. 2008; Talisman Energy et al. 2004; ITAP 2008). The outputs were shown as noise maps showing maximum 5th percentile (or exceedance level) for the full water column for the 125Hz, 1kHz and 8kHz third-octave bands.

9.2.4 Impact Assessment Methodology The assessment process firstly requires that ecological features are valued based on their nature conservation interest. For the purposes of this assessment, ecological values will be determined using the criteria defined in Table 9.1. The criteria used is based upon Chartered Institute of Ecology and Environmental Management (CIEEM) and National Roads Authority (NRA) guidelines, which outline up to eight different geographic scales (i.e. international through to local) by which ecological value can be assigned (CIEEM 2010; NRA 2009). Here, ecological values are re-defined ‘very high’ through to ‘negligible’ as defined in Table 9.1. In the case of internationally or nationally designated sites, assigning ecological criteria is generally straightforward, as these designated sites typically fall strictly within the relevant categories. Professional judgement is more important in assigning further values that may relate to ecological sensitivities. In assigning value to a species or habitat, it is necessary to consider its distribution and status, typically based on historical records and occurrence between geographic areas. Legal protection needs to be considered separately from value. Where a feature has value at more than one level, its highest level of value will take precedence. For example, a species designated integral to an SAC and as an Annex II species of Council Directive 92/43/EEC on the conservation of natural habitats and of wild fauna and flora (Habitats Directive) should be considered as being internationally important, even though its SAC value is considered to be of national importance. The features for which the site has been designated at each level may differ and should therefore be valued accordingly. Features of the sites that are not the reasons for its designation(s) should be assessed and valued according to their intrinsic value.

Table 9.1: Ecological Value Criteria

Ecological Value Examples Very high ‘European Site’, including SAC, Site of Community Importance (SCI) and/or Special Protection Area (SPA). (International Species and/or Habitats that form the primary cited interests of SPAs and/or SACs. importance) Proposed Special Protection Area (pSPA) and/or candidate Special Area of Conservation (SAC). Features essential to maintaining the coherence of the Natura 2000 Network. Site containing ‘best examples’ of the habitat types listed in Annex I of the Habitats Directive. Salmonid water designated pursuant to the European Communities (Quality of Salmonid Waters) Regulations 1988 (S.I. No. 293 of 1988).

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Ecological Value Examples High Species and/or habitats that contribute to the integrity of an SPA and/or SAC but which are not cited as a (National) species for which the site is designated. Sites designated or proposed as a Natural Heritage Area. Statutory Nature Reserve or a National Park. Resident or regularly occurring populations (assessed to be important at the national level) of the following: - Species protected under the Wildlife Acts 1976-2000; and/or - Species listed on the relevant Red Data list. Sites containing 'viable areas' of the habitat types listed in Annex I of the Habitats Directive. Medium Areas of Special Amenity. (County) Resident or regularly occurring populations (assessed to be important at the County level) of the following: - Species of bird, listed in Annex I and/or referred to in Article 4(2) of Directive 2009/147/EC of 30 November 2009 of the European Parliament and of the Council on the conservation of wild birds (Birds Directive); - Species of animal and plants listed in Annex II and/or IV of the Habitats Directive; - Species protected under the Wildlife Acts (1976-2000); and/or - Species listed on the relevant Red Data list. Sites containing area or areas of the habitat types listed in Annex I of the Habitats Directive that do not fulfil the criteria for valuation as of international or national importance. Sites containing semi-natural habitat types with high biodiversity in a county context and a high degree of naturalness, or populations of species that are uncommon within the county. Sites containing habitats and species that are rare or are undergoing a decline in quality or extent at a national level. Locally important populations of priority species or habitats or natural heritage features identified in a local area plan (if one has been prepared). Resident or regularly occurring populations (assessed to be important at the local level) of the following: - Species of bird listed in Annex I and/or referred to in Article 4(2) of the Birds Directive; - Species of animal and plants listed in Annex II and/or IV of the Habitats Directive; Low - Species protected under the Wildlife Acts (1976-2000); and/or (Local) - Species listed on the relevant Red Data list. Sites containing semi-natural habitat types with high biodiversity in a local context and a high degree of naturalness, or populations of species that are uncommon in the locality. Sites or features containing common or lower value habitats, including naturalised species that are nevertheless essential in maintaining links and ecological corridors between features of higher ecological value. Sites containing small areas of semi-natural habitat that are of some local importance for wildlife. Negligible Sites of features containing non-native species that are of some importance in maintaining habitat links. (Site) All other features that are widespread and common and which are not present in locally, regionally or nationally important numbers which are considered to be of low or poor ecological value. The effects on ecological features are then judged in terms of magnitude and duration. The following parameters are considered:

• Physical nature; • Type (positive/negative, direct/indirect); • Range of species and habitats affected; • Population sizes of species and habitats affected; • Spatial extent; • Reversibility; • Duration; • Confidence in prediction; and • Cumulative effects. The magnitude of an impact is assessed using criteria set out in Table 9.2. Magnitude refers to the size of an impact, and is determined on a quantitative basis where possible (CIEEM 2016; NRA 2009). This may relate to the area of habitat lost to the development footprint or predicted loss of population of a particular species.

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Table 9.2: Criteria for Determining the Magnitude of Potential Ecological Impact

Magnitude Examples The proposal (either on its own or with other proposals) will result in a total loss or very major alteration to key Very high elements/features of the baseline conditions such that post-development character/composition/attributes will be fundamentally changed and may be lost from the site altogether. The proposal (either on its own or with other proposals) will result in a major alteration to key elements/features of High the baseline (pre-development) conditions such that post-development character/composition/attributes will be fundamentally changed. The proposal (either on its own or with other proposals) will result in a loss or alteration to one or more key Medium elements/features of the baseline conditions such that post-development character/composition/attributes of baseline would be partially changed. The proposal (either on its own or with other proposals) will result in a minor shift away from baseline conditions. Low Change arising from the loss/alteration will be discernible but underlying character/composition/attributes of baseline conditions would be similar to pre-development circumstances/patterns. The proposal (either on its own or with other proposals) a very slight change from baseline condition. Change Negligible barely distinguishable approximating to the ‘no change’ situation.

Duration is defined as the time for which the impact is expected to last before recovery, i.e. the return to baseline conditions (refer to Table 9.3).

Table 9.3: Duration of Impact

Duration Criteria Permanent Effects continuing indefinitely beyond one human generation (approx. 25 years), except where there is likely to be a substantial improvement after this period, whereby these would be described as ‘very long-term effects’. Temporary Long-term (15 to 25 years or longer) Medium (5 to 15 years) Short-term (up to 5 years)

Determination of Significance The significance of the impact is a correlation of the impact magnitude and ecological value. The matrix used for the assessment of significance presented in Table 9.4. The results from the impact matrix are not definitive. The overall significance of impact is determined to be a combination of the impact matrix and an evidence based approach. Once identified, and characterised for magnitude and significance, each potential impact is assigned a confidence of prediction. IEEM guidance (IEEM 2010) outlines the following terminology for outlining the likelihood of impact occurrence:

• Certain (100%); • Near-certain (95–100%); • Probable (50–95%); • Unlikely (5–50%); and • Extremely Unlikely (0–5%). Potential impacts described in later sections assume no specific mitigation measures. Specific mitigation measures are proposed in Section 9.7, where required, to reduce impacts identified as being of ‘Moderate’ and/or ‘Major Adverse’ significance. A statement of residual impacts is then provided.

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Table 9.4: Impact Significance Matrix

Ecological Value Impact Significance Very High High Medium Low Negligible

Very High Major Major Major Moderate Minor

High Major Major Moderate Minor Negligible

Medium Major Moderate Minor Minor Negligible

Magnitude Low Moderate Minor Minor Negligible Negligible

Negligible Minor Negligible Negligible Negligible Negligible

A summary of the generic definition of impact significance is outlined in Table 9.5. As not all impacts create an adverse effect, the definition for positive or beneficial impacts are also shown for the same impact significance.

Table 9.5: Definition of Impact Significance

Impact Definition

Major Adverse Considerable detrimental or negative impact to an environmental resource or receptor (by extent, duration or magnitude) of more than local significance or in breach of recognised acceptability, legislation, policy or standards.

Moderate Adverse Limited detrimental or negative impact to an environmental resource or receptor (by extent, duration or magnitude) which may be considered significant.

Minor Adverse Slight, very short or highly localised detrimental or negative impacts to an environmental resource or receptor.

Negligible No significant impacts to an environmental resource or receptor.

Minor Beneficial Slight, very short or highly localised advantageous or positive impact to an environmental resource or receptor.

Moderate Beneficial Limited advantageous or positive impact to an environmental resource or receptor (by extent, duration or magnitude) which may be considered significant.

Major Beneficial Considerable advantageous or positive impact to an environmental resource or receptor (by extent, duration or magnitude) of more than local significance.

Aspects of the Proposed Project That Have the Potential to Impact on the Marine Environment Please refer to Chapter 4 Description of the Proposed Project in Volume 2 Part A of this EIAR for full details on the Construction Phase and Operational Phase methodology for the Proposed Project. The proposed outfall pipeline route (marine section) commences in Baldoyle Estuary and runs approximately 5.9km to terminate approximately 1km north-east of Ireland’s Eye, located approximately 4.5km offshore. The proposed construction method is a combination of microtunnelling and subsea pipe laying techniques within a 250m wide proposed construction corridor. The tunnelled section will run beneath Baldoyle Estuary to an approximate distance of 2km seaward of Velvet Strand to below the low water mark. The proposed outfall pipeline route (marine section) east of this point will be constructed using surface techniques involving the excavation of a trench from the tunnel termination point to the discharge location (approx. 4km). The trench (trapezoidal in shape) is envisaged to be 5m deep and 5m wide at the base, and between 20m and 40m wide at the surface subject to seabed sediment type. A proposed marine diffuser will be constructed at the end of the proposed outfall pipeline route (marine section).

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At the tunnel/subsea pipeline interface, approximately 600m offshore, a temporary structure will be required consisting either of a cofferdam or a pre-excavated section of trench (filled with loose sand/granular material sourced from elsewhere along the trench alignment) to retrieve the Tunnel Boring Machine TBM from the microtunnelled section. A subsea fibre optic cable crosses the proposed outfall pipeline route (marine section) at approximately chainage 4,500m. This cable has to be protected in situ using interlocking sheet piles while the dredging and pipelaying operations progress. On installation, the proposed outfall pipeline route (marine section) will be constructed using long length large diameter polyethylene pipes, which will be towed by sea from the pipe manufacturer to the pipe assembly area selected by the appointed contractor(s). The pipes will be towed in maximum lengths of 650m and assembled into string lengths defined by the appointed contractor(s) with the use of mechanical joints or flanged connections. The pipes will be sealed and slightly pressurised to aid floating. Concrete weight collars will be placed on the pipe string and secured in place. The pipe assembly will take place along a at Dublin port or in sheltered waters along the route of the proposed outfall pipeline (marine section). The Construction Phase of the Proposed Project has the potential to impact on the marine environment in the following ways:

• Surface trenching has the potential to impact the benthic environment through physical disturbance and smothering during the excavation and sidecasting of the spoil and through the settlement of displaced suspended sediment over a greater area. This has the potential to impact the reef habitats found on Ireland’s Eye and the Rockabill to Dalkey Island SAC; • All construction operations at the proposed temporary construction compounds neighbouring the estuary, or from floating plant during trenching, installation and piling has the potential to introduce pollution into the marine environment. Sensitive receptors include marine life, including nursery fish species, pinnipeds (seals) and cetaceans; • Construction of the terrestrial elements of the Proposed Project, which could result in contaminated runoff entering the Mayne River and Tolka River catchments (see Section 11.9 to Section 11.14 of Chapter 11 Biodiversity (Terrestrial and Freshwater Aquatic) in Volume 3 Part A of this EIAR) entering the marine environment; • The noise created during construction has the potential to impact sensitive receptors within the proposed outfall pipeline route (marine section) construction corridor through injury from noise or avoidance. Sensitive receptors include nursery fish species, pinnipeds (seals) and cetaceans, in particular the harbour porpoise. The proposed outfall pipeline route (marine section) falls within the Rockabill to Dalkey Island SAC; • The construction of the proposed outfall pipeline route (marine section) (including the proposed marine diffuser) will result in a permanent loss of the habitat over a very small area at the proposed marine diffuser location and the introduction of a new hard substrate; • The duration of the Construction Phase could affect the seasonal migration of important marine species, including salmonids and the harbour porpoise, nursery fish species in the area or the breeding season of seabirds nesting on Ireland’s Eye SPA; • The use of microtunnelling techniques has the potential (albeit low risk) to release air or bentonite via a breakout into the marine environment; and • During the Operational Phase, the treated wastewater discharged into the Irish Sea has the potential to affect water quality in the area. This can impact the quality of nearby beaches as well as neighbouring shellfish waters.

9.2.5 Non-Statutory Consultation The issues raised as a result of non-statutory consultation on the Proposed Project are included in Table 9.6.

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Table 9.6: Issues Raised During Non-Statutory Consultation on the Proposed Project.

Stakeholder Submission Details Environmental Impact Assessment Report Chapter Reference

An Taisce • Concerns raised about the potential impact • The Natura Impact Statement (NIS) (received 17 January 2014) on protected areas: Baldoyle Bay SAC (Site provides details on the assessment of Code: 000199), Baldoyle Bay SPA (Site impacts of the Proposed Project on Code: 004016) and the Rockabill to Dalkey SACs and SPAs in the Zone of Island SAC (Site Code: 003000). Influence. • Environmental Impact Statement (EIS) • Sections 9.4 and 9.5 provide details on should address potential impacts on each potential impacts, while mitigation protected area and relevant mitigation measures are provided in Section 9.7. measures. • See Chapter 4 Description of the • Water quality of discharge must be tested Proposed Project in Volume 2 Part A of frequently to ensure that chemical and this EIAR. nutrient inputs do not have a negative effect on porpoise population and reef habitat within the Rockabill to Dalkey Island SAC. BirdWatch Ireland • Concerns regarding activities in the vicinity • The NIS provides details on the (received 12 December 2013) of Baldoyle Bay SPA (Site Code: 004016); assessment of impacts of the Proposed • Concerns regarding the proximity of the Project on SACs and SPAs in the Zone proposed outfall pipeline route (marine of Influence. section) to Ireland’s Eye SPA (Site Code: 004117); • Potential impact of nutrient reduction on the estuarine environment. Department of Arts, Heritage, • With regard to EIS, an ecological survey of • Chapter 9 Biodiversity (Marine), Regional, Rural and Gaeltacht the entire Proposed Project site and Chapter 10 Biodiversity (Marine Affairs/National Parks and Wildlife proposed pipeline routes should be carried Ornithology and Chapter 11 Biodiversity Service (NPWS) out. Where ex situ impacts are possible, (Terrestrial and Freshwater Aquatic) in (Formerly Department of Arts, survey work may be required outside of the Volume 3 Part A of this EIAR provide a Heritage and the Gaeltacht) Proposed Project sites. full ecological survey of the Proposed • The impact of the Proposed Project on the Project including ex situ impacts and (received 10 January 2014) flora, fauna and habitats present should be provide details on potential impacts on assessed. In particular, the impact of the ecology. Proposed Project should be assessed, • An NIS has been prepared for the where applicable, with regard to legislation Proposed Project. relating to habitats and species. • The Proposed Project should be subject to Appropriate Assessment screening and, where necessary, Appropriate Assessment as per Article 6.3 of the Habitats Directive. • Consultation with the relevant Local Authorities is recommended to determine if there are any projects or plans which alone or in combination could impact on any Natura 2000 sites. Inland Fisheries Ireland (IFI) • EIS should include an assessment • Chapter 9 Biodiversity (Marine), establishing the current baseline ecological Chapter 10 Biodiversity (Marine (received 11 December 2013) conditions, detail construction and Ornithology and Chapter 11 Biodiversity operational activities and predict the impact (Terrestrial and Freshwater Aquatic) of future changes to the baseline. provide details on the baseline • Water quality assessment should be carried ecological conditions. Chapter 4 out in accordance with all relevant existing Description of the Proposed Project in

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Stakeholder Submission Details Environmental Impact Assessment Report Chapter Reference national and European legislation; Volume 2 Part A of this EIAR provides • Require detailed hydraulic and water quality details on the Proposed Project. modelling to assess the impact on water • See Chapter 8 Marine Water Quality. quality at the location of the proposed outfall Section 9.3.5 also provides details on pipeline route (marine section). water quality with respect to marine • The EIS should provide a full and detailed ecology. evaluation on the likely impacts of the • Chapter 9 Biodiversity (Marine), Proposed Project on groundwater, Chapter 10 Biodiversity (Marine freshwater, estuarine and coastal ecology. Ornithology and Chapter 11 Biodiversity • Mitigation strategies to be developed to (Terrestrial and Freshwater Aquatic) in avoid impacts on water quality and habitat Volume 3 Part A of this EIAR provide a ecology. full and detailed evaluation of the likely • The EIS should assess the predicted impacts of the complete project on impacts of noise and vibration during the freshwater, estuarine and coastal construction and operation of the Proposed ecology. Chapter 17 provides details on Project. groundwater. • All measures necessary should be taken to • Section 9.7 provides details on ensure protection of local aquatic ecological mitigation measures. integrity, in the first place by complete • Section 9.4 provides an assessment of impact avoidance and, as a secondary noise and vibration impacts from the approach, through mitigation by reduction Construction Phase. No significant and remedy. noise impact is predicted during the Operational Phase.

Irish Whale and Dolphin Group • Scoping document makes no provision to • Section 9.4 assesses the impact of the (IWDG) assess the use of the marine area Proposed Project on harbour porpoise. (received 14 November 2013) influenced by the Proposed Project by • An NIS has been prepared for the harbour porpoise. Proposed Project. • Concerns raised over the proposed outfall • Section 9.2.2 provides details on pipeline route (marine section) location as baseline monitoring completed. the area is frequently used by harbour porpoise and is adjacent to the SAC designated for harbour porpoise (Rockabill to Dalkey Island SAC) • Recommend static acoustic monitoring using C-PODS be carried out for a minimum of 12 months or 24 months as per best practice. Marine Institute • EIS should address the potential impacts, • Section 9.4 addresses potential impacts (received 08 December 2013) particularly during the installation phase of on fisheries. the proposed outfall pipeline route (marine • Section 9.3.3 provides details on section), on inshore fishing activity. sediment chemistry. • Where any dredged/excavated materials are to be disposed of at sea, data should be provided on the physical and chemical characteristics of the materials.

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9.3 Baseline Environment

9.3.1 Designated Sites for Nature Conservation A summary of the SACs in the marine environment is included in Table 9.7. It should be noted that potential impacts to SPAs are discussed separately in Chapter 10 Biodiversity (Marine Ornithology) while those on terrestrial designated sites for nature conservation are discussed in Chapter 11 Biodiversity (Terrestrial and Freshwater Aquatic). An NIS has also been completed for the Proposed Project.

Table 9.7: Marine Special Areas of Conservation Within the Vicinity of the Proposed Project

Site Site Name Habitat Habitat Name Distance Code Code 000199 Baldoyle 1140 Mudflats and sandflats not covered by seawater at low tide Within Bay SAC 1310 Salicornia spp. and other annuals colonising mud and sand Proposed Project area 1330 Atlantic salt meadows (Glauco-Puccinellietalia maritimae) 1410 Mediterranean salt meadows (Juncetalia maritimi) 000202 Howth 1230 Vegetated sea cliffs of the Atlantic and Baltic coasts 2.6km south Head SAC 4030 European dry heaths 000204 Lambay 1170 Reefs 9.3km north Island SAC 1230 Vegetated sea cliffs of the Atlantic and Baltic coasts 000205 Malahide 1140 Mudflats and sandflats not covered by seawater at low tide 2.5km north Estuary 1310 Salicornia spp. and other annuals colonising mud and sand SAC 1330 Atlantic salt meadows (Glauco-Puccinellietalia maritimae) 1410 Mediterranean salt meadows (Juncetalia maritimi) 2120 Shifting dunes along the shoreline with Ammophila arenaria (white dunes) 2130 Fixed coastal dunes with herbaceous vegetation (grey dunes) 000206 North 1140 Mudflats and sandflats not covered by seawater at low tide 2.3km south Dublin Bay 1310 Salicornia spp. and other annuals colonising mud and sand SAC 1330 Atlantic salt meadows (Glauco-Puccinellietalia maritimae) 1410 Mediterranean salt meadows (Juncetalia maritimi) 2120 Shifting dunes along the shoreline with Ammophila arenaria (white dunes) 2130 Fixed coastal dunes with herbaceous vegetation (grey dunes) 1210 Annual vegetation of drift lines 2110 Embryonic shifting dunes 2190 Humid dune slacks 000208 Rogerstown 1130 Estuaries 8.5km north Estuary 1140 Mudflats and sandflats not covered by seawater at low tide SAC 1310 Salicornia spp. and other annuals colonising mud and sand 1330 Atlantic salt meadows (Glauco-Puccinellietalia maritimae) 1410 Mediterranean salt meadows (Juncetalia maritimi) 2120 Shifting dunes along the shoreline with Ammophila arenaria (white dunes) 2130 Fixed coastal dunes with herbaceous vegetation (grey dunes) 000210 South 1140 Mudflats and sandflats not covered by seawater at low tide 7.6km south Dublin Bay SAC 002193 Ireland’s 1230 Vegetated sea cliffs of the Atlantic and Baltic coasts 0.8km south Eye SAC 1220 Perennial vegetation of stony banks 003000 Rockabill to 1170 Reefs Within Dalkey Proposed Island SAC Project area

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9.3.2 Geomorphology and Seabed Sediments The detailed bathymetry of the proposed outfall pipeline route (marine section) is shown in Figure 9.2 Summary of Bathymetry Data for the Proposed Outfall Pipeline Route (Marine Section). The bathymetry can be separated into the three sediment types. The proposed outfall pipeline route (marine section) passes beneath the medium sands of Velvet Strand along the Portmarnock coastline, to beneath a beach break with an increased gradient of around 2°. This then passes into consistent shallow shelving fine sand (gradient <0.5°) out to a distance of 3.3km from the beach with no bedforms observed along the route. Here, the slope steepens to approximately 3° for around 150m, before returning to the shallow slope, but also becomes rougher and harder, indicative of mixed gravelly sand with some large sediments clasts (such as cobbles). At 4.8km from the beach, the seabed returns to a smoother morphology but remains at a high reflectivity to the proposed marine diffuser location. This is indicative of a thin veneer of fine sands overlying a mixed gravelly sand and shell. The proposed outfall pipeline route (marine section) was further assessed using sidescan sonar data, which confirmed the above description. A small area of increased reflectivity was recorded at the landfall end of the proposed outfall pipeline route (marine section) just below the wave break area, interpreted as an area of increased sediment compaction. No hard reef features (geogenic or biogenic) were recorded along the proposed outfall pipeline route (marine section). During the benthic surveys, detailed sediment analysis was undertaken at nine sites near the proposed outfall pipeline route (marine section) and surrounding area between 2012 and 2017. In addition, sediments were also acquired at seven core locations along the proposed outfall pipeline route (marine section). A summary of the specific particle size results are outlined in Appendix A9.1 and presented geographically in Figure 9.3 Sediment Changes Near the Proposed Outfall Pipeline Route (Marine Section) and Marine Diffuser Location, which includes a broad interpretation of sediment habitat types recorded using seabed camera operations. Seabed photography and sample particle size analysis indicates that the sediments surrounding the proposed outfall pipeline route (marine section) were consistent with three main sediments types, namely a fine sand along the first 3.3km of the proposed outfall pipeline route (marine section), but with the presence of a coarser sub-cropping of sandy gravels in the central section of the route and sub-cropping of a fine sand veneer at the eastern end of the proposed outfall pipeline route (marine section) near the proposed marine diffuser location. Seabed sampling along the proposed outfall pipeline route (marine section) (Stations 3 to 7) all indicated a mean Wentworth classification of fine to very fine sand (mean particle size of 127 to 168 microns) but evidence from the seabed photography and processed biological grab samples indicated the presence of patchy exposures of coarser sediments, including some cobbles, near the shelf break, approximately 1.7km west of the proposed marine diffuser. This continued east to the proposed marine diffuser location but eventually sub-cropped a veneer of mobile fine sands. Of the nearby stations sampled, stations 10 and 11 both indicated mixed gravelly sands, whilst Stations 6 and 7 (located at the proposed marine diffuser location) indicated only a fine surface layer of sands over a mixed gravelly seabed in 2012, but more exposed gravels in 2017 (Figure 9.3 Sediment Changes Near the Proposed Outfall Pipeline Route (Marine Section) and Marine Diffuser Location and Photo 9.1). This highlights the mobility of surface sediments immediately surrounding the proposed marine diffuser location.

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2012 2017

Photo 9.1: Seabed at the Proposed Marine Diffuser Location Showing Rippled Sands in 2012, but Mixed Silty Sandy Gravels in 2017 The shallow geology of the proposed outfall pipeline route (marine section) was surveyed using sub-bottom profilers, boreholes and vibrocores (Causeway Geotech 2016). Evidence of the deeper geology recorded close to the shelf break north-west of Ireland’s Eye indicated dense very sandy, fine to coarse gravels at the surface and down to a depth of 6.20m. Vibrocores along the length of the proposed outfall pipeline route (marine section) failed to penetrate the seabed east of this location due to these gravels. However, shallow sub-surface sediments west of this site indicated consistent sediments to a depth of 80cm to 120cm to those recorded at the surface, albeit with slightly reduced fines at two of the stations. Beyond the immediate area surrounding the proposed outfall pipeline route (marine section), the seabed sediments indicated a generally sandy environment north of the proposed marine diffuser until Lambay Island, where sporadic bedrock exposures and larger areas of mixed gravelly sands (east of Lambay Island) are recorded. One station (Station 24) indicated the presence of a cobble field 2km east of the beach at Balcarrick. South of the proposed outfall pipeline route (marine section), the island of Ireland’s Eye is surrounded by exposed bedrock and sublittoral reefs, with generally mixed sediment of hard ground separating the island from the mainland, at Howth. This area was surveyed and is described separately in Section 9.3.4. Established gravel areas, cobble pavements and larger rocky areas were recorded using seabed photography and will provide a notably different habitat to that recorded at the proposed marine diffuser location and along the proposed outfall pipeline route (marine section). Here, an epifaunal component using the hard surfaces has become established, with this biological component described in greater detail below. Both intertidal and subtidal rocky reef complexes are recorded on the northern and eastern shorelines of Ireland’s Eye, south of the proposed marine diffuser location. These are classified as exposed to moderately exposed intertidal reefs and a subtidal range of flat and sloping bedrock, boulders, a mosaic of cobbles and vertical rock walls, many showing sediment scouring and occasionally a thin veneer of silt. The Ireland’s Eye reef complexes are listed as a qualifying interest (Reef habitat 1170) in the Rockabill to Dalkey Island SAC (Site Code: 003000).

9.3.3 Sediment Chemistry Details of sediment chemistry levels were recorded along the proposed outfall pipeline route (marine section) from surface sediments in 2012 and 2013 and from sub-surface vibrocores (to approximately 80cm to 120cm) in 2015. Changes to the levels of chemistry within the sediments are not expected to have altered significantly since these surveys due to the absence of any industrial activities near the site. A standard array of tests was

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carried out based on the array of naturally occurring and potentially anthropogenic contaminants. Results of detectable components are summarised in Table 9.8. For heavy and trace metals, elements of the greater potential for toxicity have been compared with Ecotoxicological Assessment Criteria (EAC) proposed by OSPAR (1997). EACs are defined as concentration levels of a substance above which concern is indicated. Table 9.8 shows a summary of metal results for sites surveyed during the marine surveys. These have been compared with the EAC limits where relevant. For the proposed outfall pipeline route (marine section), all metals were recorded in low concentrations below or between the two OSPAR EAC limits. Exceptions to this were recorded during the surveys but outside the area of the proposed outfall pipeline route (marine section). These were for arsenic within Dublin Bay, which recorded a slightly elevated concentration of 20.3 milligrams / kilogram (mg/kg), and for cadmium at a station north of Rush harbour, with a 1.2mg/kg level recorded. Overall, there appears to be no significant pattern of distribution, with the levels of metals remaining relatively consistent across the survey area with variations generally limited to sediment changes (i.e. the proportion of finer sediments) rather than from contamination sources. Comparisons with sub-surface sediments taken using the vibrocorer show that buried sediments within the dredge depth indicate similar or slightly lower levels of most metals. Other chemical indicators tested for during the marine survey were organotins (dibutyltin and tributyltin) and polychlorinated biphenyls (PCBs). The level of tributyltin was below detectable limits at all stations surveyed. This pollutant is of great environmental interest because it directly enters the aquatic ecosystems due to industrial application of organotin biocides and because of its high toxicity to non-target aqueous organisms (Horiguchi et al. 1997). Of far less toxicity is dibutyltin which is used as a stabiliser in plastics. Although this can have detrimental effects in higher concentrations (Bulten and Meinema 1991), it is generally found in low concentrations in coastal areas and can accumulate in the tissues of marine organisms such as fish (Kannan et al. 1996). Similar tests in buried sediments indicated undetectable concentrations of both compounds. Sediments were also tested for seven congeners of PCBs which were widely used as dielectric and coolant fluids in transformers, capacitors, and electric motors. PCBs remained undetectable during all surveys. Due to their environmental toxicity and classification as a persistent organic pollutant, the production of PCBs was banned in the United States in 1979 and by the Stockholm Convention on Persistent Organic Pollutants in 2001 (Porta and Zumeta 2002). For organic chemistry, the concentrations of TPH in the surface sediments were detectable in most surface samples analysed, ranging from below 10mg/kg to 29mg/kg (refer to Table 9.8). Analysis of material below the surface indicated undetectable concentrations below 10mg/kg. All sediments sampled fell below the level of 100mg/kg, an action level for possible harmful environmental effects used by regulatory authorities in the UK (i.e. Cefas). Aromatic compounds were also tested. These were split into BTEX and two- to six-ring polycyclic aromatic hydrocarbon compounds (PAHs). BTEX is an acronym that stands for ‘benzene, toluene, ethylbenzene and xylenes’, and was undetectable in all samples. These compounds are some of the more volatile organic compounds found in petroleum derivatives such as petrol and can contaminate river and marine sediments near urban centres. Toluene, ethylbenzene and xylenes have harmful effects on the central nervous system and can accumulate in the tissues of some marine life.

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Table 9.8: Summary of Sediment Chemistry (Surface Grab Samples 2012 and 2013, Subsurface Vibrocore Samples 2015)

Parameter Unit 2012 Survey (Four Sites) 2013 Survey (Eight Sites) 2015 Survey (Six Sites) 0.8m to 1.2m Ecotoxicological Assessment depth Criteria

Range Mean Range Mean Range Mean Lower Limit Upper Limit

Arsenic mg/kg 4.5–6.3 5.2 4.1–7 5.8 4.73–6.66 5.9 1 10 Copper mg/kg 11.1–14 12.9 9.2–14.5 11.7 3.76–5.79 4.3 5 50 Lead mg/kg 11.7–17.1 14.0 11.8–20.2 15.4 7.95–14.2 9.8 5 50 Tin mg/kg 1.2–3.6 2.3 1.3–3.5 2.2 - - - - Aluminium g/kg 14.6–19.1 17.0 15.2–21.4 18.4 14.0–18.3 15.7 - - Barium mg/kg 149–178 161.8 143–177 158.4 - - - - Iron g/kg 9.0–14.2 11.8 1.5–14,400 10.4 - - - - Cadmium mg/kg 0.2–1 0.5 0–0.6 0.3 0.11–0.17 0.1 0.1 1 Chromium mg/kg 27.4–37.2 32.1 23.4–36.5 29.8 27.2–44.2 33.3 10 100 Nickel mg/kg 8.7–14.1 11.0 9–17.6 12.0 7.4–11.1 9.4 5 50 Vanadium mg/kg 30.6–48.6 40.1 36.6–56.3 46.3 - - - - Zinc mg/kg 28.6–41.2 35.8 31.1–47.5 39.7 33.1–51.6 37.4 50 500 Mercury mg/kg 0.02–0.04 0.0 0.02–0.03 0.0 0.01–0.02 0.02 0.05 0.5 Dibutyltin µg/kg 24–160 76.3 20–110 67.1 <5 <5 - - Tributyltin µg/kg <5 <5 <20 <20 <2 <2 0.005 0.05 Total Hydrocarbons mg/kg 11–44 29.0 18–29 22.3 <10 <10 - - PCB (7 congeners) µg/kg <5 <5 <5 <5 <0.2 <0.2 1 10 Toluene µg/kg <5 <5 <5 <5 - - - - Benzene µg/kg <1 <1 <1 <1 - - - - Ethylbenzene µg/kg <2 <2 <2 <2 - - - - Xylenes µg/kg <6 <6 <6 <6 - - - - m/p Xylenes µg/kg <4 <4 <4 <4 - - - - o Xylene µg/kg <2 <2 <2 <2 - - - -

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Parameter Unit 2012 Survey (Four Sites) 2013 Survey (Eight Sites) 2015 Survey (Six Sites) 0.8m to 1.2m Ecotoxicological Assessment depth Criteria

Range Mean Range Mean Range Mean Lower Limit Upper Limit

PAH 16 µg/kg <80 <80 <80 <80 4.2–14.3 7.4 50 500 USEPA/compound Total PAHs µg/kg <1.,280 <1,280 <1,280 <1,280 94–155 117

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Quantitative two- to six-ring PAHs were analysed at each station using Gas Chromatography-Mass Spectrometry. The PAHs listed under the United States Environmental Protection Agency (USEPA) for the 16 priority pollutants for air, water and sediment quality are summarised in Table 9.8. Results indicated undetectable total concentrations (<1.28mg/kg) at all sites and for all individually speciated PAH compounds (<0.08mg/kg). Sub- surface sediments were all tested in 2015 using a methodology producing a lower detection limit. This recorded the presence of individual PAHs at a low mean concentration of 7.4µg/kg and a total PAH concentration of 117µg/kg. PAHs and their alkyl derivatives have been recorded in a wide range of marine sediments (Laflamme and Hites 1978) with the majority of compounds produced from what is thought to be pyrolytic sources. These are the combustion of organic material such as forest fires (Youngblood and Blumer 1975) and the burning of fossil fuels. The resulting PAHs, rich in the heavier weight four- to six-ring aromatics, are normally transported to the sediments via atmospheric fallout or river runoff. Another PAH source is petroleum hydrocarbon, often associated with contamination from urban centres and shipping fuels. These are rich in the lighter, more volatile, two- and three-ring PAHs (naphthalenes, phenanthrene and anthracene) with their alkyl derivatives. The PAHs recorded during the vibrocoring survey indicated no petroleum influences and are therefore expected to reflect a ubiquitous mixed or pyrolytic origin. PAHs recorded by all surveys indicated natural low concentrations well below the level of environmental concern.

9.3.4 Marine Benthos Macroinvertebrate Community A macroinvertebrate analysis was carried out on replicates over a large area benthic programme with 24 stations surveyed in 2012 and a further eight stations repeated around the proposed outfall pipeline route (marine section) in 2013 and again in 2017 (Appendix A9.1). The survey was carried out during the summer months to convey a maximum population after the established annual recruitment by recently settled juveniles to adults. Sites represented the proposed outfall pipeline route (marine section), as well as sediment changes near the Proposed Project and within a full tidal excursion (or maximum distance travelled by surface water over a full tidal cycle) from the proposed marine diffuser location. Macrofaunal samples were processed in the field using a 500µm mesh size. For all three benthic survey campaigns, the macrofaunal taxonomy of all recovered fauna identified almost 16,000 individuals from the 63 grab samples analysed. A matrix of faunal data for each sample is listed in Appendix A9.1. For ease of presentation and comparison, the survey sites were rationalised to a dataset within close proximity of the proposed outfall pipeline route (marine section), a total of 57 samples. Here, over 11,000 individuals were recorded from 245 different species. Of the species recorded, 92 were classified as epifaunal in nature, with 199 infaunal species consisting of 67 annelids accounting for 47.5% of the total individuals. The molluscs were represented by 46 species (27.8% of individuals), the crustaceans by 52 species (but only 12.2% of individuals) whilst echinoderms were represented by 14 species (8.7% of individuals). All other groups (i.e. Turbellaria, Nematoda, Nemertea, Cnidaria, Chelicerata, Porifera and Chaetognatha) accounted for the remaining 3%, or 11 species. The population along the proposed outfall pipeline route (marine section) indicated a number of community changes relative to the change in sediment type, with sands providing the dominant habitat to the west, becoming mixed with gravelly muddy sands and sandy gravels dominating the seabed at the shelf break and towards the east. A distribution of these different taxa are presented for Station 4 (sands) to the west and Station 11 (gravelly muddy sands) to the east, in Diagram 9.1, with a separation of the data by survey year.

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Other species of interest in the area were recorded at Station 27, located south of Ireland’s Eye in 2012. This recorded a seed mussel bed (Modiolus modiolus), with very high numbers of recently settled individuals. Other mussel beds (in particular those of the blue mussel (Mytilus edulis)) have been recorded in areas to the west of Ireland’s Eye and can be considered a potentially sensitive habitat to impacts from smothering. When found in dense aggregations, this biotope creates an important biogenic reef habitat encouraging high biodiversity. These can be designated as an Annex I habitat under the Habitats Directive. No Annex I habitats were recorded within the proposed outfall pipeline route (marine section).

Station 4 (2017) Station 11 (2017)

Station 4 (2013) Station 11 (2013)

Station 4 (2012) Station 11 (2012)

Diagram 9.1: Macro-Invertebrate Distribution by Phylum (Stations 4 and 11, Between Surveys in 2012 and 2017) The benthic community recorded in this area was diverse and typical for a mixed inshore sediment environment, with both infaunal deposit feeders and surface living epifaunal species both well represented. When the surveys were combined, the overall population was dominated by polychaete worm (a segmented annelid), closely followed by the molluscs, in particular the bivalves. The molluscs represented four of the top 10 numerically

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dominant species present, whilst annelids (polychaete worms) were also represented by a further four species, whilst the remaining species were represented by a brittle star Amphiura filiformis and the crustacean Pseudocuma longirostris. Polychaetes were dominated by Capitomastus minimus (particularly in 2017), Owenia fusiformis, Lagis koreni and Cirratulus cirratus, whilst the molluscs were Kurtiella bidentata, Fabulina fabula, Thracia phaseolina and Abra alba. When combined surveys were ordered into rank dominance, the main distribution of these species altered slightly, although seven of the top 10 numerically dominant species are included within the top 10 ranked species. Here, the mollusc F. fabula is the most consistent species with two other molluscs (A. alba, K. bidentata and T. phaseolina) recorded in the top six behind the polychaete C. minimus. This species community is very similar to communities recorded in the early 1970s (Walker and Rees 1980). A close resemblance to the shallow Venus or Boreal offshore sand association and the Boreal offshore muddy sand association (Jones 1950; Thorson 1957) indicates that a significant stability within the marine sediments has been maintained in this area over several decades. The primary and univariate parameters are listed for all stations in Appendix A9.1. The number of individuals recorded during this study was quite consistent within the survey area, although the medium sands of Station 1, in Dublin Bay, indicated a low number of both species and individuals in 2012. A median for the survey was 47 species and 1,860 individuals per square metre. The median diversity was at a moderate level overall (at 4.10), although this parameter varied by station, ranging from a low diversity of 2.92 recorded in Dublin Bay (Station 1 in 2012), to a very high diversity of 5.37 in the same year recorded on the mixed gravely sands at Station 10, due south of the proposed marine diffuser location. This reflects the varying sediments and biological niches available in these two quite different sediment types. Other indices (Pielou’s evenness and Margalef’s species richness) both indicated relatively low species dominance within the population and only slight variability, indicative of some community separation by some sites and between survey years. Overall, these stations reflect a relatively consistent community with a moderate diversity and abundance, but with a subtle change between 2012, 2013 and 2017. Benthic environments are naturally dynamic with the biological population constantly varying between years due to the different success rates by some species during larval recruitment. This affects the relative dominance of key species between survey years and would be expected to continue to change constantly in the survey area. The moderate diversity reflects a high number of species for the relatively high numbers of individuals overall, although the numbers of individuals varied between sites and slightly between years. The most dominant individual species by site was the polychaete C. minimus which had a mean abundance of 2,000 individuals per m2 (ind/m2), although this was recorded at maximum density of 2,300ind/m2 (for Station 11 in 2017). Only 16% of the 247 species recorded were represented, on average, by more than one specimen per grab sample (i.e. >10ind/m2), whilst 16% of species were represented by only a single specimen over all three surveys (a cumulative sample area of 5.7m2). A more thorough examination of the macrofaunal community was carried out using a multivariate analyses technique on the datasets from all three survey years. The results showed minor variations but with significant similarities in faunal compositions between the three survey years. However, the communities fundamentally remained the same throughout. Changes in the biological community from 2012 to 2013 were attributed to higher abundances of the more dominant species recorded in 2012. In 2017, the population altered further with a change in the top five species. The distribution of key phylogenetic groups between survey years is shown in Diagram 9.1. This separates the surveys into two stations, which represent sands to the west of the proposed outfall pipeline route (marine

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section) (Station 4) and muddy sandy gravels (Station 11) just north of the proposed marine diffuser location. Results show that, whilst some variations exist between survey years, shown above, the greatest variations in species richness between stations is predominantly a result in habitat change across the area. At both sites, annelids were the dominant fauna type followed by molluscs, crustaceans and then echinoderms, by both richness and abundance. The greater variation was recorded at Station 11, having a notably higher epifaunal component owing to the gravel substrate. Furthermore, the numbers of Crustacea appeared to fall in 2013, but recovered again in the later survey. Comparison of survey years showed that the richness of crustacea decreased significantly in 2013 for both sandy and gravelly substrates, whilst the richness of echinoderms dropped significantly in the sandy substrate but remained consistent on the coarser sediments over all three years. As all three surveys were conducted in the same season (summer), these observed inter-annual differences demonstrate the natural temporal shift in community structure with changes in the dominance of certain species. Multivariate analysis was also used to compare the distribution and repetition of biological communities by sediment type. The results indicated consistent clustering of sites into communities dominated by sediment types, despite the survey year in which the samples were acquired. Muddy sandy gravel, found at the proposed diffuser location, varied from the other sediment types due to higher counts of the brittlestar Amphiura filiformis and polychaete Scalibregma inflatum. Muddy sand was separated out due to relatively high counts of the polychaetes Lagis koreni and Owenia fusiformis. Stations with the sand classifications found predominantly along the shallower part of the proposed outfall pipeline route (marine section) differed due to lower species dominance but high numbers of the polychaete Magelona mirabilis. The edible mussel (Mytilus edulis) and swimming crab (Liocarcinus depurator) were responsible for most of the differences recorded in the maerl gravel found on the southern side of Ireland’s Eye, surveyed in 2012. Epifaunal Community Observations made during the taxonomy and via seabed photography have identified a significant epifaunal community within many of the stations surveyed, particularly those to the east of the proposed outfall pipeline route (marine section) relating to the coarser gravels. Taxonomic records showed that both solitary and colonial species of epifauna were recorded during the benthic survey, with as many as 23 different species recorded at Station 10, located within the mixed gravelly sediments. Diagram 9.2 shows the numbers of species recorded relative to the infaunal biology, with epifaunal species represented in all sites surveyed over the three periods.

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Diagram 9.2: Distribution of Epifaunal Species From all surveys, these samples recorded a large number of epifaunal species dominated by 24 species of bryozoan, 27 species of Cnideria, six species of sponge and an entroproct. One of the most dominant groups were bryozoans, with Conopeum reticulum the most common, but none were recorded in large numbers. Most of the bryozoans were upright branching or ‘turf’ forming species, e.g. Bugula spp., Crisia spp., Alcyonidium diaphanum, Flustra foliacea, Vesicularia spinosa and Scrupocellaria scruposa. The sponge fauna was relatively sparse. Cliona celata was found boring within shells, whilst Dysidea fragilis is a ubiquitous species around the Irish coast and can range from small crusts to large massive specimens. Scypha ciliata often settles on other epibenthic species, and none of the species were commonly found due to the generally sandy substrate at most sites sampled. The densest coverage by epifauna was by the hydroids, which were relatively well developed, especially Laomedea flexuosa and Sertularia cupressina which were recorded at over half of the sites. Some larger species, such as Hydrallmania falcata and Halecium spp., acted as settlement surface for smaller creeping species such as Campanularia hincksii and Clytia hemisphaerica. Many of the hydroids were heavily settled along with juvenile Mytilus and Modiolus mussels. Another species found present during the initial benthic survey was biogenic maerl sands in isolated patches at Station 27, south of Ireland’s Eye. This is coralline red algae which can create a diverse biological community at the seabed through sediment modification and habitat creation, although only isolated pockets of mostly dead debris were recorded during the survey using seabed photography at this station (in 2012). The presence of maerl has been previously recorded by the GSI as part of the INFOMAR project in this area of Dublin Bay. As this was on the opposite side of Ireland’s Eye to the proposed outfall pipeline route (marine section), this was not surveyed again in 2013 or 2017 (as no impacts are expected).

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In addition to coarse sediments recorded along the proposed outfall pipeline route (marine section) itself, the intertidal and subtidal reefs of the Ireland’s Eye SAC are recorded approximately 1.6km to the south. These features have been surveyed separately and are described in detail in the next Section. Littoral and Sublittoral Reefs Around Ireland’s Eye The conservation objectives of the Annex I Reefs (1170) of the Rockabill to Dalkey Island SAC are to maintain a favourable conservation status within the SAC. The NPWS has confirmed that the habitat is stable or increasing subject to natural processes and that the community structure of the intertidal and subtidal reef community complex is to be maintained as a conservation objective. The SAC is based on an estimated habitat area of 182ha using the 2010 and 2011 intertidal and subtidal reef survey data (MERC 2010; 2012a; 2012b), INFOMAR bathymetry and the Arklow to Skerries Islands Admiralty Chart (1468_0). Within the Rockabill to Dalkey Island SAC, the designations for intertidal and subtidal reefs were based on surveys undertaken in 2010 and 2011 (MERC 2010; 2012a; 2012b). These data were used to determine the physical and biological nature of the Annex I habitat, on all of the islands within the SAC. Estimated areas of each community type within the Annex I habitat were based on interpolations for the island of Ireland’s Eye. The development of a community complex target arises when an area possesses similar abiotic features but records a number of biological communities that are not regarded as being sufficiently stable and/or distinct temporally or spatially to become the focus of conservation efforts. In this case, examination of the available data from Rockabill to Dalkey Island SAC identified a number of biological communities whose species composition overlapped significantly. Such biological communities are grouped together into what experts consider are sufficiently stable units (i.e. a complex) for conservation targets.

S1 S2

L1

L2

Intertidal Survey (BSL 2015b) Sublittoral Dive Survey (BSL 2015b ) S3

L3

S4

Diagram 9.3: Ireland’s Eye Marine Community Types designated by Rockabill to Dalkey Island SAC

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Intertidal Reef Community Complex This reef community complex is recorded on the eastern and southern shores of Ireland’s Eye immediately south of the proposed outfall pipeline route (marine section) (including the proposed marine diffuser). The exposure regime of the complex ranges from exposed to moderately exposed reef for Ireland’s Eye. The substrate here is that of flat and sloping bedrock, cobbles and boulders. Vertical cliff faces are found on the north and north-east shores of the island. A detailed walkover survey was carried out in 2015 at three locations (see Diagram 9.3) along the eastern edge of the island, relating to the northern, central and southern extreme of the eastern shoreline (BSL 2015b). Survey operations were conducted in June/July 2015. Sites were selected from aerial photography to present different exposures and the vertical profiles completed along all of the lower, middle and upper shorelines at these locations. Each biological zone was photographed and surveyed. This survey has collected semi-quantitative data from two moderately exposed littoral stations (L1 and L3) and a sheltered station (L2). L1 was slightly modified by shading, wave surge and nitrogenous enrichment and the L3 upper shore biotope was similarly enriched by roosting seabirds. The positions of these sites are shown in Diagram 9.3. In the littoral zone, the biotopes ‘Corallina officinalis on exposed to moderately exposed lower eulittoral rock/Laminaria digitata on moderately exposed sublittoral fringe rock’ (LR.HLR.FR.Coff/IR.MIR.KR.Ldig) usually emerged from the sublittoral, followed by a zone covered by seaweeds to a faunally dominated shore consisting of limpets, barnacles and littorinids. The littoral zone was separated into vertical zones up the shoreline, with six bands recorded at L1 and L3 (exposed shorelines) and five at L2 (within a sheltered gulley) as described in Table 9.9.

Table 9.9: Summary of Intertidal Reef Community Complex

Littoral Site L1 L2 L3 General Gully sheltered by north-east stack. Sheltered inlet protected from wave South-east tip of the island partially description Typical exposed shore to wave action. separated from the main island by a action amplified by the effect of connecting intertidal reef surge through the gully. Shading with reduced algal component. Zone (i) Nitrate enriched LR.FLR.Lic.Pra A typical lichen zone dominated by the Nitrate enriched LR.FLR.Lic.Pra Prasiola supralittoral nitrophilous yellow lichen Xanthoria stipitata parietina and the green algae Prasiola stipitata LR.FLR.Lic.Pra Zone (ii) LR.HLR.MusB Limpets, barnacles and littorinids found Limpets and Semibalanus balanoides Upper shore amongst the algae spiral wrack and barnacles. LR.HLR.MusB channel wrack mixed to form an LR.MLR.BF.FspiB Zone (iii) Barnacles LR.HLR.MusB.Cht Ascophyllum nodosum and Fucus Patchy canopy of the bladderless Middle upper vesiculosus LR.LLR.F.Asc.FS ‘Bladder wrack’ Fucus vesiculosus. shore LR.HLR.MusB.Cht (barnacle zone) Zone (iv) Faunally dominated Typical Fucus serratus and red Faunally dominated LR.HLR.MusB.Sem Upper middle LR.HLR.MusB.Sem seaweeds LR.MLR.BF.Fser.R shore Zone (v) LR.HLR.FR.Mas Laminaria hyperborea forest (with Lower middle occasional L. hyperborea) with frequent shore patches of red algae dominated by coralline crusts. Fucus serratus, Osmundea pinnatifida and Mastocarpus stellatus LR.HLR.FR.Mas (v) Zone (vi) Algae dominated Algae dominated Algae dominated Lower shore LR.HLR.FR.Coff/IR.MIR.KR.Ldig LR.HLR.FR.Coff/IR.MIR.KR.Ldig LR.HLR.FR.Coff/IR.MIR.KR.Ldig

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An example summary of the vertical habitat changes recorded in the littoral zones is listed in Table 9.10. Overall, intertidal habitat indicated faunal populations that were well represented and moderately diverse habitats containing many of the common species found along the Irish Sea coastline.

Table 9.10: Summary of Intertidal Reef Community Complex (L3) (BSL 2015b)

Littoral Zonation Example Image South-east tip of the island partially separated from the main island by a connecting intertidal reef

Zone (i) Supralittoral upper shore

LR.FLR.Lic.Pra Prasiola stipitata on nitrate-enriched supralittoral or littoral fringe rock.

Zone (ii) Eulittoral upper shore

LR.HLR.MusB Mussel and/or barnacle communities.

Zone (iii) Eulittoral middle upper shore (barnacle zone)

LR.HLR.MusB.Cht Chthamalus spp. on exposed upper eulittoral rock. Patchy canopy of the bladderless ‘Bladder wrack’ Fucus vesiculosus.

Zone (iv) Eulittoral Upper middle shore

LR.HLR.MusB.Sem Semibalanus balanoides on exposed to moderately exposed or vertical sheltered eulittoral rock. Faunally dominated.

Zone (v) Eulittoral lower shore

LR.HLR.FR.Mas Mastocarpus stellatus and Chondrus crispus on very exposed to moderately exposed lower eulittoral rock. Fucus serratus, Osmundea pinnatifida and Mastocarpus stellatus.

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Littoral Zonation Example Image

Zone (vi) Sublittoral fringe

LR.HLR.FR.Coff/IR.MIR.KR.Ldig Corallina officinalis on exposed to moderately exposed lower eulittoral rock/Laminaria digitata on moderately exposed sublittoral fringe bedrock.

Algae dominated Laminaria digitata forest (with occasional L. hyperborea) with frequent patches of red algae dominated by coralline crusts.

Subtidal Reef Community Complex This reef community complex is recorded off the northern, eastern and southern shores of Ireland’s Eye immediately south of the proposed outfall pipeline route (marine section) and the proposed marine diffuser location. The substrate ranges from that of flat and sloping bedrock, to bedrock with boulders and also a mosaic of cobbles and boulders. Vertical rock walls occur on the north and east of Ireland’s Eye, whilst the northern reaches of the island show both sediment scouring and a thin veneer of silt covering the reef. In general, previous surveys (MERC 2010; 2012a; 2012b) noted that where the reef was subjected to the effects of sediment, either through scouring or settlement of silt, low numbers of species and individuals occurred, although these observations were based on extremely limited site investigation works with only a couple of drop-down video sites acquired. As with the intertidal surveys noted above, a detailed assessment of the subtidal reefs was carried out in 2015, although this operation was carried out in two separate phases. In May 2015, Ireland’s Eye was surveyed at nine locations using a specialist drop-down camera system (BSL 2015a). The positions of these sites are shown in Diagram 9.3. This survey infilled some missing bathymetry close to Ireland’s Eye cliffs and provided targeting information for representative areas for a second, more detailed, survey. This more detailed assessment was carried out using a scientific dive team at four locations on the northern and eastern sides of the island in June/July 2015 (BSL 2015b). Sites were selected using the earlier video system looking for representative examples based on transects at the base of the reef structure up to the eulittoral zone. Each biological zone was photographed and surveyed. The floral and faunal taxa were identified and abundance scale values allocated using the SACFOR protocol on all the conspicuous species in each biotope encountered. As recorded by the earlier MERC projects, the sublittoral reefs were all found to be heavily silted, but were moderately diverse. This survey collected semi-quantitative data from four dive locations, with two sites located beneath the steep cliff face of the northern coast (S1 and S2), and two located adjacent to the rocky shorelines in the south-east of the island (S3 and S4). The sublittoral stations were characterised by Laminaria digitata forests in the shallower part (IR.MIR.KR.Ldig.Ldig) and were usually replaced by the biotope ‘Foliose red seaweeds with dense Dictyota dichotoma and/or Dictyopteris membranacea on exposed lower infralittoral rock’ (IR.HIR.KFaR.FoR.Dic). The deeper extent was dominated by a ‘Mixed turf of bryozoans and erect sponges with Sagartia elegans on tide- swept circalittoral rock’ (CR.HCR.XFa.ByErSp.Sag) or, in the case of Sublittoral S2, ‘Flustra foliacea and colonial ascidians on tide-swept moderately wave-exposed circalittoral rock’ (CR.HCR.XFa.FluCoAs). The deeper biotope at Sublittoral S4 was categorised as a possible ‘Polyclinum aurantium and Flustra foliacea on sand scoured tide- swept moderately wave-exposed circalittoral rock’ (HCR.XFa.FluCoAs.Paur), probably due to the increased sedimentation noted at these stations. The maximum depths surveyed for each site was between 10.5m and 14m below mean sea level. An example summary of the vertical habitat changes recorded in the sublittoral zones is listed in Table 9.11.

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Table 9.11: Summary of Subtidal Reef Community Complex (S2) (BSL 2015b)

Sublittoral Zonation Example Image These stations were situated along the north coast of the island and showed significant evidence of a heavy silt burden. The deeper sediment plains gave way to a steeply inclined reef at a depth of approximately 15.5m Ordnance Datum Malin (ODM). The reef was initially broken, with deposits of muddy gravel lying between boulders and outcrops of sloping bedrock.

Zone (i) Infralittoral upper shore

IR.MIR.KR.Ldig.Ldig Laminaria digitata on moderately exposed sublittoral fringe bedrock Stunted Laminaria digitata kelp plants, with several other foliose red algae, such as Palmaria palmata and Delesseria sanguinea. Beneath these algae, crusts of mussels and barnacles predated by the common starfish Asterias rubens.

Zone (ii) Infralittoral rock approx. 6m to 8.5m

IR.HIR.KFaR.FoR.Dic Foliose red seaweeds with dense Dictyota dichotoma and/or Dictyopteris membranacea on exposed lower infralittoral rock

Algal species were Rhodymenia holmesii, Sphondylothamnion multifidum and Apoglossum ruscifolium amongst the sward. Fish observed were ling (Molva molva), the black goby (Gobius niger) and greater pipefish (Syngnathus acus).

Zone (iii) Circalittoral ca. 10-15.5 m

CR.HCR.XFa.FluCoAs Flustra foliacea and colonial ascidians on tide-swept moderately wave-exposed circalittoral rock. The biotope on these outcrops was dominated by the bryozoans Flustra foliacea, Scrupocellaria sp. and Bugula flabellata

CR.HCR.XFa.ByErSp.Sag Mixed turf of bryozoans and erect sponges with Sagartia elegans on tide- swept circalittoral rock

Other sub-dominant taxa were feather- star Antedon bifida; plumose anemone Metridium dianthus and Sagartia elegans and Urticina feline; barnacle Balanus crenatus; soft coral Alcyonium digitatum; frequent erect sponges Hymeniacidon perlevis, Amphilectus fucorum and Haliclona simulans; the hydroids Nemertesia antennina and Obelia dichotoma; as well as the tunicate Clavelina lepadiformis. Univariate analyses showed clear differences between the littoral and sublittoral stations in terms of species richness, with twice as many species recorded from the sublittoral area (88.3±19.2SD as opposed to 44.7±11.6SD). Both littoral and sublittoral environments indicated moderately high species diversity. Multivariate

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analyses revealed statistical separation of biotopes with the vertical zonation of the fauna (by water depth or height on the foreshore) constituting the dominant community patterns observed. A comparison of the species composition for both littoral and sublittoral stations around Ireland’s Eye indicates the consistency of the flora and fauna at the different survey sites (Diagram 9.4).

100%

90% Tracheophyta 80% Ascomycota Chlorophyta 70% Ochrophyta 60% Rhodophyta Chordata 50% Echinodermata 40% Bryozoa Mollusca 30% Arthropoda 20% Annelida Nemertea 10% Cnidaria 0% Porifera L1 L2 L3 S1 S2 S3 S4 Littoral Station Sublittoral Station

Diagram 9.4: Distribution of Species per Phyla and Station on Ireland’s Eye (BSL 2015b) No species of particular nature conservation interest were noted during any of the surveys and no rare or particularly fragile biotopes were recorded. However, natural siltation levels were high in the sublittoral environment, a fact that has not appeared to have had a significant impact on the biological diversity in this area.

9.3.5 Water Quality Profiling, Sampling and Plankton Water Quality Profiling (Vertical Profile) A detailed discussion on water quality for the area, along with the impact from the Proposed Project, is covered in Chapter 8 Marine Water Quality. A summary of key water quality aspects has, however, been discussed below to place this into the context of the marine ecology and the parameters recorded during the benthic surveys. The status of coastal waters is assessed using the EPA Trophic Status Assessment Scheme. This assessment is required for Council Directive 91/271/EEC of 21 May 1991 concerning urban wastewater treatment (Urban Waste Water Treatment Directive) and Council Directive 91/676/EEC of 12 December 1991 concerning the protection of waters against pollution caused by nitrates from agricultural sources (Nitrates Directive). The scheme compares the compliance of individual parameters against a set of criteria indicative of trophic status. Currently, the EPA reports that the north-western Irish Sea and Dublin Bay (HA 09) are unpolluted whilst Malahide Bay has a potentially eutrophic status based from 2007–2012 monitoring. Potentially eutrophic water bodies are those in which criteria in two of the categories are breached and the third falls within 15% of the relevant threshold value. Rogerstown and Baldoyle estuaries were both categorised as eutrophic between 2010 and 2012. Whilst Baldoyle was not surveyed between 2007 and 2009, Rogerstown was recorded as intermediate during the earlier surveys

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and has shown a slight deterioration. Malahide Bay has improved in water quality from potentially eutrophic to unpolluted since an earlier failure to comply with the environmental quality standard for dissolved inorganic nitrogen (DIN). Previously, the deterioration in status in Malahide Bay was due to the presence of green opportunistic macroalgae, which were previously observed in these areas during earlier assessments but had not been formally assessed (EPA 2010). In addition to nutrient enrichment, other pressures such as hazardous substances and morphological alterations can also impact on the quality of aquatic systems (EPA 2015). Under Directive 2000/60/EC of 23 October 2000 of the European Parliament and of the Council establishing a framework for the Community action in the field of water policy (Water Framework Directive), these additional pressures, along with nutrient enrichment, must be addressed. In the Directive, biological indicators are used to assess the ecological status of transitional and coastal waters. Classification schemes have been developed that use the characteristics of different biological communities, together with information on the physico-chemical environment to define ecological status. According to the EPA’s (2017) Water Quality in Ireland, the ecological status of the transitional waters of the north-western Irish Sea is good and Malahide Bay moderate, whilst the proposed outfall pipeline route (marine section) location is classified as undetermined (but previously recorded as good (EPA 2015)). Ecological status is assessed on a ‘one-out-all-out’ basis. Overall ecological status of a water body is based on the biological quality element or physico-chemical standard with the lowest status. For example, if all the elements in a particular water body are at or near reference conditions, then the status of the water body is considered to be high. However, if any single biological quality element or chemical parameter is of lesser status, then classification is based on that element. Malahide Bay was one of 102 transitional and coastal areas assessed by the EPA, Marine Institute and IFI between 2007 and 2012 for Water Framework Directive status classification, using the biological quality and physico-chemical elements listed above. Water quality measurements were undertaken at four locations within the bay as part of the benthic survey operations in the summer of 2012 and repeated again in the winter of the same year. Further sampling was carried out at the proposed outfall in 2017. The position of these sites is shown in Figure 9.1 Summary of Field Survey Operations for the Proposed Outfall Pipeline Route (Marine Section). A summary of the profiled results is outlined in Table 9.12. Four locations were chosen for profiling deployments within the regional survey area, namely the proposed marine diffuser location (Station 7), the offshore reference (Station 1), the southern extremes based on a full tidal excursion from the proposed outfall pipeline route (marine section) location and a site located at the mouth of Malahide Estuary (Station 24). The proposed outfall pipeline route (marine section) was sampled twice in each seasonal period with a separation of approximately six hours between deployments so as to sample different tidal states. Overall, data showed very little variation between sites. Most data extremes were recorded at the reference location 11km offshore from the mainland (4km from Lambay Island) and in approximately 35m of water. These data showed that a small thermocline of approximately 1.5°C and around 15m depth was apparent at this site: warmer during the summer, cooler during winter. There was also a corresponding increase in salinity with depth at the same point. Water quality at the proposed marine diffuser location was repeated for high and low water tide periods in 2017.

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Table 9.12: Water Profiling Results Summer and Winter (2012 and 2017) (Red Denotes Highest Value, Whilst Blue Denotes the Lowest)

Summer (2 August to Temp (°C) Salinity (PSU) Turbidity (NTU) pH O² (%Sat) 5 August 2012)

Location Tide Min Max Min Max Min Max Min Max Min Max (HW) ENV_007 +1.5hrs 14.88 14.98 33.96 33.98 -0.1 2.1 8.05 8.07 99.1 101.4

ENV_007 +6.5hrs 14.88 15.01 33.93 33.96 -0.1 0.2 8 8.01 99.7 101.4

ENV_001 +5hrs 15.09 15.15 33.92 33.96 0.1 5 8.02 8.03 98.7 100.5

ENV_024 -4hrs 15.15 15.16 33.81 33.83 2 4.3 8.05 8.05 98.1 98.9

REF_001 +1.75hr 13.87 15.27 33.97 34.34 -0.4 3.5 7.95 8.02 97.5 104.2 s Mean 14.8 15.1 33.9 34.0 0.3 3.0 8.0 8.0 98.6 101.3

Winter (11 December Temp (°C) Salinity (PSU) Turbidity (NTU) pH O² (%Sat) 2012)

Location Tide Min Max Min Max Min Max Min Max Min Max (HW)

ENV_007 HW 7.59 7.61 34.52 34.55 2 8.3 7.88 7.89 99.1 102.8

ENV_007 +7hrs 7.29 7.34 34.51 34.54 2.6 10.3 7.96 7.98 98.5 102.4

ENV_001 -1hr 7.69 7.72 34.23 34.27 2.2 7.2 7.70 7.82 99.1 103.7

ENV_024 +6hrs 6.73 7.4 34.04 34.5 2.0 3.0 7.95 7.98 99.4 102.2

REF_001 +2.5hrs 7.74 9.14 34.53 35.07 -0.6 0.1 7.95 7.98 98.6 103.5

Mean 7.41 7.84 34.37 34.59 1.64 5.78 7.89 7.93 98.94 102.9

Summer (9 August Temp (°C) Salinity (PSU) Turbidity (NTU) pH O² (%Sat) 2017)

Location Tide Min Max Min Max Min Max Min Max Min Max (HW) ENV_007 HW 15.28 15.46 34.25 34.32 0.0 2.6 7.09 7.22 99.0 101.9

ENV_007 LW 14.41 15.01 34.28 34.41 0.0 1.3 7.06 7.28 97.7 99.7

Mean 14.85 15.24 34.27 34.37 0 1.95 7.075 7.25 98.35 100.8

Water Quality Sampling In addition to water quality profiling, discrete samples of water were sampled at three depths and at two locations at the proposed marine diffuser and a control site east of Lambay Island in 2012 and again over the proposed marine diffuser location in 2017. These were analysed for the range of parameters, including nutrients, heavy metals and hydrocarbons and are summarised in Table 9.13. Results showed that a number of parameters were undetectable within the samples, including the metals cadmium, mercury and barium, the nutrients nitrite and phosphorus, TPH or chlorophyll A. For the remainder of

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the results, total and dissolved organic carbons (TOC and DOC) recorded significantly higher concentrations in the summer, whilst the reverse was recorded for total silicon and nitrates. Metals indicated no pattern of distribution, although an inexplicably high concentration was recorded for chromium and nickel at the reference stations for the summer sample at 20m.

Table 9.13: Water Quality Variations in 2012 and 2017(µg/l)

Station Ref1 (2012) Station 7 (2012) Station 7 (2017)

Depth (m) 0 20 40 1 7 20 1 7 20 Ni (Total) 2–3 4–58 3 3 2–3 3 - - - Cr (Total) <1–1 <1–153 <1–1 1 1 1 - - - Cd (Total) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 - - - Cu (Total) 4 5–8 5-6 6–7 5 5–7 - - - Pb (Total) <1 <1 <1–2 <1–1 <1 <1 - - - Zn (Total) 9 10–16 11–13 18–19 11–12 11–13 - - - As (Total) 10–17 11–26 12–28 <0.112 12 11–18 - - - Hg (Total) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 - - - Ba (Total) <10 <10 <10 <10–10 <10 <10 - - - *SO4 (Dissolved) 2,840– 2,910– 2,990– 2,760– 2,740– 2,720– 2,170– 2,190– 2,080– 3,100 3,250 3,250 2,770 2,990 2,820 2,500 2,550 2,160 Nitrite as N <10 <10 <10 <10 <10 <10 <10 <10 <10 Nitrate as N 300–400 <200– <200 <200– <200–200 <200 <200 <200 <200 400 200 Si (Total) 100–600 <100– 300–400 200–600 200–800 300–900 - - - 400 Phosphorus <100 <100 <100 <100 <100 <100 <10–10 <10–10 <10 TOC 200–580 <200– <200–520 <200– <200–540 <200– <200 <200– <200 540 530 610 220 TPH Gas <10 <10 <10 <10 <10–10 <10 - - - Chromotography DOC 290–520 240–530 220–500 230–520 250–500 220–450 Chlorophyll A <10 - - <10 - - <10 <10 <10 *milligrams/litre (mg/l) Zooplankton Semi-quantitative samples of large zooplankton were taken during the benthic sampling campaign in 2012, both summer and winter (>250µm) and again in 2017 over high and low water periods. Samples were acquired using a vertical tow technique where a trawl net is hauled vertically from the seabed to the surface and the complete water sample rinsed and fixed in 4% formalin prior to the taxonomy and enumeration in the laboratory. Samples here were processed at Plymouth Marine Laboratory. The results are given in Appendix A9.1. Sample results showed the presence of zooplankton all year round, although the major contributors (such as the decapods and copepods) were more abundant in the summer months. The reference station indicated much greater numbers in the summer (at 681 individuals per m3) than recorded at the proposed outfall pipeline route (marine section) location (maximum of 57ind/m3 in the summer and 99.8ind/m3 in the winter 2012). This is interpreted as a result of the deeper water-depth recorded at the reference site, with the majority of zooplankton species recorded in deeper waters during daylight hours where they are less prone to predation. Data from 2017 at the proposed marine diffuser location indicated a higher abundance than the same site in 2012, increasing from

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365 to 408ind/m3 between high and low water periods. The most dominant species were consistently the copepods Acartia clausi, Centropages hamatus and Temora longicornis between survey years, although up to 27 different species were recorded in each of the samples overall.

9.3.6 Baldoyle Estuary Walkover Previous Survey Data Fingal County Council commissioned a survey of coastal habitats in the county in 2004 (Ecoserve 2005). Phase I of the study involved the mapping of all coastal habitats within the county. Phase II of the survey involved a study of the coastal vegetation communities within the county boundaries. Rare, threatened or legally protected flora were also recorded. The Baldoyle Estuary was surveyed as part of the Portmarnock area. The Baldoyle Estuary was further surveyed over several days in June 2006 as part of a national saltmarsh monitoring project commissioned by NPWS. The survey developed a monitoring methodology based on the Joint Nature Conservation Committee guidelines for saltmarshes, which was based on vegetation surveys and assessments of threats and management practices and adapted for Irish saltmarsh habitats. A detailed habitat map for the site and descriptions of the Annex I habitats present were outlined in the NPWS Saltmarsh Monitoring Project report (McCorry and Ryle 2009). The habitat map showing the distribution and extent of Annex I habitats produced are presented below in Diagram 9.5.

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Diagram 9.5: Habitat Map of the Annex I Habitats of Baldoyle Estuary Prepared by McCorry and Ryle (2009). The full descriptions for these Annex I habitats within the site, described by McCorry and Ryle along with the earlier worked commissioned by Fingal County Council in 2004, are outlined in Appendix A9.1. Overall, the site was deemed by McCorry and Ryle to be in favourable conservation status. The site was further visited in November 2013 and the habitat mapping and descriptions prepared by McCorry and Ryle (2009) were reviewed in the field in relation to the current conditions at the site and the proposed outfall pipeline route (marine section). The GIS shapefiles prepared by McCorry and Ryle (2009) were used in the field in conjunction with aerial photographs. This allowed for an accurate assessment in the field of the extent of habitat types as previously described and mapped and to document any changes in them. A photographic record of the habitats recorded was also made and geo-tagged. A selection of site photographs is presented in Appendix A9.1. Proposed Outfall Pipeline Route (Marine Section) – Eastern Side The eastern section of the proposed outfall pipeline route (marine section) crosses an area of the estuary near the public car park for the Portmarnock Beach and dune system/entrance to Portmarnock Golf Club. At this side of the estuary, the proposed outfall pipeline route (marine section) crosses a grassy embankment, which is mown and maintained by Fingal County Council, adjoining the public road, before reaching a band 20m to 30m wide in

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places of a mosaic of Atlantic salt meadows and Mediterranean salt meadows. To the north of the proposed outfall pipeline route (marine section) is an area of Atlantic salt meadow. These areas grade into extensive swards of Spartina, which extend towards the centre of the estuary where they become broken up and form a mosaic of clumps of Spartina and mudflats. At the upper extent of the saltmarsh, the vegetation is dominated by creeping bent grass (Agrostis stolonifera), with occasional sea beet (Beta maritima), sea rush (Juncus maritimus), red fescue (Festuca rubra), sea purslane (Halimione portulacoides), common scurvy grass (Cochlearia officinalis) and sea pink (Armeria maritima). These grade into an area of middle marsh with occasional pans and creeks which are dominated by sea pink, sea plantain (Plantago maritima), lax-flowered sea lavender (Limonium humile) and sea aster (Aster tripolium) with occasional stands of saltmeadow rush (Juncus gerardii) and sea rush, whilst areas with higher inundation of the tide (lower marsh) contain sea arrow grass (Triglochin maritima), common scurvy grass and sea purslane. This then grades into areas of dense stands of common cordgrass (Spartina anglica) which dominate the mudflats and creeks with occasional Enteromorpha. North of the main crossing point for the proposed outfall pipeline route (marine section) is an area with better defined pans and creeks that more closely approximates pure Atlantic salt meadows, and a stand of common reed (Phragmites australis) is present near where the road turns back to the west. Proposed Outfall Pipeline Route (Marine Section) – Western Side The western section of the proposed outfall pipeline route (marine section) crosses an area of the estuary near the Mayne River. The western side contains a much narrower band of saltmarsh vegetation, which is backed by an area of rank grassland adjoining the road. Species recorded here include creeping bent, thistles (Cirsium arvense and Cirsium vulgaris), docks (Rumex sp.), tall fescue (Festuca arundinacea), bush vetch (Vicia sepium), nettle (Urtica dioica) and common comfrey (Symphytum officinale). Below this is a narrow band of a mosaic of Atlantic salt meadows and Mediterranean salt meadows, which is no more than 1m to 4m wide. The main species recorded here include sea beet, sea purslane and sea arrowgrass interspersed with stands of common cordgrass. These become more dominant, forming a Spartina sward for approximately 30m to 40m before breaking up into a mosaic of clumps of Spartina and open mudflats. The band of saltmarsh vegetation tapers off to the south towards the Mayne River, and occasional sparse patches of sea aster, common scurvy grass, glasswort (Salicornia sp.) and common cordgrass are present on the open muds. Backing this is a stone wall with scattered sea aster, lax-flowered sea lavender, sea arrowgrass and sea beet. Overall, the habitats at Baldoyle Estuary do not appear to have undergone any significant changes in quality or extent at the proposed outfall pipeline route (marine section) since the 2006 surveys conducted by NPWS. The boundaries of the Annex I habitats as mapped by McCorry and Ryle have not changed significantly since that time, and the vegetation composition at the proposed outfall pipeline route (marine section) appears to have remained broadly similar. Some of the species recorded in the earlier 2004 surveys by Doogue et al., such as Atriplex portulacoides, Juncus gerardii and Oenanthe lachenalii, were not encountered along the proposed outfall pipeline route (marine section) but may be present further north within the estuary where a greater extent of saltmarsh vegetation is present.

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9.3.7 Marine Mammals The IWDG operates an all-Ireland database of casual cetacean sightings (IWDG 2011a) and strandings. Since 2001, regular monthly effort-related surveys from land based stations have been included in the IWDG database. All records are validated and available on www.iwdg.ie. Whilst there have been very occasional records of either large baleen cetacean species, such as the humpback (Megaptera novaeangliae) and fin whales (Balaenoptera physalus), as well as the orca toothed whale (Odontoceti; Orcinus orca), in the Dublin inshore area, these larger whales are rare. A review of the IWDG casual sightings database, showing over 1,400 records over the past 15 years, has revealed that only two species of cetacean are likely to occur within the proposed outfall pipeline route (marine section) on a regular basis and all year round. These are the harbour porpoise (Phocoena phocoena) and the bottlenose dolphin (Tursiops truncatus) representing 71% and 15.4% of all cetacean sightings recorded, respectively. This equates to a mean monthly observation of approximately 10 casual sightings (30 individuals), for the harbour porpoise or eight sightings (22 individuals) for the bottlenose dolphin. Other rare but regular species recorded in the area are the minke whale (Balaenoptera acutorostrata), equivalent to around five observations per year, and the common dolphin (Delphinus delphis), equivalent to at least one observation per year. However, as approximately 6.5% of all database sightings included unidentified cetacean species, further species or increased frequency of these identified species are expected to be greater than recorded here. A summary of the possible cetaceans expected to be present within the area of the Proposed Project is listed in Table 9.14.

Table 9.14: Cetacean observations in the Dublin Geographical Area (IWDG 1970-2013)

Species Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Ireland’s only common porpoise species, the harbour porpoise is frequently recorded around the entire Irish coast. There are many locations where they can be observed all year round in the Dublin geographical area (constituted Harbour porpoise 71% of all cetacean sightings for this area on the IWDG database). They are most commonly sighted from June through to the autumn/winter, but reduced encounter rates from well-watched sites suggest they move offshore in spring between March and June for calving/breeding. They breed in Irish waters.

Found in all Irish coastal waters and the second most frequently recorded dolphin species in Ireland, but the most common dolphin recorded in the Dublin geographical area, constituting 15.5% of cetacean observations. Peak Bottlenose dolphin occurrences were in June and December. They occur inshore around all Irish coasts with semi-resident groups historically reported in the south and south-west. They also occur offshore in the Celtic Sea and in the Irish Sea. They are present year round and breed in Irish waters. Inshore and offshore ecotypes may exist.

Present in the Celtic and Irish Sea, predominantly in the summer and early autumn (Reid et al. 2003). The most frequently recorded dolphin species in Irish waters overall but uncommon in the Dublin geographical area, recording Common dolphin only 0.9% of all cetacean sightings on the IWDG database. Typically recorded in mixed group sizes in the summer months, equivalent to a few sightings each year. Most abundant on the continental shelf and breeding along the south and south-west coasts of Ireland.

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Species Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

This is a continental shelf species which appears to prefer deep offshore waters but on occasion can be seen regularly close inshore around the Irish coast. Sightings and strandings concentrated on the west and south-west Risso’s dolphin coast and occasional sightings in the Irish Sea. Previously sighted only twice in the Dublin geographical area on the IWDG database. They are found year round in Irish waters, perhaps moving inshore in the summer months. Breeds in Irish waters.

This is a continental shelf species which can be recorded briefly in travelling groups in shallow inshore waters off all Orca whale coasts and in the Irish Sea. The IWDG database has recorded four sightings for Dublin geographical area. Observed inshore sightings tend to increase during late summer and autumn (Berrow et al. 2010).

The minke whale is the most common baleen whale recorded in the Dublin geographical area, corresponding to Minke whale 3.9% of all cetacean sightings on the IWDG database. Observations are typically in the summer months between April and September.

The fin whale is the most commonly recorded baleen whale recorded in Irish waters. However, most sightings are Fin whale recorded along the south coast, observed in shallow waters from headlands. Only three records (0.1% of cetacean sightings) were made in the Dublin geographical area. All were in June, but sightings in the Celtic Sea suggest that this species moves to inshore waters in early summer between May and June.

Humpback whale With a similar distribution to that of the fin whale, this deep water species is generally found in the west coast of Irish waters. IWDG database has recorded five sightings of this species (0.4% of all cetacean sightings) Key Absent Present The diet of cetaceans is an important factor in determining their distribution and seasonality at certain locations around Ireland. Whilst larger baleen whales are typically recorded in the deeper waters of the south and west coast, the toothed cetaceans, which primarily feed on fish and squid, are far more common in the shallower inshore waters and are likely to be encountered within the Proposed Project area. The distribution of toothed whales can also vary with water depth, and for some species, there may be some seasonal variation due to foraging habits (Wall et al. 2006). Harbour porpoise (P. phocoena) feed on pelagic fish such as herring, and have been found in areas associated with herring spawning. Many dolphins show seasonal movements into shallow coastal waters, which may coincide with calving or inshore feeding (Boelens et al. 1999). Protection for Cetaceans Ireland is a signatory to conservation-orientated agreements under:

• The Berne Convention on Conservation of European Wildlife and Natural Habitats (1982); • The Bonn Convention on Migratory Species (1983); • The OSPAR Convention for the Protection of the Marine Environment of the north-east Atlantic (1992); and • The Habitats Directive. All cetacean species occurring in European waters are now afforded protection as Annex IV species under the Habitats Directive. Two common species, bottlenose dolphin and harbour porpoise, are Annex II species (i.e. animal species of community interest, whose conservation requires the designation of SACs) (see Section 9.3.1). In 1991, the Irish government declared all Irish waters extending to the outer continental shelf a whale and dolphin sanctuary, claiming that this was a ‘clear indication of Ireland’s commitment to contribute to the

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preservation and protection of these magnificent creatures in their natural environment, and to do everything possible to ensure they should not be put in danger of extinction but should be preserved for future generations’ (Rogan and Berrow 1995). According to the declaration, the sanctuary was empowered under the legal framework already in place, which suggested that the Irish government considered the present legislation to be sufficient to provide full habitat protection to cetaceans within the continental shelf area. The harbour porpoise is a qualifying interest for the conservation objective of the Rockabill to Dalkey Island SAC (Site Code: 003000) within which the proposed outfall pipeline route (marine section) terminates. Toothed Whales and Dolphins The harbour porpoise (Phocoena phocoena) is the smallest cetacean in Irish waters (IWDG 2010) and the most abundant and widespread cetacean species occurring all around the Irish coast. They have a varied diet of herring, mackerel, sprat, pollack, hake, sardine and sandeel; squid and octopus may also be eaten. As they feed predominantly on pelagic fish, they are rarely found over deep water. The population estimate for the Irish Sea is 15,230 (SCANS-II 2008). Sightings are common from June through the autumn/winter, but reduced encounter rates from well-watched sites such as Howth Head, Dublin, suggest they move offshore in spring between March and June (IWDG 2010). Where they go is unknown, but the fact that encounter rates increase in June, when calves are first recorded, suggests they move to offshore calving/breeding grounds. Casual sightings of this species are both numerous and regular and several attempts in estimating the density and local abundance have been carried out by the IWDG. A summary of the survey areas and the locations of casual sightings is shown in Figure 9.4 Casual Sightings and Dedicated Surveys of the Harbour Porpoise. Vessel based transit surveys were carried out in both years in conjunction with some acoustic techniques (T-POD in 2008 and towed hydrophones in 2011) with observations made from the vessel transiting on a set transect (Berrow et al. 2008; 2011). Results from the earlier survey calculated an estimated abundance of just over two individuals per km2 in the northern Dublin area and 1.19 individuals per km2 in a similar area in Dublin Bay. The later study was undertaken in July and covered a much larger area further offshore and to the south of Dublin. This estimated an abundance of 1.58 individuals per km2 for the offshore site, and estimated the total population to be around 1,800 individuals for this area. The Rockabill to Dalkey Island SAC (Site Code: 003000) was established off the Dublin coastline in April 2013 with a key designation for Annex II species harbour porpoise. The occurrence of harbour porpoise within the prescribed marine area was estimated using earlier visual observation and passive acoustic methods to estimate population size, density and distribution. However, the community structure, distribution or habitat use by the harbour porpoise within the SAC is not fully understood. A visual and passive acoustic monitoring survey of harbour porpoise was carried out in the summer of 2013 at the Rockabill to Dalkey Island SAC by Berrow and O’Brien (2013) in order to derive local density and abundance estimates. Operations were based on line-transect surveys over six days between July and October using observers and a towed hydrophone array. A combined total of 640km of track-line effort was carried out within the SAC, which recorded a total of 201 sightings (Figure 9.4 Casual Sightings and Dedicated Surveys of the Harbour Porpoise) comprising at least 292 individual harbour porpoise, a single minke whale (Balaenoptera acutorostrata) and two acoustic detections of dolphins in the absence of corresponding visual sightings. Sightings were made throughout the survey area, although lower numbers were recorded in Dublin bay, possibly due to high vessel activity recorded at the time of the survey. Observations included the sightings of juveniles and calves combined, making up approximately 7% of observations. The study assessed observations at different sea states and concluded that sightings were not statistically affected up to sea states of a Beaufort wind force of 2. The density of the population was estimated to

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be 400 individuals within the SAC, with average density varying from 1.13km2 to 2.61km2 and an overall average density of 1.44±0.09 porpoises per km2. This is similar to that previously recorded in 2008. In 2015, the IWDG and TechWorks Marine Limited were commissioned to carry out a detailed assessment of the nature of marine mammals near the proposed outfall pipeline route (marine section) location as well as monitoring within the SAC. A two-year baseline survey of marine mammals commenced in March 2015 at static acoustic recording sites along the proposed outfall pipeline route (marine section) north of Ireland’s Eye and, additionally, at a single site offshore from Loughshinny for six months starting simultaneously. Three types of surveys were conducted relating to land based observations conducted from vantage points overlooking the study areas, boat based line transect surveys to estimate density and abundances of marine mammals over a larger area, and static acoustic monitoring using C-PODs which are designed to passively detect odontocete echolocation clicks on a continuous basis. The acoustic monitoring provides data when visual surveys are limited due to poor weather conditions or during night-time hours, whilst the boat and land based sightings are used to identify species, group details and behaviour. A summary of the survey effort and sampling locations, along with sighting of marine mammals throughout the survey program, is shown in Figure 9.4 Casual Sightings and Dedicated Surveys of the Harbour Porpoise and Appendix A9.2. Land based monitoring was carried out monthly from 18 March 2015 until 11 March 2017. Just under 144 hours of monitoring was conducted over 23 independent surveys. Marine mammals were sighted on 100% of survey days, with harbour porpoise present on 83% of occasions and 167 sightings recorded made up of 293 animals. Sightings were made up of approximately 80% adults with the remainder juveniles and calves. The calves were only recorded between September 2015 and November 2015, and in August 2016. Sighting rates were calculated based on sightings and number of animals per hour of effort with porpoise sighting rates consistently higher during late summer and autumn (August 2015 - January 2015, and August 2016 - October 2016). Eleven boat based marine mammal surveys were conducted from April 2015 to January 2017. Track-lines were staggered to provide good coverage of the site and to ensure all habitats were surveyed. Harbour porpoise were recorded on 100% of survey days with the greatest number of sightings recorded in November 2015 and August 2016. Group sizes also increased between August 2015 and November in 2015, and in August 2016. The lowest number of sightings were recorded in June 2015, June 2016 and December 2016. However, the sea state was higher during these surveys which would increase the likelihood of missed sightings; therefore, these results must be treated with caution. Calves were only recorded in August 2015, November 2015 and August 2016. Harbour porpoise sightings were regularly distributed across the study area. The average density of animals was greatest in the summer with both August 2015 and August 2016 recording the highest numbers at 1.91ind/km2 and 2.29ind/km2. This fell to between 0.61ind/km2 and 0.89ind/km2 between January and April (2015 to 2017). Static acoustic monitoring was carried out at three sites close to the proposed outfall pipeline route (marine section) using C-PODs for a duration of 750 days (between March 2015 and March 2017). Detections were recorded 96% to 99% of days on average at each site with the daily detection positive minutes (DPM) ranging between 41.3DPM/day to 94.3DPM/day. Detections were categorised into the following categories:

• Season (spring, summer, autumn and winter); • Diel cycle (day and night-time); • Tidal state (ebb, flood, slack high, slack low); and • Tidal phase (spring, neap). The acoustic data demonstrated that all three sites monitored along the proposed outfall pipeline route (marine section) off Portmarnock were used consistently by harbour porpoise on a daily basis. However, presence was

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greater during autumn and winter, during hours of darkness and at slack high tides. When the data from Portmarnock are compared to Loughshinny data collected in 2015 (Meade et al. 2015), results were similar with autumn having the highest detections. However, only six months were monitored. The tidal cycle was not significant at Loughshinny in contrast to Portmarnock, where more detections were recorded during the spring tidal phase. Monitoring index at Loughshinny was high at 9.8%, while at Portmarnock values ranged between 2.8% and 6.6% across sites, suggesting Loughshinny is the most important site for harbour porpoise to be monitored throughout the Construction Phase of the Proposed Project. Trends in the presence of harbour porpoise with diel cycle on the east coast of Ireland have been found to differ geographically, but they are consistently more active at night. The reasons for increased nocturnal activity are uncertain, but could be linked to an increase in prey abundance or activity in the absence of light, as suggested by Todd et al. (2009). Overall, observations through all survey methods showed that harbour porpoise numbers increased in late summer during both 2015 and 2016, which coincided with the presence of calves and may be due to seasonally abundant food sources such as sprat, herring and Trisopterus and gadoid species. Reduced numbers were recorded during late spring/early summer, which may be associated with an offshore movement of this species before calving. The density estimate of harbour porpoise was high and emphasizes the importance of this site for this species, as these are some of the highest densities recorded in Ireland to date (Berrow et al. 2008; 2013; 2015). Of the other species recorded, the common dolphin (Delphinus delphis) is the second most frequently recorded cetacean species in Irish waters (Reid et al. 2003), although it is not the most commonly sighted dolphin off the Fingal coast. Abundance estimates in the Irish Sea from the SCANS-II survey was 366. Between south-eastern Ireland and west Wales, abundance was estimated at 186 in 2004, 1,644 in 2005 and 2,166 in 2006 (Evans et al. 2007). Records from IWDG ferry surveys show a noticeable increase in their numbers in the Irish Sea in the summer and autumn (Berrow et al. 2010). The bottlenose dolphin (T. truncatus) in Irish waters appears to have both a coastal and an offshore distribution (Reid et al. 2003). They are commonly sighted in the Irish Sea and there is a well-studied resident population in Cardigan Bay, Wales. Photo-identification studies suggest that there is a pan-coastal population of bottlenose dolphins which range long distances around all Irish coasts and to the UK (O’Brien et al. 2009). The SCANS-II surveys estimated abundances of 235 in the Irish Sea (SCANS-II 2008). This is the third most frequently recorded species in Irish waters (Berrow et al. 2010), and they have a year-round distribution with a peak between May and September (although this may be due to an increase in observers during these months). Risso’s dolphin (Grampus griseus) occur predominantly in shelf and coastal waters in Ireland. The south-east coast is one of the areas of highest abundance for this species. A breeding population appears to be present in the southern Irish Sea and the species is also regularly recorded around the Isle of Man (Berrow et al. 2010; Baines and Evans 2009). They have been recorded throughout the year in Irish waters with a wide distribution (Aecom and Metoc 2010) and there is some evidence of seasonal movements in the Irish Sea (Baines and Evans 2009). Risso’s dolphin feed mainly on squid, cuttlefish and octopus, and small quantities of fish and co-operative foraging has often been observed. The Orca whale (O. orcinus) has been observed off all Irish coasts and in the Irish Sea. Sightings occur predominantly in inshore coastal waters (Berrow et al. 2010). There is some evidence of increased sightings during late summer and autumn, with occasional incidences of killer whales entering harbours and estuaries.

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The long-finned pilot whale (Globicephala melas) occurs predominantly in the deeper waters of the continental slopes and waters to the west of Ireland. The species breeds in Irish waters and groups have been infrequently recorded in shallower waters off the southern and south-western coasts of Ireland, and as far east as the English Channel (southern Irish Sea) (Berrow et al. 2010). This is not a species that is likely to occur within the proposed study area. Baleen Whales As noted above, the distribution of large baleen cetacean species in the Dublin inshore geographical area, such as the humpback (Megaptera novaeangliae) and fin whales (Balaenoptera physalus), is very rare and unlikely. The smaller rare but regular baleen species recorded in the area are the minke whales (Balaenoptera acutorostrata), equivalent to around five observations per year (IWDG database). The distribution of prey is an important factor in the distribution of baleen whales. They typically feed on krill and pelagic schooling fish species, and their distribution is often related to oceanographic features such as fronts, upwellings and associated areas in which prey availability is high. Some species also eat squid depending on the season. In the summer months, minke whales (B. acutorostrata), for example, feed mainly on fish in the inshore waters around the UK and Ireland (Pollock et al. 1997). The minke whale is the most widespread and frequently recorded baleen whale in Irish waters. They are present along all Irish coasts (Reid et al. 2003; Berrow et al. 2010) and sightings occur in the Irish Sea from May to July (IWDG 2011a). Minke whales have the most varied diet of all baleen whales, feeding on various small fish, including capelin, sandeel, herring and cod; they may also feed on small squid (IWDG 2011b). Minke whales have been stranded on every coastline in Ireland with the stranding incidence reflecting their distribution and temporal occurrence (IWDG 2011c). Fin whales (B. physalus) are seasonally abundant in shelf edge waters to the west of Ireland and in shelf waters off the southern coast of Ireland. However, there have been rare sightings in the St. George’s Channel (southern Irish Sea) and off Dublin (IWDG 2011a) between June and September. Fin whales have a varied diet, comprising fish species such as herring, mackerel, cod, sand lance, squid and capelin, but young whales may take small invertebrates like krill and copepods. Humpback whales (M. novaeangliae) have been recorded in small numbers inshore off all coasts including the Irish Sea (Berrow et al. 2002). This species has been recorded in all months of the year and was sighted off the south-east coast in late 2010 and early 2011. It has also been recorded in St. George’s Channel and the Irish Sea (IWDG 2011d). Pinnipeds There are two species of seal native to Irish waters, both of which are found within the proposed outfall pipeline route (marine section). These are the grey seal (Halichoerus grypus) and the smaller and slightly rarer harbour seal (also known as the common seal (Phoca vitulina)). Both species are listed as qualifying interests for the Lambay Island SAC (Site Code: 00204) located 9.3km north-east of the proposed outfall pipeline route (marine section) (including the proposed marine diffuser). Breeding sites exist for both species here, although the grey seal also has breeding sites on Ireland’s Eye (approximately 1km south) and on Dalkey Island (approximately 14.9km south). Given the proximity and size of these populations, it is extremely likely that seals currently forage within and around the proposed discharge site. The grey seal is present at the site throughout the year, including during its breeding (around August to December) and moulting seasons (around December to April). During the breeding season, the relationship between pup production and total population size is not well known. An estimated 56 pups were born in the Lambay Island SAC in 2005. The corresponding minimum population estimate for the site numbered between 196

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and 252 grey seals of all ages. Harbour seal are also present on Lambay Island throughout the year, including during its breeding (around May to July) and moulting seasons (around August to September). A total of 31 harbour seal were recorded ashore within Lambay Island SAC in August 2003 during a national aerial survey for the species, while maximum counts of 38 to 47 harbour seal were recorded more recently during the moult season. The haul-out groups of harbour seals have tended historically to be found among inshore bays and islands, coves and estuaries (Lockley 1966; Summers 1980), particularly around the hours of lowest tide. The grey seal breeds on exposed rocky shores, on sand bars or in sea caves with ready access to deep water. Other haul-out areas for the grey seal are located on exposed rocky areas or steeply shelving sandbanks. Results from the recent IWDG study revealed the presence of seal within the survey area. This survey clearly demonstrated that the area off Portmarnock is important for grey seals, which were recorded throughout the year in small numbers and distributed throughout the survey area. Peaks in sightings from Howth Head occurred during spring and autumn, coinciding with pupping and post-moult periods at the local well-known breeding and haul out sites at Lambay Island, Skerries and Ireland’s Eye. In all, 260 sightings of grey seal were recorded during the survey totalling 325 animals. Sighting rates were more consistent over the survey period with the highest sightings in April 2015, although high numbers were also recorded in September 2015, January 2016 and October 2016. Group size also increased during this time. Grey seal was often recorded feeding within close proximity to the northern cliffs of Howth Head. Otters In addition to cetaceans and pinnipeds, the otter Lutra lutra may be found in shallow intertidal areas of the marine environment (such as estuaries), particularly during winter (Bailey and Rochford 2006). To the north of the proposed outfall pipeline route (marine section) area, the Boyne River (approximately 35km north of the proposed outfall pipeline route (marine section)) is designated as an SAC partly on the basis of the presence of otters. As such, otters may reasonably be expected to occur occasionally in the area. However, whilst this cannot be ruled out for the Baldoyle Estuary, they are unlikely to be found on the exposed sandy beaches of the Velvet Strand.

9.3.8 Fish and Shellfish Regional Context Inshore areas of the Irish Sea are generally characterised by sandy substrates where flatfish such as plaice (Pleuronectes platessa), dab (Limanda limanda) and sole (Solea solea) tend to predominate (Cefas 2007). Other common species are thought to include lesser weever (Echiichthys vipera), common dragonet (Callionymus lyra), tub gurnard (Chelidonichthys lucerna) and gobies (Pomatoschistus spp.) (Fishery Agencies 2005). Otter trawl survey data also indicate that higher abundances of species such as clupeids, haddock (Melanogrammus aeglefinus) and Norway pout (Trisopterus esmarkii) are found in the western Irish Sea than in the east (Ellis et al. 2002). Sampling within Dublin Bay revealed a generally sandy seabed, becoming coarser approximately 3km from the beach. This shallow environment will commonly support an array of demersal fish species (in particular flat fish) as well as ecologically and commercially important species such as sandeels and juvenile fish species avoiding deeper waters. Baseline information regarding the fish and shellfish assemblage in the vicinity was collected through a scientific 2m beam trawl survey, a beach seine net survey and a common whelk survey in September 2015 and September 2017. Sampling was conducted at stations along and adjacent to the proposed outfall pipeline route (marine section), with single reference stations positioned 1km to the north of the proposed outfall pipeline route (marine section) in both the beam trawl and seine net surveys.

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Finfish The site-specific survey findings showed a total of 18 species recorded in the beam trawl survey, and nine species in the beach seine net survey. In both surveys, plaice represented the most abundant species, followed by sand goby (Pomatoschistus minutus). Greater abundances for both species were recorded in the seine nets than the trawls. Dab were found to be almost equally abundant in the trawl samples to sand goby, but were almost entirely absent from the seine net catches. Using a combination of these methods, clupeids, specifically herring (Clupea harengus) and sprat (Sprattus sprattus), were abundant in the water column but are known to form dense spawning aggregations at the seabed. The presence of many small herring (5cm to 9cm) indicates a potential nursery area; juvenile herring are known to occupy shallow waters separate to the adults before moving into deeper waters after approximately two years (ICES 2006). This is supported by Ellis et al. (2012), who identified a high intensity herring nursery ground within approximately 8km of the proposed outfall pipeline route (marine section). Landings Data Beam trawl surveys conducted throughout the Irish Sea from 1993 to 2001 (Parker-Humphreys 2004) provide valuable information on the diversity and relative abundance of demersal fish species in the Malahide Bay area. The most common species include:

• Commercial flatfish: plaice (Pleuronectes platessa), sole (Solea solea), dab (Limanda limanda) and lemon sole (Microstomus kitt); • Commercial roundfish: cod (Gadus morhua) and whiting (Merlangius merlangus); • Monkfish (Lophius piscatorius); • Elasmobranchs (sharks and rays): lesser-spotted dogfish (Scyliorhinus canicula), thornback ray (Raja clavata) and spotted ray (Raja montagui); and • Non-commercial fish: poor cod (Trisopterus minutus), bib (T. luscus), scaldfish (Arnoglossus laterna), common dragonet (Callionymus lyra), gurnards (Triglidae sp.), pogge (Agonus cataphractus) and lesser weever (Echiichthys vipera). Landings registered with the ICES in the Dublin Bay area recorded an average of 3.79 tonnes of demersal fish, 0.12 tonnes of pelagic fish and 9 tonnes of shellfish for this stretch of coastline between Wicklow and Lambay Island between 2006 and 2008 (Marine Institute 2010). Overall, the demersal fishery is dominated by shellfish. This is partially due to the extended areas of hard ground recorded within the survey area. Species with Defined Spawning and Nursery Grounds A number of fish species have defined spawning and nursery grounds within the area of the proposed outfall pipeline route (marine section). These species are detailed in Table 9.15 based on the data provided by Ellis et al. (2010; 2012) and Coull et al. (1998). It should be noted that additional species may utilise the proposed outfall pipeline route (marine section) area as spawning and/or nursery grounds, although these are not expected to be significant enough to be affected by the Proposed Project. The ecology of the principal fish species identified during sampling operations in 2015 and 2017 is described later in this Section.

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Table 9.15: Spawning Periods of Key Species

Spawning Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Nursery Anglerfish Cod * * Haddock Herring Horse mackerel * * Lemon sole Ling Mackerel * * Plaice * * Sandeel Sole * Sprat * * Whiting

Spotted ray ? * * * ?

Thornback ray * * * * *

Spurdog Viviparous species – gravid females can be present year-round

Tope Viviparous species – gravid females can be present year-round

? possible High Intensity Low Intensity Intensity Unknown * Peak Spawning spawning

Species of Conservation Interest The three species of lampreys (Petromyzontidae) that occur in Ireland are listed under Annex II of the Habitats Directive. Kelly and King (2001) summarised their distribution in Irish waters. While the brook lamprey (Lampetra planeri) is recorded from the Boyne and Liffey catchments (to the north and south of the proposed outfall pipeline location (land section), respectively), this species is exclusively found in freshwater. The river lamprey (L. fluviatilis), which is anadromous (i.e. uses coastal/marine habitat and then ascends rivers to spawn), is the least widely reported of the three species in Ireland, although it is recorded from the lower Boyne River to the north, contributing to its SAC status. The sea lamprey (Petromyzon marinus) is also anadromous and this species is more widely distributed in Ireland, although it is not recorded in the Boyne or the Liffey catchments (Kelly and King 2001). Shad are related to herring, and are also anadromous. Both the allis (Alosa alosa) and twaite shad (A. fallax), occur in Ireland and are designated as Annex II species. Four SACs in Ireland have been designated based on their importance to shad, although these are all in the south of the country (King and Roche 2008). Shad are not regularly recorded in the area of the proposed outfall pipeline route (marine section) location. The smelt (Osmerus eperlanus), an anadromous Irish Red Data book species, has not been recorded from the east coast of the Republic of Ireland (Quigley et al. 2004). Both salmon (Salmo salar, a Habitats Directive Annex II species) and sea trout (S. trutta morpha trutta) are anadromous and occur in rivers and coastal waters throughout Ireland. Both species are of great importance to recreational and commercial fisheries. The inshore areas of the proposed outfall pipeline route (marine section) are likely to be used by both species, given that important rivers exist relatively nearby. For example, the Boyne River, 35km to the north of the proposed outfall pipeline route (marine section), is designated as an SAC partly

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based on the presence of salmon and is renowned as a salmon and sea trout fishing river. Adjacent rivers to the site have the following salmonid status (see Chapter 11 Biodiversity (Terrestrial and Freshwater Aquatic) in Volume 3 Part A of this EIAR):

• The Sluice River (IE_EA_09_1532) and its tributaries constitute a salmonid system. The system (main channel and tributaries) supports brown trout (S. trutta) throughout and eels (Anguilla anguilla) in its lower reaches (in addition to other fish species). It should be highlighted that recent surveys of the Sluice have recorded the presence of brown trout at least as far upstream as the Abbeyville Estate; • The Mayne River (IE_EA_09_1428) constitutes a non-salmonid system because of the presence of an impassable barrier to fish movement at the lower end of the system. However, water quality has been noted as improving and IFI is currently assessing the viability of a salmonid reintroduction programme. Local developers have installed and configured instream features in compliance with salmonid waters requirements as per ‘best practice’ for this river; • The Santry River (IE_EA_09_1507) is non-salmonid because of the presence of a number of impassable features to fish located toward the lower end of the system. IFI’s policy is to maintain watercourses in their open natural state in order to prevent habitat loss, preserve biological diversity and aid in pollution detection; and • The Tolka River and its tributaries constitute a salmonid system. The system (main channel and tributaries) supports brown trout (S. trutta) throughout, sea trout (S. trutta morpha trutta) and eels (A. anguilla) in its lower reaches (in addition to other fish species). Salmon have recently been recorded from the lower reaches of this river system. In addition to these inshore species, a number of offshore species of conservation interest have been recorded from the area, including the basking shark (Cetorhinus maximus) (Berrow 2008), which is more common in the western Irish Sea, and the sunfish (Mola mola). A number of diadromous species of conservation importance may utilise the area of the proposed outfall pipeline route (marine section) during migration or when foraging. These species are listed in Appendix A9.1. Most elasmobranchs (sharks, skates and rays) are considered slow growing and late maturing with a low rate of reproduction (fecundity) when compared with other bony fishes (Camhi et al. 1998; Musick and Bonfil 2005). They are therefore sensitive to commercial exploitation through their resultant slow rate of stock increase (Musick and Musick 2011). Several common species with conservation designations and/or declining stocks potentially occur near the proposed outfall pipeline route (marine section) and are listed in Appendix A9.1. A number of commercially exploited species which are expected to be present within the proposed outfall pipeline route (marine section) area are listed under UK Biodiversity Action Plan, OSPAR, IUCN Red List and the Bern Convention and are therefore of conservation interest. A list of relevant species and their designations is given below in Appendix A9.1 or Table 9.16. These include sandeels (Ammodytes marinus and A. tobianus), cod (Gadus morhua), turbot (Scophthalmus maximus) and haddock (Melanogrammus aeglefinus). Sand goby (P. minutus) and common goby (P. microps) are not commercially exploited, and are also of conservation interest. Both species are listed under the Bern Convention (Appendix III), and relatively high numbers of what was assumed to be sand goby in the field (may possibly be common goby) were found in both the scientific 2m beam trawl survey and the beach seine survey. Species such as herring, sprat and sandeel are considered key prey species for many predators such as marine mammals, piscivorous fish and birds (Furness 2002; Pitcher and Wyche 1982; ICES 2006; 2006b). Cod are known to prey upon small members of the Gadidae family (Trisopterus spp. and whiting), various flatfish, herring and sandeel (Arnett and Whelan 2001). There are also records of juvenile plaice in the stomachs of cod, whiting,

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saithe (Pollachius virens), pollack (P. pollachius) and older plaice (Nash and Geffen 2000). This suggests that the high intensity plaice nursery ground in the area of the proposed outfall pipeline route (marine section) may be of some importance as a feeding area for other commercial fish species. Shellfish The site-specific survey data indicated that a total of 18 species of shellfish were recorded in surveys surrounding the survey area. Six of these were recorded in the targeted whelk survey (RPS 2015) and 10 were recorded as bycatch from the beach seine net survey, three of which were also recorded in the aforementioned survey (Table 9.16). An additional five shellfish species were also noted as commercially targeted by fishermen in the area (Marine Institute 2013). Shellfish species that are commercially targeted in the area are European lobster (Homarus gammarus), brown crab (Cancer pagurus), velvet crab (Necora puber), common shrimp (Palaemon serratus), common whelk (Buccinum undatum), great scallop (Pecten maximus), razor clam (Ensis siliqua) and the blue mussel (Mytilus edulis). All species are targeted with static fishing gear, with the exception of scallops, mussels and razor clams, which are fished with mobile gear.

Table 9.16: Principal Species of Shellfish Recorded

Conservation Status

Common Name Scientific Name Bern UK Biodiversity Survey* OSPAR IUCN Red List Convention Action Plan European lobster Homarus gammarus - Least concern - MI Brown crab Cancer pagurus - - na - RPS & ASU Green crab ** Carcinus maenas - - na - RPS & ASU Harbour crab** Liocarcinus depurator - - na - RPS & ASU Scorpion spider crab** Inachus dorsettensis - - na - RPS Velvet swimming crab Necora puber - - na - ASU Risso's crab** Xantho pilipes - - na - ASU Small spider crab** Majoidea - - na - ASU Hermit crab** Pagurus bernhardus - - na - ASU Rock shrimp** Palaemon elegans - - na - RPS Brown shrimp** Crangon crangon - - na - ASU Aesop shrimp** Pandalus montagui - - na - ASU Common shrimp Palaemon serratus - - na - MI Common whelk Buccinum undatum - - na - MI & RPS Queen scallop** Aequipecten opercularis - - na - ASU Great scallop Pecten maximus - - na - MI Razor clam Ensis siliqua - - na - MI Blue mussel Mytilus edulis (in beds)   na  MI * Survey references: MI = Marine Institute (2013); RPS = RPS (2015); ASU = Aquatic Services Unit (2015). ** Present as bycatch and not commercially fished na = not assessed by the IUCN The common whelk fishery off the east coast of Ireland is composed of four sectors (Dublin, Arklow, Courtown and Wexford) and occupies approximately 2,000km2, of which the Dublin sector (vessels from Dun Laoghaire and Howth) records the lowest landing densities. The main Dublin Whelk fishing grounds are the sandbank areas near the Kish Bank. Additionally, results for the 2013 survey conducted around the proposed outfall pipeline route (marine section) show the whelk abundance to be positively correlated with water depth, with 45% to 56% of whelks sampled considered mature adults (RPS 2013).

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The mussel seed fishery is restricted to 70 days per year and occurs in very limited areas. No mussel bycatch was recorded in fishery surveys performed or were conspicuous in sidescan sonar data acquired over the proposed outfall pipeline route (marine section). However, beds have been recorded on ‘sand banks and on coarse current swept sediments and rocky habitat’ (Marine Institute 2013), at the base of the north-west sublittoral reef on Ireland’s Eye (BSL 2015a) or as a seedbed of the horse mussel (Modiolus modiolus) on the maerl sands immediately outside Howth harbour (BSL 2012). There is only a small scale coastal scallop fishery in this region with vessels operating from Kilkeel, Dundalk and Howth/Dun Laoghaire: each is under 15m beam length and can carry up to 12 dredges (Marine Institute 2013). Species of Conservation Interest Of the shellfish species recorded, it is only the European lobster (H. gammarus) that, as a species, is of conservation interest. However, where found in high densities, the blue mussel (M. edulis) can form beds that are a designated habitat and biotope, ‘Intertidal M.edulis Beds on Mixed & Sandy Sediments’, listed by the OSPAR commission as threatened or in decline where they occur in the Celtic Seas. Smothering through siltation and physical damage are ranked as medium and high threats to this habitat, as were heavy metal pollution and introduction of microbial pathogens, respectively. The blue mussel, along with the larger horse mussel (M. modiolus), can also be found in large aggregations to form biogenic reefs which are designated as an Annex I habitat under the Habitats Directive, although these have not been recorded within close proximity of the proposed outfall pipeline route (marine section). The European lobster is listed in Appendix III of the Bern Convention as a protected fauna species. This species is listed as least concern on the IUCN Red List with a stable population and is not listed as a Habitats Directive Annex II species. The fishery is currently managed in the UK with a minimum landing size of 87mm carapace length, and it is strictly forbidden to land buried females. Numerous regions successfully manage the stocks with schemes such as V-notching and introduction of maximum landing sizes; however, no such schemes are currently in place along the Fingal coastline. Commercial Shellfish Landings registered with the International Commission for the Exploration of the Sea (ICESin the Dublin Bay area recorded an average of nine tonnes of shellfish for this stretch of coastline between Wicklow and Lambay Island between 2006 and 2008 (Marine Institute 2010). Overall, the demersal fishery is dominated by shellfish as bottom trawling is generally poor. This is partially due to the extended areas of hard ground recorded within the survey area. Fishing activity in the Irish inshore section is from vessels targeting razor clams (with the majority also able to target cockles) and those operating static gear, specifically potting for crab and lobster. Razor clam vessels active in the area are from home ports between Dundalk in the north down to Howth in the south, and number more than 30. In addition to the razor clam fishery, there are a small number of local boats who target shellfish on ground north of Lambay Island throughout the year for different gears. The whelk fishery is a small fishery but has been growing in recent years with the interest from overseas markets (Korea). Some boats are known to land in Howth and Dublin, but the majority of the fishery is south of Dalkey Island (Fahy et al. 2005). It should be noted that the proposed outfall pipeline route (marine section) lies outside designated shellfish waters under the Quality of Shellfish Waters Regulations 1994 (S.I. No. 200 of 1994). All of these inshore fisheries are summarised in Table 9.17 and in Figure 9.5 Inshore Shellfish Grounds Along the Fingal Coast. A detailed biology of these commercial fish species is included in Appendix A9.1.

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Table 9.17: Summary of Local Shellfish Fisheries in Northern Fingal

Species No. of Boats Season Brown (edible) crab (Cancer pagurus) 4 June to December Velvet swimming crab (Necora puber) 11* All year: These boats fish brown crab later in the summer and 4 velvet crab for only part of the season European lobster (Homarus gammarus) 4-5 All year round Whelk (Buccinum undatum) unknown Summer through to later autumn Razor clam (Ensis sp.) Unknown October to April Shrimp (Palaemon serratus) 4 September to February * All of the boats that target velvet crab would also have a bi-catch of lobster and brown crab. Dredging is restricted inshore (as defined by the Sea Fisheries Protection Authority). However, fishermen have previously stated that activity often occurs in grounds in between designated dredging sites. As the activity is mostly concentrated in small areas, the result is that the seabed can be excavated to depths of 30cm. Recreational Fisheries Recreational fishing is also important in the region of. Angling is very active along the Fingal coastline with fishing from beaches, harbours, piers and from boats both close to shore and offshore over wrecks and reefs (Ecoserve 2006). Near the proposed outfall pipeline route (marine section), there is notable Angling activity at Howth Harbour at the East and West Pier where whiting, pollack, coalfish and codling can be caught during summer and autumn. Small boats can be launched for general ground fishing around Ireland's Eye and on the Kish Bank. Species to be expected are coalfish, pollack, whiting, dogfish, mackerel and flatfish. To the east of the harbour is Balscadden Rocks where rock fishing takes place for mackerel (in season), plaice, dabs, dogfish, pouting, whiting and codling. At the Baily, mackerel (in season), coalfish, plaice, dab, dogfish, wrasse and whiting have been recorded. At Red Rock in Sutton, bass and flatfish have been recorded. Velvet Strand in Portmarnock is an important shore angling venue. Around the Martello Tower, occasional bass and flounder can be fished for from the rocks, whilst the beach at the strand is used for distance casting and will produce dogfish and occasional codling and whiting in the Autumn. Estuarine Fisheries Many species avail of the highly productive nature of many estuaries and their use will vary with the seasons. Some fish species can be found in the estuaries the whole year round. Other fish are migratory, travelling through estuaries from the sea to reach spawning grounds in freshwater, such as salmon and lamprey, while others, such as eel, migrate down estuaries to the sea. The proposed outfall pipeline route (marine section) is close to Baldoyle Estuary. Rogerstown Estuary lies to the north. Between the two is the Malahide - Broadmeadow Estuary. A total of 24 species or taxa were recorded, from this and the Rogerstown Estuary by King and Green in 2003. A summary of these is listed in Appendix A9.1.

9.3.9 Summary Evaluation (Importance) of Key Marine Ecological Receptors and Habitats A summary of the key sites, habitats and sensitive receptor species are listed in Table 9.18. The Proposed Project area overlaps directly with two marine related SACs, although additional habitats and species of conservation importance are recorded within the general vicinity. Some sensitive receptors represent qualifying species at neighbouring SACs or are known to exist in the region of the Proposed Project.

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Table 9.18: A Summary of the Key Sites, Habitats and Sensitive Receptor Species

Receptor Importance Justification

Designated sites

Baldoyle Bay SAC Very high Designated as an SAC for salt meadows and mudflats (see Table 9.7). (Also qualifies for designation as an SPA by regularly supporting internationally important populations of wintering and nationally important populations of birds. Baldoyle Bay also qualifies for a Ramsar Site). The Proposed Project passes through the site.

Rockabill to Dalkey Island SAC Very high Designated SAC for qualifying marine habitat and Annex II species. The Proposed Project (proposed marine diffuser and part of the proposed outfall pipeline route (marine section)) is located within the SAC.

Ireland’s Eye SAC Very high Designated SAC for terrestrial habitats. The proposed outfall pipeline route (marine section) is 0.8km north of the island.

Marine habitats

Mudflats and sandflats not Medium Several muddy biotopes are present. Important habitat for the wintering birds (see covered by seawater at low tide Chapter 10 Marine Ornithology).

Salicornia and other annuals Very high Qualifying saltmarsh interest for the Baldoyle SAC in close association with the colonising mud and sand other saltmarsh habitats.

Atlantic salt meadows (Glauco- Very high Qualifying saltmarsh interest for the Baldoyle SAC in close association with the Puccinellietalia maritimae) other saltmarsh habitats.

Mediterranean salt meadows Very high Qualifying saltmarsh interest for the Baldoyle SAC in close association with the (Juncetalia maritimi) other saltmarsh habitats.

Rocky Reefs Very high Rock coastline with steep-sided, wave-swept, littoral and sublittoral rocky reef complexes. This is a qualifying interest for the SAC, although acknowledged as poor quality due to high siltation. Conservation objective is to maintain favourable conservation status and to prevent the permanent removal of habitat area.

Species of conservation/commercial value

Atlantic salmon Medium Not listed as a qualifying species in the Rockabill to Dalkey Island or Baldoyle Estuary SACs. It is expected to be present within the project area. Listed in Annex II (Habitats Directive). It is also OSPAR listed as a threatened species. Migratory species.

Sea and river lamprey Medium Listed in Annex II (Habitats Directive), also recorded in river systems north and south of the Proposed Project area. Migratory species.

Harbour porpoise Very high Annex II designated species and qualifying interest for the Rockabill to Dalkey Island SAC. This is a species of international importance resident in Irish waters and occurring regularly in the Celtic sea. A European Protected Species.

Bottlenose dolphin Medium Annex II species of international importance and occurs in the region. A European Protected Species.

Grey seal Medium Annex II species and a qualifying species in neighbouring SAC, with an important breeding population on Lambay Island but may also breed in Ireland’s Eye. Regularly sighted within the region.

Common seal Medium This species is of national importance and is sighted in the region, although not in high numbers. Annex II species and a qualifying species in neighbouring SAC, with

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Receptor Importance Justification an important breeding population on Lambay Island. Occasionally sighted within the region.

Otters Low Boyne River is designated as an SAC partly on the basis of the presence of otters, so they could possibly occur occasionally in the area, particularly in the Baldoyle Estuary area. Otters are a European Protected Species (see Chapter 11 Biodiversity (Terrestrial and Freshwater Aquatic) in Volume 3 Part A of this EIAR.

Shellfish Low Mussel reefs (M. edulis) can be found in dense reefs to the west of Ireland’s Eye and form an Annex I biogenic reefs habitat listed by OSPAR as threatened or in decline where they occur in the Celtic Sea. Not found along the proposed outfall pipeline route (marine section).

Marine fish Low Several fish species use the Proposed Project area for spawning and/or nursery. Key species include cod and spurdog, both listed as threatened under OSPAR and vulnerable under the IUCN Red List. Sandeels, herring, sprat and plaice are important to avian and mammal predators. Whiting are also found to spawn in the Proposed Project area or use the shallow embayment as a nursery area.

Benthos Negligible The benthos over the Proposed Project area is diverse but typical for this area of the Irish coastline. There are no key species of conservational importance, although the benthos is a resource that is important to other ecological groups (e.g. birds and fish species), as well as some shellfish fisheries.

9.4 Impact of the Proposed Project – Construction Phase The construction and operational methodology is described in Chapter 4 Description of the Proposed Project in Volume 2 Part A of this EIAR. The proposed outfall pipeline route (marine section) is broken down into different geographical sections which each relate to different construction methodologies and consequently have varying potential for impacts to the marine ecology. These can be summarised as follows:

• Two proposed temporary construction compounds for microtunnelling will be built adjacent to the Baldoyle Estuary SAC and SPA; • A tunnel will be constructed beneath Baldoyle Bay SAC and SPA and will run for approximately 2km below Velvet Strand out to 600m from the coast. It is estimated that microtunnelling would progress at a rate of approximately 60m per week and that the tunnelling would take in the region of 12 months including site mobilisation; • The remaining section of the proposed outfall pipeline route (marine section) runs a further 4km out to north of Ireland’s Eye and terminates with the proposed marine diffuser. This section of the proposed outfall pipeline route (marine section) will be constructed using surface dredging using a combination of backhoe dredger and/or TSHD in the deeper section (water >15m deep): o Where the backhoe dredger is used, the dredged material will be disposed to a hopper barge, which will then deposit the dredged material through its bottom doors in a linear stockpile parallel to the pipeline trench within the 250m proposed construction corridor for subsequent reuse; o Where the TSHD is used, one or two suction tubes, equipped with a drag head, will be lowered on the seabed and the drag head trailed over the trench. A pump system will suck up a mixture of sand or soil and water, and discharge it in the ‘hopper’ or hold of the vessel. Once fully loaded, the vessel will move off the trench alignment and deposit the material through its bottom doors in a linear stockpile parallel to the pipeline trench within the 250m proposed construction corridor for subsequent reuse;

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o The trench is envisaged to be 2.5m deep and 5.0m wide at base but between 20 and 40m wide at the surface, subject to seabed sediment type; and o The construction period is estimated to take six months; • The proposed outfall pipeline route (marine section) will be installed using a float and lower method using a long length large diameter polyethylene pipe and lowering this into the dredged sections. These pipes will be delivered to Dublin Port or to sheltered waters along the proposed outfall pipeline (marine section) prior to ballasting and final pipe assembly operation. In sheltered waters, a floating jack up platform supported by tugs and multicat vessels would be used to assemble the pipe strings and place the concrete collars. Collars would be delivered on a daily basis by ship to platform. Pipe assembly along a quay wall requires mobile cranes to lift the concrete collars into place. Collars would be delivered by road to the port; • At the tunnel/subsea pipeline interface, approximately 600m offshore, a temporary structure will be required consisting either of a cofferdam or a pre-excavated section of trench (filled with loose sand/granular material sourced from elsewhere along the trench alignment) to retrieve the TBM from the microtunnelled section; • As the proposed outfall pipeline route (marine section) will cross the Hibernia Atlantic fibre optic cable, a temporary construction supporting the cable during pipeline excavation will be required. This will require additional sheet piling operations at this location; and • The diffuser section consists of one or more vertical riser pipes which are attached to the main pipeline after it is lowered into the trench. The actual diffuser valves are then attached to the riser pipes. The main pipeline will be supplied with pre-installed flanged openings (capped) for the diffusers. Once the pipe is lowered into the trench, divers will remove the flanged caps and attach the riser pipes via bolted connections. The trench is then backfilled. Divers will then attach the diffuser valves, again using bolted connections, to the end of the riser pipes which are protruding above the reinstated seabed. Protective covers in the form of precast concrete or steel are then placed over the diffuser valves.

9.4.1 Construction of the Microtunnelling Compounds Adjacent to the Baldoyle Estuary and Construction Works Upstream of Marine Environment with Potential for Contaminated Runoff The driveshaft for the proposed microtunnel will be located outside the Baldoyle Bay SPA/SAC. Consequently, the potential impact to the marine ecology from this part of the operation would be limited to an indirect impact where disturbance occurs through visual and airborne noise impacts, or by the escape of waste products into the estuary. The most sensitive receptor within the estuary from the compound construction is over-wintering birds (see Chapter 10 Marine Ornithology). Migratory and juvenile fish may also use the estuary during higher states of the tide and benthos are an important food source for the over-wintering bird population. However, the use of bunded protection within the compound would negate the impact from these terrestrial operations to the marine system, and the Baldoyle Estuary is not a known migration route for any sensitive marine species. The three saltmarsh related qualifying species within the estuary (i.e. Salicornia and other annuals colonizing mud and sand, and Atlantic and Mediterranean salt meadows) are all located on the upper parts of the estuary and are surrounded by existing erosion channels below the level of the habitat. The main channel, fed by the Sluice River in the north and met by the Mayne River along the western shoreline, meanders along the central part of the estuary below the main vegetation zone. The tidal range within the estuary is 4.1m during spring high waters, with the saltmarsh only surrounded by water during the upper third of the tidal cycle, and only covered by estuarine waters during high water spring events. Consequently, the main saltmarsh is largely unaffected by the water quality during the majority of the tidal cycle and from riverine inputs for a significant period of time. When a spring high water event occurs, the overall volume of Baldoyle Bay increases by approximately 1.5 million cubic meters due to the additional 80cm rise in tidal height, increasing the dilution effect of any pollutant within the estuary during this period.

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Pollution events that may occur upstream during construction or from the adjacent compounds are deemed to be of low risk, with mitigation applied within the Construction Environmental Management Plan (CEMP) to trap or isolate discharges where they are likely to occur. However, in the event that a small pollution event does occur, the likely route for this material into the estuary would be the existing eroded riverine flow channels within the estuary which remain away from the main saltmarsh areas. In the event that the estuary is at high water during a spring event where this material may be dispersed onto qualifying saltmarsh habitats, the higher level of seawater exchange within the estuary is expected to dilute this material to a negligible level of impact. In addition to the saltmarsh habitats, Baldoyle Bay SAC is also designated for mudflats and sandflats not covered by seawater at low tide (1140), located throughout the whole of the Bay and a section of coastline named the Velvet Strand along the Portmarnock coastline. The properties of supporting sediments within this habitat varies from fine sand dominated by Angulus tenuis and Tubificoides benedii in the mouth and along the eastern shoreline and Estuarine sandy mud with Pygospio elegans within the bay, based on changes in the hydrodynamic regime within the SAC. The pathway of possible discharges described above would be directly over this habitat, but the permanent habitat area is stable or increasing, subject to natural processes. As the nature and scale of possible contamination to the site from upstream activities is deemed to be rare, minor and very short lived, it is concluded that the resilience of the receiving habitat is such that this potential would have a negligible impact within the designated site. Impact The magnitude of any noise/vibration impact or pollution impact will be negligible based on the limiting factors as described above and the protocols outlined in the CEMP, suggesting a Negligible impact significance to sensitive saltmarsh, benthos and juvenile fish species (including migratory fish species). Otters may occasionally use the estuary whilst other marine mammals are not expected to populate the estuary due to its very shallow nature and limited coverage by the tide. Whilst their ecological value varies from low (otters) through to high (harbour porpoises outside of the SAC), the negligible impact magnitude would produce a likely Negligible impact significance.

9.4.2 Tunnelling Underneath Baldoyle Bay and Tunnelling Compounds Habitat Loss/Disturbance No wetland habitat loss or disturbance is predicted within Baldoyle Bay SAC, as a trenchless construction method is to be adopted from west of Baldoyle Bay to approximately 600m east of the Velvet Strand shoreline. Whilst the use of this tunnelling technique will reduce the possibility of surface impacts to a very low level, the risk of low level noise/vibration, a surface breakout or the requirements for a surface intervention cannot be negated completely as will be discussed below.

Surface Venting (Air Breakout) The risk and magnitude of air breakout may vary significantly when comparing different microtunnelling techniques, due to the requirement for compressed air within varying technical solutions. It is therefore possible that this risk can be removed completely for some microtunnelling techniques. Compressed air is used within the TBM to maintain a slight positive pressure. This can occasionally escape to the surface through a trickle of air bubbles and create small areas of surface sediment loss through liquefaction and winnowing of fines in prevailing marine currents. Whilst this does not have a chemical impact on the surrounding sediments, this can create a small area of physical impact to the SAC wetland habitat in the form of a small pock mark or shallow crater. This may have a very localised impact on the Wetlands. Wetland habitats typically would

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reinstate themselves naturally over an extended period of tidal activity, although occasionally, some surface intervention may be required to assist in reinstatement for larger features in cohesive sediments, if encountered. Impact Overall, the potential for this impact would be highly unlikely. However, as this may create some minor physical damage, this could have an adverse effect on the saltmarsh habitat, which is of very high ecological value but of negligible magnitude, resulting in a likely Minor significant impact. Should this occur, this would be a very small localised impact and would not affect the overall integrity of the habitat in this area. As such, a Negligible impact is predicted for both benthos and fish species (including migratory fish) present, which is not significant. Bentonite Breakout Owing to variability in the prevailing geology, the risk of a surface breakout by bentonite drilling fluid cannot be negated completely. Bentonite will be used during the drilling operation to lubricate the TBM during microtunnelling during construction and will be pumped into the cuttings annulus during operations at the ambient pressure at the rock face. Should the TBM encounter voids within the formation (such as a fissure or weathered area of rock), material can be forced to the surface under pressure to create a breakout. In the littoral and sublittoral environments, the presence of bentonite at the surface can have a notable impact on sediment turbidity and suspended load. This increase in turbidity could result in increased siltation and the smothering of sediments and organisms accompanied by a reduction in the light available to the seabed for photosynthesis. High levels of suspended solids settling on the seabed can alter habitats, resulting in a potential loss of food resources for qualifying waterbird species of Baldoyle Bay SPA. Impacts of increased turbidity are likely to be minimal in the overall context of Baldoyle Bay, as the water depth is extremely shallow and the natural suspended sediment very fine. A release of bentonite may marginally increase the levels of some chemical components near the discharge. These may include some metals, although the components within the bentonite drilling fluid are naturally occurring and non-toxic to marine benthic fauna. A small quantity of this suspended clay escaping into the watercourse will produce a plume effect. In small quantities and areas of low tidal movement, the viscous high density clay will initially remain localised before becoming suspended and flushed out of Baldoyle Bay over subsequent tidal cycles. A bentonite release outside the Baldoyle Estuary will be exposed to a winnowing effect of the semi-diurnal tidal effects and wave action and will disperse into the water column within a very short period of time. This may create a localised plume of limited size and duration which may induce some avoidance behaviour by some ecological groups (i.e. fish and seals) within the area. Impact Overall, this is an unlikely occurrence and the potential impact would have a negligible magnitude and be for a short-term duration. This results in only Minor significance. Whilst the saltmarsh habitat is of very high ecological value, bentonite is unlikely to have any impact upon it if this occurs in the channel or open water environments, where this material will disperse harmlessly. If this occurs within the saltmarsh vegetation, then this material is unlikely to disperse quickly due to the lack of tidal flow in these areas, and may require some intervention to recover and disperse to avoid a smothering effect. However, as bentonite is naturally occurring and non-toxic to marine benthic fauna, and the water depth in Baldoyle Bay estuary is extremely shallow and the natural suspended sediment very fine, a small quantity of this suspended clay escaping into the watercourse would produce a negligible impact on benthic communities found within the bay. Consequently, the impact from a bentonite breakout, should it occur, would not affect the integrity of the habitat in this area. An expected short-

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term plume of increased fines within the estuary is also predicted to have a Negligible impact on the fish species (including migratory fish) present. Noise and Vibration Measurement Units and Background Tunnelling operations will produce low level noise emissions into the water column above the proposed outfall pipeline route (marine section). Whilst underwater noise is measured in decibels (dB), principally the same as airborne noise measurements, the reference pressure for underwater noise measurements is 1 micropascal (µPa) compared to the reference pressure for airborne noise of 20µPa. This has the effect of making the underwater decibel level (ref. 1µPa) approximately 26dB higher than that of airborne decibel level (ref. 20µPa) for the same sound pressure. Furthermore, airborne sound pressure levels are commonly quoted as ‘A’-weighted decibel levels. This means that care must also be taken when quoting or comparing dB levels, as the same pressure level can be represented in different ways. For example, a small boat (approximately 5m long) with an outboard engine is quoted as having a source level of 152dB re 1µPa (this is a nominal underwater sound pressure level at 1m from an idealised point source (Richardson et al. 1995)). On the basis of a crude propagation model using only hemispherical geometric spreading, the received underwater sound level at 25m is approximately 138dB re 1µPa, which is a sound pressure of 8Pa. This sound pressure in air is equivalent to approximately 112dB(A) re 20µPa, which is approximately a typical sound pressure level at an amplified rock concert (Kinsler et al. 1982). The point of the above comparison is that a boat is fairly loud, but that, taken out of context (e.g. if one were to compare the underwater source level of 152dB with standard comparison tables) one may erroneously suggest that underwater noise from a boat is louder than two jet engines at 30m. In tunnelling and microtunnelling, the TBM operates by slowly rotating a cutter head which will produce a low level ground vibration through the sediments and water column above the proposed outfall pipeline route (marine section). Different microtunnelling machines will rotate at different speeds. The likely vibration produced from a similar TBM in a shallow marine estuary has been compared to other projects (Sruwaddacon Bay, Co. Mayo, Hamburg to Elbe and Boston MWWST tunnels) which showed that the frequencies expected from the operation would typically range from 20Hz to 100Hz, but with a max peak of 400kHz. A maximum modelled sound pressure for the proposed outfall pipeline route (marine section) is expected to be approximately 100Pa (160dB re 1µPal) in the sublittoral zone, decreasing to less than approximately 30Pa (149.5dB re 1µPa) within a 30m distance from the TBM. This would be at a dominant frequency of 31.5Hz, but with 4Hz, 25Hz, and 63Hz outputs also significant frequencies. Outside of these, the responses would generally be below 10Pa (140dB re 1µPa). Measured frequency spectrums have actually shown this to be lower (Subacoustech 2014 pers.comm). Ambient subsea noise levels depend upon a number of factors, including wind/wave surface interaction, rainfall, and sound emitted from marine animals and shipping. Early studies into ambient noise levels (Knudsen 1948; Wenz 1962) determined relationships between descriptors of physical and anthropogenic noise sources (e.g. quantum of ships; wind speed) and the noise spectrum level produced. In shallow water (which includes the North Sea and the waters around Ireland), there is greater spatial and temporal variability in ambient noise level. Ambient noise levels would be expected to be higher in coastal locations due to the noise from breaking surf; the movement of shingle, sand, gravel and other sea/coast interactions; and from ships near ports, harbours and shipping lanes and smaller vessels. Thomsen et al. (2006) published results on the measurements of ambient noise around wind farms in the North Sea, with results showing a 1/3rd-octave spectrum typically peaking at just below 115dB re 1µPa at around 20Hz to 30Hz but falling to below 95dB re 1µPa above 250Hz (Diagram 9.6). Other common ambient background noises are quite natural and relate to the clicking of communicating crustacea (1kHz to 100kHz) or are anthropogenic and relate to fast-running outboard motors (152dB re 1µPa to

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156dB re 1µPa @ 630Hz to 6.3kHz) or slower-running fishing type vessels (151dB re 1µPa @ 250Hz to 1kHz). Vessel noise is broadband, ranging from 10Hz to 10kHz or more, and source levels can vary by vessel type from 157dB re 1µPa to 187dB re 1µPa for vessels traveling at 10 knots (Kipple and Gabriele 2007). Other ship borne devices, such as sonars and echo sounders, typically operate at 100kHz to 500kHz frequency in shallow water environments and are also large noise sources.

Diagram 9.6: Ambient Background Noise in the North Sea Shallow Water (Thomsen et al. 2006) The background noise levels were surveyed for the proposed outfall pipeline route (marine section) and the proposed marine diffuser location using a static recorder (LAB 2015). A single recorder was deployed throughout August 2015 and sampled at 16kHz in 24 bits and processed using third-octave band sound pressure level measurements over 10 second snapshots. The results showed that the impulse detector was being triggered almost continuously throughout the deployment by self-noise of the mooring system (possible vibration of the cables on the mooring). There was little or no noise recorded from biological sources (shrimp, bivalves or other animals), including cetaceans. The mean background noise level was approximately 105dB re 1µPa at 25Hz and 92dB re 1µPa at 2kHz. However, it is not possible to separate out the background from the self-noise signal, so a general background level of around 95dB re 1µPa at 2kHz is assumed. Microtunnelling using a Tunnel Boring Machine Noise levels from microtunnelling and TBM operations are created from a slowly rotating cutter head which will produce a low level ground vibration through the sediments and water column above the proposed outfall pipeline route (marine section). Different microtunnelling machines will rotate at different speeds but the likely vibration produced from a similar TBM in a shallow marine estuary, compared to other similar projects (Sruwaddacon, Hamburg to Elbe and Boston MWWST tunnels), typically produced 160dB re 1µPa in the range from 20Hz to 100Hz, but max peak decreasing to 149.5dB re 1µPa within a 30m distance from the TBM. Impacts on fish from noise and vibration from trenchless river crossings and coastal marine operations have been carried out for a number of similar projects (e.g. Felindre to Tirley Pipeline and the Uskmouth Pipeline), particularly in areas that relate to qualifying fish species and Annex II species (such as salmonids). BSL

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conducted a review of the potential impact of similar construction activities on Annex II fish species. Behavioural response to noise and vibration was related to the perceived loudness of the sound. In fish species, the sensation of ‘hearing’ can refer to auditory sensation both in the form of sensitivity to acoustic pressure or vibration from local particle velocity variations. The loudness of the noise and vibration is related to its level above the hearing threshold of a particular fish species. To assess perceived loudness, it is therefore a requirement that the auditory sensitivity of the species being assessed is known. A review of available fish hearing threshold data indicated that good quality audiograms are available for Atlantic salmon (Salmo salar) and trout, but that no data exist for anadromous species such as sea and river lampreys which have poor hearing due to their anatomy. As no species-specific data were available, Lampreys were assumed to have a poorer hearing response to salmonids due to their primitive anatomy, with minimum threshold hearing levels of 95dB re 1μPa, and to have a hearing response range from 30Hz to 400Hz. This information is summarised in Table 9.19.

Table 9.19: Hearing Threshold for Fish Species Found in Local Rivers (Parvin et al. 2007)

Species Surrogate Species Hearing Threshold Optimum Frequency Frequency Range (dB re 1 µPa) Atlantic salmon N/A 95 160Hz 30Hz to 400Hz

Trout N/A 115 100Hz 20Hz to 1,000Hz

Impacts on fish from noise and vibration can be gathered from the Subacoustech SPEAR model to predict approximate ranges of impact and effect from the noise sources using the dBht(Species) metric.

The likelihood of fish behavioural response to underwater noise and vibration was assessed using the dBht noise assessment metric. This compares the frequency components of the noise with the hearing threshold of the fish and provides a measure of dB above threshold (ht). On the basis of a large body of measurements of fish avoidance of noise (Nedwell et al. 2003; 2007), the following assessment criteria is proposed for assessing the potential impact of construction noise and vibration:

• 130dBht and over – Auditory injury threshold;

• 100dBht and over – 100% avoidance;

• 90dBht – Strong avoidance reaction by most individuals;

• 75dBht – Mild avoidance reaction occurs in a majority of individuals; and

• 0–50dBht – Low likelihood of disturbance. The studies presented a typical time history of the waterborne noise recorded at a position immediately above the 26” microtunnelling operation (River Tees) and the frequency spectrum of the underwater noise during drilling and non-drilling periods. The data have similar spectral levels over the frequency range from 80Hz to 100kHz. The data therefore indicate that the microtunnelling activity did not increase the ambient noise in the river over this frequency range. At very low frequencies, less than 80Hz, there is a marginal increase in the spectra levels. This is probably due to the variability of the background noise in the river at these very low frequencies, and may not be due to the microtunnelling. These data are presented on Diagram 9.7, in addition to published hearing thresholds for various species of fish (Parvin et al. 2007; Enger 1967; Hawkins and Johnstone 1978; Higgs et al. 2003; Nedwell 2006; Wahlberg and Westerberg 2005), as well as a background frequency spectrum of a similar TBM measured directly above the unit in a dry estuary (Nedwell 2013 unpublished). These data indicate that any

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waterborne noise from microtunnelling operation is generally below the hearing threshold (minimum perceived levels of sound) for the trout and salmon (also representing Lampreys). The data therefore indicate that the activity would be on the very limits of perception for these species. However, as the level will be less than 50dBht above the background threshold for the species, this perception is not likely to induce a behavioural response. As such, no significant adverse impact is expected. The study concluded that no risk of fish injury/fatality from microtunnelling, with only a short-term negligible behavioural response. A similar impact can be classified for the Proposed Project. It is worth noting that TBMs, if employed, do not always run a continuous operation, as segment lining is often required every 1m (approximately) with between 10 and 20 sections added each day. This will result in a temporary break in the progress of the TBM and introduce short temporary breaks in the noise profile history. Fish with swim bladders and specialised auditory couplings to the inner ear (e.g. goldfish, herrings) are highly sensitive to sound pressure, while fish with a swim bladder but without a specialised auditory coupling (e.g. cod) are moderately sensitive, and fish with a reduced swim bladder or lacking a swim bladder (e.g. dab ), mackerels, sharks, skates and rays) have low sensitivity (Fay 1988).

Diagram 9.7: Composite Figure of Microtunnelling and TBM Frequency Spectrum Compared to the Published Hearing Threshold for Various Fish Species (Composite from Parvin et al. 2007; Enger 1967; Hawkins and Johnstone 1978; Higgs et al. 2003; Nedwell 2006 and 2013 unpublished for the TBM frequency band; and Wahlberg and Westerberg 2005) Auditory thresholds, being the minimal level of sound that a fish can detect at a particular frequency 50% of the time, have been developed for a number of fish species. Auditory threshold curves for species that can be classified as having low, moderate and high hearing sensitivity have been included on Diagram 9.7. The highly sensitive group has a hearing threshold of less than 80dB re 1μPa. The moderately sensitive threshold is between 80 and 100dB re 1μPa, and those fish with a low sensitivity require noises greater than 100dB re 1μPa. These sensitivity thresholds were derived under quiet laboratory conditions. Therefore, thresholds under actual field conditions would be considerably higher, as the signal to noise ratio would have to be sufficiently high

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for sounds not to be ‘masked’ by the ambient, broadband noise levels produced by shipping, wind, currents or sediment movement. Vessel noise is broadband, ranging from 10Hz to 10kHz or more, and source levels for a variety of vessel types traveling at 10 knots range from 157 to 182dB re 1μPa (Kipple and Gabriele 2007). As sound waves propagate from the seabed, transmission loss occurs through geometric spreading as sound radiates outward from a source. This spreading loss causes sound levels to decrease in proportion to the square of the distance from the sound source. Sound loss for a specific site is dependent on bottom composition, bathymetric profile and other factors, but generally, spreading loss rates range from a 3dB to 6dB decrease per doubling of distance, and from 10dB to 20dB per 10-fold increase in distance. Other causes of sound loss include absorption by the water itself, and scattering due to air bubbles or suspended sediment. As a result of sound loss, fish located higher in the water column or located some distance away from the construction activity would be exposed to significantly reduced noise levels than a fish close to the source. For example, a fish located approximately 2m above the seabed and directly above the TBM exposed to a noise level of 60dB would only be exposed to noise levels of 40dB to 50dB at a distance of 20m from the same location. Fish have a ‘lateral line’ system that runs lengthwise down each side of the body and over the head. The lateral line consists of pressure-sensitive cells that convert subtle changes in water pressure into neural pulses that allow fish to avoid collisions, participate in schooling behaviour, orient to water currents, elude predators and detect prey. For most fish, the lateral line is only sensitive to low frequency (10Hz to 30Hz) (Popper and Fay 1993) near- field pressure changes, perhaps only as near as two body lengths or less (Palmer et al. 2005). Little is known about the sensitivity threshold of fish lateral line systems, but Voigt et al. (2000) found that the lateral line sensitivity threshold of eels to currents was approximately 0.5cm/s (0.2 inches/s). It appears that the sensitivity threshold of the lateral line system is limited to the area immediately surrounding a fish, and is approximately two orders of magnitude greater than the peak particle velocities that would be transmitted to the seabed from a subsurface tunnelling operation (such as a TBM). Fish would not be able to detect this degree of water movement with their lateral line system, and would not become disoriented or experience interference while foraging or sensing predators. The marine benthos is not affected by noise but will be exposed to ground vibration as the TBM travels below. The vibration output from the TBM at other similar tunnel construction sites has been modelled in the range of 0.1 to 0.6mm/s/metre of TBM diameter. Recent measurements of vibration above a very similar TBM in the west of Ireland has shown that the actual peak particle velocity was found almost an order of magnitude below this when the seabed was exposed (approx. 0.06mm/s to 0.12mm/s) (Nedwell 2014 pers.comm). This is far below a minimum action level of 2.5mm/s where this vibration can be perceived by passing fauna. This study was subject to an investigation by BSL (2014) on a similar segment lined tunnel in the west of Ireland. Results concluded that there was no significant impact to the benthos from the passage of a TBM. The geographical extent of the proposed TBM operations is limited to within 500m of the coast. No TBM operations are proposed within the Rockabill to Dalkey Island SAC, although qualifying species and other sensitive receptors may potentially encounter this area where TBM operations are proposed closer inshore. These impacts will vary with the sensitivity of the receptor. The baleen whales (mysticetes) which typically vocalise at very low frequencies (40Hz to100Hz) are not generally found in the shallow waters along the proposed outfall pipeline route (marine section) and therefore are not likely to be impacted by the Construction Phase. Of the toothed whales and dolphins (odontocetes), only the harbour porpoise and bottlenose dolphin, along with the seals (pinnipeds), are commonly recorded in the area. Table 9.20 summarises the typical auditory range for all of these species, although the sensitivity of these ranges may alter significantly with the frequency. Kastelein et al. (2002) showed that the sensitivity of the harbour porpoises (Phocoena phocoena) exhibited a very wide hearing

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range, with relatively high hearing thresholds at high frequencies but with a relatively poor hearing threshold of 92 to 115dB re 1µPa at the lower frequencies produced by the TBM. Hearing was notably more sensitive (i.e. lower thresholds) in the mid and higher frequency bands (60dB to 80dB between 1kHz to 8kHz, falling to only 32dB to 46dB from 16kHz to 140kHz, respectively). Consequently, noise output from the TBM below 100Hz is likely to be imperceptible to these cetaceans. The hearing sensitivity of the seals is marginally greater than that of the cetaceans at the lower frequency, with a central hearing range of around 8kHz to 16kHz, but with some infrasonic perception. However, the noise at a frequency of 75Hz would need to be at least 100dB to be perceived by the seal. Therefore, the impact of noise is also likely to be imperceptible to this group. Whilst the TBM vibrations might be at the very limit of the seals auditory range, the consequence of this is not expected to be significant. The majority of noise energy produced from the TBM operation in water is below 100Hz. The sensitivity of the high and mid frequency cetaceans along with the pinnipeds falls rapidly below 100Hz. Table 9.20 lists example criteria contained within Southall et al. (2007) which have been adopted by the Joint Nature Conservation Committee (UK) as suitable criteria to determine what constitutes an ‘injury offence’ in accordance with Article 12 of the Habitats Directive. The expected maximum noise outputs from the TBM is 160dB re 1µPa. This is below these limits for marine mammals in water. The vibration output from the TBM at other similar tunnel construction sites has been modelled in the range of 0.1 to 0.6mm/s/metre TBM diameter. Recent measurements of vibration above a very similar TBM in the west of Ireland have shown that the recorded peak particle velocity was an order of magnitude below this (approx. 0.06mm/s to 0.12mm/s) when the seabed was exposed above the tide. This level is far below a minimum action level of 2.5mm/s where this vibration can be perceived by passing fauna.

Table 9.20: Criteria for Injury (from Southall et al. 2007)

Animal Group Single Pulses Multiple Pulses Non-Pulse High frequency cetaceans

Sound pressure level 230dBpeak re 1µPa (flat) 230dBpeak re 1µPa (flat) 230dBpeak re 1µPa (flat)

2 2 2 Sound exposure level 198dB re 1µPa -s(Mhf) 198dB re 1µPa -s(Mhf) 215dB re 1µPa -s(Mhf)

Pinnipeds (water)

Sound pressure level 218dBpeak re 1µPa (flat) 218dBpeak re 1µPa (flat) 218dBpeak re 1µPa (flat)

2 2 2 Sound exposure level 186dB re 1µPa -s(Mpw) 186dB re 1µPa -s(Mpw) 203dB re 1µPa -s(Mpw)

Pinnipeds (air)

Sound pressure level 149dBpeak re 20µPa (flat) 149dBpeak re 20µPa (flat) 149dBpeak re 20µPa (flat)

2 2 2 Sound exposure level 144dB re 20µPa -s(Mpa) 144dB re (20µPa )-s(Mpa) 144dB re (20µPa )-s(Mpa)

Impact on Fish and Benthos The potential for impacts to the ecology through TBM noise is Negligible, based on an unlikely occurrence of negligible magnitude with short-term duration. Furthermore, it is concluded that neither fish (through sound) nor benthos (through vibration) would be aware of the TBM operation, although it is possible that tunnelling will be audible to selected fish species but of insufficient amplitude to provoke a behavioural response. Overall, it is concluded that the risk of fish injury/fatality from subsurface operations and behavioural response is classified as short-term and of Negligible significance.

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Impact on Marine Mammals Overall, the noise output from the construction of the microtunnelling to marine mammals (pinnipeds) and Annex II species is potentially short-term with negligible magnitude. Given their respective ecological value of medium to high, this impact is expected to be of Negligible significance.

9.4.3 Dredging of Proposed Outfall Pipeline Route (Marine Section) Suspended Sediments and Habitat Loss Marcon Computations International was commissioned to inform the potential spread and extent of suspended sediment plumes arising from dredging works associated with the construction of the proposed outfall pipeline route (marine section). The computational models used in this study were based on the MIKE3 coastal process software using the 3D hydrodynamic flow model and particle tracking (MIKE PT) modules. The model consisted of a regular 50m grid encompassing the general area within the proposed outfall pipeline route (marine section) and expanded out into a flexible mesh model of varying grid sizes. This particle tracking model used the hydraulic flow regime from the MIKE3 hydrodynamic model to simulate the transport and fate of material discharged to the water column. The model included variable graded material along with temporally and spatially varying discharges. The outfall will be constructed using a combination of a backhoe dredger in shallower areas, and a trailer suction hopper dredger (TSHD) where the water depths are beyond the limits of the backhoe dredger. The backhoe dredger or similar will be used for the dredging activity during 12-hour operations, which gives a maximum dredging quantity of about 78m³ per hour while the dredger is working. It is estimated that the total volume of material to be excavated ranges between 200,000m3 to 400,000m3 and that the dredging operation will take approximately six months. Details of the sediment characteristics were obtained from the surface and sub-surface sediments along the proposed outfall pipeline route (marine section) from the vibrocoring and borehole data, with calculations based on their proposed excavation locations along the proposed outfall pipeline route (marine section) (i.e. BH03, BH05 and BH08). These samples showed that sediments ranged from grey silty sand to grey sandy gravel. Whilst grey silty sand predominates along the entire proposed outfall pipeline route (marine section), the increase in gravel fraction over depth and towards the offshore end of the trench have largely been ignored for suspended sediment dispersion purposes, as the heavier fractions settle out within a few metres of the dredger. Material losses through suspension in the water column were assumed to be conservative 10% of total dredged volume, representing a 7.5% loss at 1m above the seabed and a 2.5% loss at 1m below the surface. The MIKE model simulates the fate of the loss of material from the dredgers by releasing particles into the water column and tracking each particle throughout the simulation process. A range of grain sizes was used in order to cater for the variation in sediment grading of the bed sediment material. Assuming a density of 2,000kg/m3 for in-site consolidated sand/gravel mix, the extraction rate equates approximately to 1,852kg/s and a 10% loss of 185.2kg/s occurring through sediment suspension. A dredging simulation was then run over the full excavation period with the origin for dispersion and the source of the material moved to keep track with the dredgers’ simulated progress along the route. The results of the dredging simulations were shown graphically by a series of model output diagrams based on operations from different borehole locations or different states of the tide. These have been summarised into a single chart (refer to Figure 9.6). At almost all locations, snapshots of suspended sediment concentrations were taken over the course of spring or neap tides, with the majority observed within the 0mg/l to 100mg/l range. In only two of the snapshots were the suspended sediment concentrations predicted to be greater than 100mg/l. The

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deposition depth of dredged material is greatest in the immediate vicinity (within 8m) of the trench (>300mm) with deposition depths reducing to less than 3mm within a few hundred meters of the trench route. The spread of the sediment plume shows the controlled release of spoil material by hopper barge every seven hours producing a northerly plume drifting away from Ireland’s Eye, with the greatest plume concentration recorded in the shallower first 2km of the route from landfall. The highest concentrations of suspended sediments >10 g/l were recorded at bed level within 50m to 100m from the discharge point. The granular nature of these sediments results in a fast settlement of material to the bottom, with seabed and mid-depth concentrations generally falling to below 1g/l within 200m from the discharge. Lower levels of sediment fines (silts and clays), recorded in the sub-surface layers of the corridor are modelled to travel further on discharge, and with concentrations of between 10mg/l and 100mg/l recorded out to a maximum distance of around 1,400m north of the route. Most suspended material would be recorded just above bed level concentrations in the surface waters generally limited to discharges made only in the offshore half of the proposed route. Here, low level concentrations of between 5mg/l and 10mg/l were recorded out to 1,500m from the corridor or remained just detectable out to 2,600m. With the exception of a small surface plume of 1mg/l to 5mg/l and 200m to 300m across caught in a small back-eddy 350m north of the Ireland’s Eye, all of the plume discharge is predicted to disperse to the north of the proposed outfall pipeline route following a controlled discharge. None of the discharged sediment is predicted to impact the qualifying Annex I habitats of littoral and sublittoral reef features of the Rockabill to Dalkey Island SAC along the north and eastern coastline of Ireland’s Eye. Suspended sediments throughout the remainder of the SAC were limited to near bed impacts in the main part of the SAC area. Scientific investigations of these features in 2015 identified diverse biological populations, consistent with this habitat type and area. However, no species of particular conservation interest were noted during the studies with no rare or particularly fragile biotopes recorded. The natural siltation levels were high in the sublittoral environment, a fact that has not appeared to have had a significant impact to the biological diversity around Ireland’s Eye. Whilst siltation levels are already high in the sublittoral environment, a significant increase in suspended sediment over a prolonged period, particularly during the summer months during peak algal growth, potentially could have an adverse impact on the algal biotopes present through reduced light penetration and availability. However, this limited exposure to high turbidity will be limited due to the short period of dredging. The precise tidal state and lunar cycle required to transport this material to the south (i.e. ebbing during spring tides) and the moderately strong tidal currents experienced in this area will also reduce the likelihood of deposition of significant silt material on these reef habitats, the resultant degradation of the sublittoral benthic biotopes through smothering and the burial of the infralittoral and circalittoral communities. Sediment plumes from the discharge of dredge spoil may present habitat disturbance to local cetacean foraging in the area. The combined surface and seabed plume created during the dredging process recorded a maximum area with elevated suspended sediment above 5mg/l of 4.5km2, of which approximately 1.5km2 is currently within Rockabill to Dalkey Island SAC. This is equivalent to only 0.55% of the total SAC area (of 273km2). The duration of the dredging within the SAC is expected to be 60 days. This plume is expected to have a temporary but localised impact on the foraging behaviour of the visual hunters such as seals and harbour porpoise due to the reduced visibility near the dredging. It should be noted that the noise created during the dredging in the waters surrounding the dredgers is likely to induce avoidance behaviour by these species prior to species encountering the discharge plume itself. The harbour porpoise feeds mainly on small shoaling fish, such as herring, but may also feed upon prey taken at or close to the benthos. As harbour porpoises use a series of high frequency clicks for echo-location during navigation and hunting, they are less susceptible to the impacts of suspended sediment plumes during foraging and are routinely found in inshore areas of high natural turbidity (e.g. southern North Sea, Liverpool Bay in the Irish Sea).

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When not feeding, the impact of the plume on other visual hunters, such as migratory fish species and pinnipeds, is likely to induce an avoidance reaction. There is also a potential to encourage predation within the plume, where fish feed on suspended benthos and the seals feed upon the fish. The size of the plume into the area surrounding the SAC is not likely to be significant at any given time, and the area negligible when compared to the potential foraging range of pinnipeds from the Lambay Island SAC. Seals are expected to show a simple avoidance reaction if a plume is encountered. The maximum concentration of the plume is predicted to be around 50mg/l near the surface, which is approximately within the range expected for natural suspended sediment loads recorded near the proposed marine diffuser. The duration of the dredging is expected to take 60 days, and analysis of the pre-dredged sediments results indicated natural uncontaminated sediments throughout the route based on the samples analysed. Overall, the impact to Annex II species from Lambay Island SAC from the construction dredging plume will be negligible, although this may introduce minor behavioural changes for the short construction period. As the direct impact by the plume will be very localised (within 1,500m of the source), short-term (<60 days) and will not deteriorate any resources within the range of the species. The magnitude of impact on migratory fish (such as salmonids) and pinnipeds is expected to be low and very short-term. Given the medium ecological value of these species, it is considered that this will be of Minor impact significance. The area of the proposed outfall pipeline route (marine section) is considered a low intensity spawning and nursery ground for sandeel, and whilst local populations may potentially be affected by habitat loss and disturbance through sediment excavation and deposition during dredging and trenching activities (Ellis et al. 2010; 2012), this is likely to have a minimal impact to the wider Irish Sea population. The ecological value for fish and shellfish spawning with regards to dredging is considered low. The magnitude is negligible due to the small scale of the Proposed Project and the low intensity nature of the demersal spawners, and the duration of impact is anticipated to be short-term (up to five years). Most mobile adult and juvenile fish (including herring) are able to avoid the impacts of physical disturbance and habitat loss by moving to adjacent areas (Wenger et al. 2017). The impact of dredging/trenching is therefore anticipated to be low for most species. Sandeel, as a generally sedentary species, may be less able to avoid physical disturbance than others, particularly after spawning when they reportedly remain in their burrows for approximately two months. Their specific substrate requirements are very limiting to their distribution, hence the renowned patchiness. They have been found to be adversely affected in areas with sediment containing >2% silt. Dredging and temporary storage of dredged materials on the seabed may cause smothering of sandeel habitat, and could potentially affect the local substrate composition through disturbance of the seabed and potentially increasing suspended sediment concentrations. Overall, the sandeel effect-receptor interaction is expected to be low. Adult and juvenile sandeel are considered to be of medium vulnerability and high recoverability, and may be of regional importance in terms of a prey source. Cod are nationally important and considered in decline, and as such are subject to recovery measures (Cod Recovery Plan). There is a high intensity cod nursery near the proposed outfall pipeline route (marine section) (Ellis et al. 2010), and several specimens were recorded during the inshore fisheries assessments carried out in 2015 and 2017 (ASU 2017). For these reasons, cod have been assessed as of high ecological value. However, the magnitude of the impact is considered negligible due to the small footprint of the Proposed Project, and the impact duration is expected to be very short-term. Therefore, the likely effects are insignificant. Disturbance to the marine benthos and the sand dwelling shellfish (such as the razor clam) are expected to be high, although this will be limited to a relatively small area directly relating to the trenched route (approximately

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0.16km2), or neighbouring sediments (approximately 1km2) affected by localised smothering of stored or plume- dispersed material. The area is routinely disturbed by clam dredgers and routinely repopulates the substrates within the short-term. The benthos may be impacted by dredging activities as a result of the physical removal of substratum and associated organisms from the seabed along the path of the dredge head, and the subsequent deposition of material through side casting or settlement of a dispersed plume of suspended sediment. A review of the impact of aggregate dredging in European coastal waters suggests that marine communities conform to well-established principles of ecological succession, and that these allow some realistic predictions on the likely recovery of benthic communities following cessation of dredging (Newell et al. 1998). In general, communities living in fine mobile deposits, such as that occur in estuaries, are characterised by large populations of a restricted variety of species that are well adapted to rapid recolonisation of deposits that are subject to frequent disturbance. Recolonisation of dredged deposits is initially by these ‘opportunistic’ species, and the community is subsequently supplemented by an increased species variety of long-lived and slow-growing ‘equilibrium’ species that characterise stable undisturbed deposits such as coarse gravels and reefs. Rates of recovery reported in the literature suggest that a recovery time of six to eight months is characteristic of many estuarine muds where frequent disturbance of the deposits precludes the establishment of long-lived components. In contrast, the community of sands and gravels may take two to three years to establish, depending on the proportion of sand and level of environmental disturbance by waves and currents, and may take even longer where rare slow- growing components were present in the community prior to dredging. As the deposits get coarser along a gradient of environmental stability, estimates of five to 10 years are probably realistic for development of the complex biological associations between the slow-growing components of equilibrium community characteristic of reef structures. The benthos along the proposed outfall pipeline route (marine section) are based predominantly on sands, particularly in the western inshore section of the proposed outfall pipeline route (marine section). Here, the water depth is very shallow and subject to continuous reworking by wave induced currents. The central part of the proposed outfall pipeline route (marine section) is a silty sand, becoming increasingly coarser towards a muddy sandy gravel near the proposed marine diffuser location. There is an absence of any developed biogenic or geogenic features with any significant epifaunal component. The physical recovery of the surface sediments along the proposed outfall pipeline route (marine section) is expected to show recovery within a few months, with a recolonisation by the benthos to occur within six months for the majority of species, but possibly one to two years for some the of larger slower-growing taxa. Impact The potential impacts on Annex I reef habitats within the Rockabill to Dalkey Island SAC from the dredging plume will be short-term with negligible magnitude. Based on a very high ecological value, this would have an impact of Minor potential significance on this qualifying habitat. The impact of a suspended sediment plume to the Annex II species recorded within the Rockabill to Dalkey Island SAC, in particular the harbour porpoise, is expected to be short-term, and of negligible magnitude. Based on a very high ecological value, this would also have a Minor impact significance. The potential for impacts to non-migratory fish and shellfish areas from the dredging plume or habitat loss will be spatially limited to a small area, short-term, with low magnitude and are therefore of Negligible significance. The impact to benthos is also expected to be short-term, localised and of low magnitude arising from the plume with a negligible magnitude for loss of habitat. The overall significance of these impacts will also be Negligible.

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Noise and Vibration The noise created by backhoe dredgers is produced from a repetitive sequence of sounds generated by winches, bucket impact with the substrate, bucket closing, and bucket emptying (Dickerson et al. 2001; Robinson et al. 2012). Grab and backhoe dredgers are also characterised by sharp transients from operation of the mechanical parts. Suction dredgers produce a combination of sounds from relatively continuous sources, including material passing through the suction pipe and the drag head moving across the substrate. However, it is the noise of the support vessels (engine and propeller noise) that can often be the most significant source of noise. Noise levels produced by a backhoe dredger operating around the Shetland Islands, UK, were recorded by Nedwell et al. (2008). They recorded a calculated source level of 163dB re 1 Pa at 1m (bandwidth = 20Hz – 100kHz), although Reine et al. (2012) calculated source levels of 179dB re 1µPa at 1m (bandwidth = 3Hz – 20kHz). Noise produced by suction dredgers has been measured on a number of occasions. Robinson et al. (2011) measured six trailer suction hopper dredgers, finding that the sound levels recorded below 500Hz were in line with those expected for a cargo ship travelling at modest speeds (8–16kn). The maximum broadband source was 189.9dB re 1µPa at 1m (calculated based on a bandwidth 31.6Hz to 39.8kHz). Estimated source levels above 1kHz were relatively high, probably a result of the coarse aggregate pumped through the dredge pipe. Using an identical approach, de Jong et al. (2010) found very similar results to Robinson et al. (2011), with source levels recording a decline beyond 1kHz when dredging sandy rather than gravel sediments. Consequently, the variation in sediment types from sands to mixed gravels encountered along the proposed outfall pipeline route (marine section) is expected to alter the source levels during dredging, particular at the higher frequencies at the eastern end of the proposed outfall pipeline route (marine section). A collation of dredger related noise profiles was carried out by Subacoustech Environmental using their SPEAR model based on measured recordings retained within their database. The SPEAR model gives unweighted source levels of 186dB re 1µPa for suction dredgers and 165dB re 1µPa for backhoe dredgers. Therefore, the predicted noise from suction dredgers is expected to be approximately 20dB above that of backhoe dredgers, which is due largely to the typical size difference between the two types of vessel operating the dredging equipment as well as the increased size of plant necessary for suction dredging. A model of expected underwater noise created during the dredging exercise was based on Parvin (2008) and Robinson et al. (2011) and estimated at 188dB ref 1μPa in the 50Hz to 89kHz range. The output using third-octave bands of 125Hz, 1kHz and 8kHz were calculated to range between 172dB and 176dB ref 1μPa. The contouring of sound exposure levels from a source along the proposed outfall pipeline route (marine section) at these three frequencies showed a propagation of sound to a sound exposure level of around 100dB re 1µPa, within 1km at 125Hz, around 30km for 1kHz and 12km for 8kHz. When assessing impacts to cetaceans, knowledge about the hearing range of species is not fully understood, although it is assumed that whales and dolphins hear over similar frequency ranges to the sounds they produce, noting that hearing ranges can extend beyond that of frequencies used for vocalisations (Southall et al. 2007). If anthropogenic noise, such as that produced during dredging operations, coincides with species' hearing ranges, it has the potential to affect individuals and populations of marine mammals present within the area at the time. Table 9.21 summarises the typical auditory range for all of these species, although the sensitivity of these ranges may alter significantly with the frequency. Based on these criteria, the majority of sounds produced by dredgers will be at frequencies within the lower frequencies of the cetacean’s auditory range. The noise levels expected from the dredging activities during the Construction Phase are not expected to be sufficient to cause any damage, but may alter the species behaviour either through avoidance or curiosity.

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Table 9.21: Auditory Range of Qualifying and Sensitive Receptors in the Proposed Outfall Pipeline Route (Marine Section) Location

Species Of Marine Vocalisation Frequency Expected Residency Criteria for injury (from Southall et al. Mammal Range in Construction Area 2007)

Whistles 2–18kHz Common dolphin Clicks 8–14kHz Rare (Delphinus delphis) Barks <0.5–3kHz

Whistles 0.8–24kHz Sound pressure: 230dBpeak re 1µPa (flat) Bottlenose dolphin Clicks 0.2–150kHz 2 Common Sound exposure: 198dB re 1 µPa -s(Mhf) (Tursiops truncatus) Barks 0.2–16kHz Low freq. 0.05–0.9kHz Whistles 2–18kHz Harbour porpoise Clicks 8–14kHz Frequent (Phocoena phocoena) Barks <0.5–3kHz Common seal In water: Common (Phoca vitulina) Sound pressure: 230dBpeak re 1µPa (flat) 2 Sound exposure: 198dB re 1µPa -s(Mhf) Various ~0.05–100kHz Grey seal Common In air: (Halichoerus grypus) Sound pressure: 230dBpeak re 1µPa (flat) 2 Sound exposure: 198dB re 1µPa -s(Mhf) Impact on Marine Mammals The noise from dredging activities during the Construction Phase on marine mammals and Annex II species is expected to be short-term and of negligible magnitude. The duration of the dredging phase of the work is expected to be six months, although the actual duration of the dredging activity is expected to be much shorter. The overall significance of impact is therefore Minor for harbour porpoises (within the SAC) but Negligible for other cetaceans and pinnipeds. Impact on Fish The abundance of fish recorded within the area is not expected to be high, although there is a high diversity of species for the area. Whilst these do not constitute a population of significant commercial interest, they may represent an important food source for the sea birds and species related to the surrounding SPA (see Section 9.4.2 and Chapter 10 Biodiversity (Marine) in Volume 3 Part A of this EIAR). As with the construction noise during tunnelling, impacts on fish from noise and vibration from dredging operations can also be gathered from the Subacoustech SPEAR model to predict approximate ranges of impact and effect from the noise sources using the dBht(Species) metric.

A summary of SPEAR dBht impact threshold and the effect of noise on common marine species is outlined in Table 9.22.

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Table 9.22: Impact Distances Based on Strong (90dBht) or Mild (75dBht) Avoidance Behaviour of Four Common Fish Species (Subacoustech SPEAR dBht(Species) metric)

Fish Species Cod Dab Herring Salmon

Dredger type 90dBht 75dBht 90dBht 75dBht 90dBht 75dBht 90dBht 75dBht

Backhoe dredging <1m 3m <1m 1m 1m 4m <1m <1m

Suction dredging 7m 39m 1m 7m 13m 65m 1m 5m

At levels of 90dBht a strong avoidance reaction is expected in virtually all individuals, whilst at levels of 75dBht some avoidance reaction is expected by the majority of individuals. However, habituation or context may limit the effect over longer operational periods. All the predicted noise levels for the Proposed Project are well below the auditory injury criteria of 130dBht. The predicted impact ranges are very low and, at most, extend out to a few tens of metres. This is because of the relative low level of noise produced by the dredging vessels and that the noise from these vessels while in operation tends to be higher in frequency than most fish can perceive. Consequently, this model concluded that the risk of fish injury/fatality from dredging and behavioural response is classified as short-term and of negligible magnitude. Overall, the noise output from construction dredging on fish species (including migratory fish which have a medium ecological value) is expected to be short-term, and the impact significance is expected to be Negligible. Pollution Other than the small risks relating to pollution emissions connected with all marine vessels, the operation of dredging does not introduce any pollutant components into the environment. The main impact from dredging relates to the resuspension of seabed material into the water column and transported away from the site in a suspended sediment plume. The spread and concentration of the dredging plume and its potential interaction with qualifying features in the Rockabill to Dalkey Island SAC is summarised in Figure 9.6 Maximum Suspended Sediment Plume Concentrations Arising from Dredging over the Duration of Dredging Works for the Proposed Outfall Pipeline Route (Marine Section) . The dredged material within this plume was analysed for both natural and historical anthropogenic contaminants from the surface and sub-surface sediments (and summarised in Section 9.3.3). Results indicated natural uncontaminated sediments throughout the sediments tested. Impact The impact from pollution during dredging on immediate marine ecology (marine mammals, passing fish species and surrounding benthos) will be short-term and of negligible to no magnitude, and therefore the likely impact significance is expected to be of Negligible to Minor significance.

9.4.4 Piling for Tunnel Interface and/or Fibre Optic Cable Noise and Vibration The construction of the interface between the initial section of the microtunnelling and the dredged area may require sheet piling or an installation of a caisson during construction. Furthermore, sheet piling may also be required during operations to cross the existing fibre optic cable during the proposed outfall pipeline route (marine section) installation. The noise impact from these operations would be significant. Whilst both of these areas are

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located outside of SACs, qualifying species relating to the Rockabill to Dalkey SAC (i.e. harbour porpoises) or other potentially sensitive receptors including migratory species (such as salmonids) or mobile species from other nearby designated sites (i.e. pinnipeds) may be exposed to potentially harmful noise levels during this phase of the construction. The same acoustic model was used to assess the noise impact from an impact hammer source that might be used at the tunnel interface or at a telecom cable crossing, midway along the proposed outfall pipeline route (marine section). The source was based on a piling of 600mm with the sounds generated impulsively. In order to translate the potential impacts more accurately, the sound exposure level is expressed as ‘dB 1μPa²@1m’, which corresponds to the acoustic energy received integrated over a given frequency band and over the significant duration of the sound pulse (100ms in this study; De Jong et al. 2008). At two of the same lower third-octave bands used for the dredging assessments, the sound pressure level of the piling was estimated to be 186dB 1μPa²@1m at 125Hz, dropping to 172dB 1μPa²@1m at 1kHz. Contouring of sound exposure levels from a source along the proposed outfall pipeline route (marine section) at these two frequencies showed a propagation of sound to a sound exposure level of around 100dB re 1µPa, within 2km at 250Hz, and around 12km for 1kHz. Impact The noise output from piling during construction of the proposed outfall pipeline route (marine section) interface or fibre optic crossing point could have a potential impact on fish, including salmonid species. Both of the possible areas of operation are within an open water environment and would induce an avoidance reaction in these mobile species. Consequently, the impact magnitude is considered to be low with a likely significance of Negligible (marine fish) to Minor (salmonids). Pinnipeds and cetaceans are of a medium to high ecological value, given their proximity to nearby SACs where they represent qualifying species. This results in a Minor significant impact. Further mitigation to monitor for the presence of these species during these activities will be required.

9.4.5 Installation of the Proposed Marine Diffuser Habitat Loss/Disturbance The construction of a marine riser is required to make the hydraulic connection between the outfall pipeline and the seabed and is necessary to discharge the treated wastewater from the proposed outfall pipeline route (marine section) at the discharge point. The diffuser section consists of one or more vertical riser pipes which are attached to the marine outfall pipeline after it is lowered into the trench. The actual diffuser valves (Tideflex duckbill valves or similar) are then attached to the riser pipes. The remaining structure will have a direct impact on the seabed, but this is anticipated to be a very small footprint. Whilst this is located within the Rockabill to Dalkey Island SAC, there are no qualifying interests in this area of impact relating to the seabed. Impact Overall impact to the benthos will be permanent but expected to be of negligible magnitude and Negligible significance. Noise and Vibration The proposed marine diffuser will have a diameter of 2m and be positioned 2m above the seabed, with four 400mm diameter ports arranged concentrically. The final method of construction for the riser will be mounted/installed during assembly of the concrete ballasts in the final outfall section. This section will then be

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sunk into position by controlling the flooding of the pipe using divers. This will result in no additional noise impacts at the proposed marine diffuser location other than those already present from the activity of vessels during the Construction Phase. Currently, no piling is anticipated within the Rockabill to Dalkey SAC. Impact The noise impacts from the construction of the proposed marine diffuser (as part of the dredging operation) on marine mammals and Annex II species is expected to be less than that of the dredging activities. The operation will be short-term and of negligible magnitude and therefore Minor significance A summary of the construction impacts on marine ecology is shown in Table 9.23.

Table 9.23: Summary of Impacts During the Construction Phase on Marine Ecology

Activity Impact Receptor Ecological Value Magnitude Duration Significance

Benthos Negligible Negligible Short-term Negligible

Noise/vibration Fish species Low to medium Negligible Short-term Negligible

Otter Low Negligible Short-term Negligible

Construction of Benthos Negligible Negligible Short-term Negligible compounds Fish species Low to medium Negligible Short-term Negligible Pollution Marine Medium to high Negligible Short-term Negligible mammals Otter Low Negligible Short-term Negligible Saltmarsh Very high Negligible Short-term Minor habitat Air breakout Medium to Benthos and fish Negligible Short-term Negligible negligible Saltmarsh Very high Negligible Short-term Minor Bentonite habitat Microtunnelling below breakout Medium to Benthos and fish Negligible Short-term Negligible Baldoyle Estuary negligible Medium to Benthos and fish Negligible Short-term Negligible negligible Noise and Pinnipeds Medium Negligible Short-term Negligible vibration Harbour High Negligible Short-term Negligible porpoise Benthos Negligible Low (short range) Short-term Negligible Migratory fish Medium Low (short range) Short-term Minor and pinnipeds Other fish Suspended species and Low Low (short range) Short-term Negligible sediment plume shellfish Reef habitat Very high Negligible Short-term Minor Dredging of proposed (SAC) outfall pipeline (marine Harbour Very high Negligible Short-term Minor section) porpoise (SAC) Medium to Loss of habitat Benthos and fish Negligible Short-term Negligible negligible Pinnipeds Medium Negligible Short-term Negligible Noise and Harbour Very high (SAC) Negligible Short-term Minor vibration porpoise Fish species Low to medium Negligible Short-term Negligible

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Activity Impact Receptor Ecological Value Magnitude Duration Significance All marine Negligible to very Negligible to Pollution Negligible to none Short-term species high Minor Salmonids and Negligible to other fish Low to medium Low Short-term Minor Tunnel interface using species piling and/or caisson Noise and Pinnipeds Medium Low Short-term Minor installation (outside the vibration SAC) Harbour porpoise and High Low Short-term Minor dolphins Installation of Habitat loss Benthos Negligible Negligible Permanent Negligible proposed marine diffuser (inside the Noise and Harbour Very high (SAC) Negligible Short-term Minor SAC) vibration porpoise

9.5 Impact of the Proposed Project – Operational Phase Impacts during the Operational Phase relate to the presence of infrastructure in the marine environment and the potential for changes to water quality. For the operation of the proposed outfall pipeline route (marine section), the dilution rates and area of plotted plume dispersion are discussed in detail in Chapter 8 Marine Water Quality. The expected levels of suspended solids and nutrient emissions during the Operational Phase of the Proposed Project can have a direct impact on the marine ecology near the proposed outfall marine diffuser. Following results from the three-dimensional hydrodynamic modelling studies, the final treated wastewater produced at the new proposed WwTP would conform to the standards outlined in Table 9.24.

Table 9.24: Final Target Treated Wastewater Emission Limits for the Proposed Wastewater Treatment Plant

Parameter Emission Limit

95th Percentile Not to Exceed

pH 6–9

Temperature 25°C (max)

Biological Oxygen Demand (BOD5) 25mg/l O2 50mg/l O2

Chemical Oxygen Demand 125mg/l O2 250mg/l O2

Total suspended solids 35mg/l 87mg/l

Note: BOD5 on a five-day test The dispersion of the treated wastewater from the proposed marine diffuser when discharged is expected to be significant in the near field mixing zone. The water quality is expected to reach standards set out in the Water Framework Directive, European Communities Environmental Objectives (Surface Waters) Regulations 2009 (S.I. No. 272 of 2009) and Directive 2006/7/EC of 15 February 2006 concerning the management of bathing water quality (Bathing Waters Directive) to maintain a ‘good’ water quality status set out for ‘coastal’ waters and to prevent impact to nearby bathing waters or protected areas (such as shellfish waters). For peak flow, the European Communities Environmental Objectives (Surface Waters) Regulations 2009 set out a DIN limit of 0.25mg/l, a Molybdate Reactive Phosphorus limit of 0.04mg/l (for transitional waters, as no standard is set for coastal), Biochemical Oxygen Demand of 4.0mg/l and Escherichia coliform (COLI) counts of <500 per 100ml (95th

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percentile). The model showed that, with the exception of DIN immediately within the near-field mixing zone, the compliance levels within the plume or of the surrounding waters were not compromised. Details of the plume discharged into the Irish Sea by the proposed outfall pipeline are discussed in Chapter 8 Marine Water Quality in Volume 3 Part A of the EIAR, and the standards of the treated wastewater are summarised above and characterised in Table 9.24. The proposed outfall marine diffuser is designed to enhance the dilution of the treated wastewater into the receiving waters on discharge. A numerical model of the expected dilution was produced based on the Cornell Mixing Zone Expert System (CORMIX) to predict the near-field dilution characteristics of a proposed outfall discharging to the receiving waters. The CORMIX model predicted the plume development, dilution and treated wastewater concentrations within the plume. Near the discharge port, the plume tends to behave as a coherent jet, dominated by its initial momentum and buoyancy. Eventually, these are dissipated by interaction with the surrounding medium, and the plume becomes a diffuse mass carried along by the ambient current. Mixing initially occurs by turbulent flows at the boundaries of the plume, and later primarily by pure diffusion processes. Simulations were run using the CORMIX using hydrodynamic data applied for the tidal cycle, ambient water quality and structure and profiled currents recorded during an earlier survey campaign at the proposed outfall pipeline route (marine section). Hourly simulations were carried out over the full tidal cycle for both neap and spring tidal scenarios, with results indicating a consistent 20-fold dilution recorded within the near field (50m) from the discharge point on both neap and spring tidal streams. Far-field dilutions (500m) showed greater variability based on the tides but generally varied from a 33-fold dilution during slack events to 100-fold dilution during mid flood or ebb tidal streams. Therefore, for total suspended solids, a 35mg/l (95th percentile) discharge would therefore dissipate to an increased background of 1.75mg/l within 50m at all states of the tide, but vary from 1.06mg/l to 0.35mg/l at 500m, subject to tidal stream. Habitat Loss/Disturbance Long-term observations of turbidity recorded at the proposed marine diffuser location throughout 2015 and 2016 (TechWorks 2016) indicated a variable ambient suspended sediment load ranging from 4mg/l to 120mg/l calculated from converted turbidity measurements (using Guillen et al. 2000) or 15mg/l to 160mg/l from sampled water quality measurements taken throughout the same survey period. The longer-term observations in turbidity revealed a significant variability in water clarity by season as well as by tidal state, with a regular semi-diurnal pattern recorded over a slow seasonal decrease in turbidity (i.e. increased water clarity) recorded during the summer months. Spring and neap tidal cycles had a marked effect on the suspended sediment load, increasing ambient levels by between 7mg/l and 25mg/l during the stronger spring tidal flows. Ambient suspended sediments were also affected by strong winds and poor weather periods. No loss of pelagic habitats is predicted due to the level of treatment being applied to the outfall discharge where a maximum suspended sediment load of 35mg/l will be applied (95th percentile). As noted above, this is currently within the range routinely recorded for suspended sediments at this water mass and would be expected to disperse with the ambient seawater by a factor of 20 within 50m on discharge. Whilst this discharge is expected to provide a localised plume visible to marine mammals, particularly for visual hunters (such as pinnipeds), at certain times of the year, the presence of the plume is not expected to have a direct effect on the presence of harbour porpoises, as this species is routinely found in high turbidity shallow waters. However, both seals and porpoises may be attracted to the proposed marine diffuser in search of prey species, which themselves might be attracted to the increased productivity surrounding the outfall discharge. Details of the treated wastewater discharge qualities modelled during the Operational Phase are outlined in Table 9.24. Results indicate that the plume created by the treated wastewater discharge will be subject to significant

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dispersion, with a 20-fold dilution achieved within 50m of the diffuser and between a 33- and 100-fold dilution within 500m of the diffuser. Based on a maximum suspended sediment load of 89mg/l, a worst case scenario would show a minimum dilution rate of 33 fold within 500m of the diffuser. This is an increase of only 2.7mg/l above a minimum background concentration of between 4mg/l and 15mg/l. This is an almost imperceptible increase in the background turbidity at this distance. The majority of treated wastewater diluting to below 5mg/l will occur within 50m of the outfall. A radius of 500m is equivalent to an area of approximately 0.2km2 or 0.07% of the total SAC area. Discharge modelling shows that the resulting suspended sediment plume discharged from the proposed marine diffuser will disperse away from the site following a trajectory north and east of the Ireland’s Eye coastline. This will therefore not impact on the sublittoral reef area recorded on the northern and eastern parts of this island within the Rockabill to Dalkey Island SAC. Impact The impact of the discharged plume into the Rockabill to Dalkey Island SAC will be long-term (the lifetime of the outfall discharge). However, the magnitude of this impact is expected to be negligible for the Annex II designated species, harbour porpoise, as this area constitutes a small fraction of the animal’s habitat range, and would be imperceptible above background conditions for the majority of the time with no significant effect on the animals foraging ability or behaviour. Therefore, it is considered that the likely impact significance is Minor. The plume is also unlikely to impact the designated sublittoral reef features within the SAC as the plume is predicted to disperse and dissipate away from these locations. Therefore, with no magnitude of impact, the predicted significance of this impact will be none or Negligible.

Pollution All discharges to the aquatic environment from sewerage systems owned, managed and operated by water service authorities require a wastewater discharge licence or certificate of authorisation from the EPA. This authorisation process provides for the EPA to place conditions on the operation of such discharges to ensure that potential effects on the receiving water bodies are limited and controlled, with the aim of achieving good surface water status and good groundwater status. The proposed WwTP will require a wastewater discharge licence to be granted by the EPA under the Waste Water Discharge (Authorisation) Regulations 2007 (S.I No. 684 of 2007) prior to commissioning.

Impact The risk of an impact by pollution from the discharge plume will be long-term (the lifetime of the outfall discharge). However, the magnitude of this impact is expected to be negligible based on the standards applied to the discharge from the proposed WwTP. Furthermore, the dispersion qualities predicted by the model show that, should a problem occur and the discharge fails to meet the criteria outlined in the regulations, levels will dissipate quickly from the diffuser. Consequently, the predicted significance of this impact will be none or Negligible. Benthos and Reef The potential impacts on the benthos near the proposed marine diffuser are expected to be low, as a result of increased nutrient enrichment through elevated primary productivity. The marine benthic macroinvertebrate communities within this area of the Irish Sea currently cover a number of habitat types, mostly granular in nature (sands and gravels). The benthic surveys generally indicated a relatively high diversity and species abundance indicative of a thriving benthic population in and around the proposed outfall pipeline route (marine section). For this to exist, the sediments are regularly replenished with organic

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material transported into the area by currents and suspended solids, which provide an important food source to both the infaunal and epifaunal communities. However, these animals have evolved over time to exist in a variety of habitats with different levels of organic enrichment and oxygen. Consequently, benthic communities, including those around the proposed outfall pipeline route (marine section), can tolerate large variations in organic enrichment, and subsequently oxygen levels, as conditions around them change. A typical community change as a result of organic enrichment, generally resulting from depleted oxygen levels from microbial respiration, is a notable increase in the number of small opportunistic species creating high species dominance. The reverse is generally true for low organic (subsequently high oxygen) communities where the number of species can be high but are represented by relatively few individuals. This latter group can help to regulate the conditions on the seabed through bioturbation, where the fauna reworks the substrates and creates burrows and tubes which maintain oxygenation of the lower sediments throughout the flow of oxygenated water into the interstitial spaces. The proposed outfall pipeline route (marine section) will create a plume of nutrient-enriched waters which will mostly disperse naturally on the prevailing tidal currents over a large area. The siting of the outfall has been undertaken based on modelling of the oceanography to maximise the dilutions and spread of this material so that localised enrichment will not occur. However, as the levels of DIN will increase slightly within close proximity of the marine diffuser, there is a possibility of increased organic enrichment to the seabed through increased primary productivity and organic flux to the seabed via the food chain, particularly during the summer months, when sea temperature and light conditions are suitable for photosynthesis. A summary of the different increases in DIN modelled are given in Chapter 8 Marine Water Quality in Volume 3 Part A of this EIAR. Results show that the dissipation of DIN over the area will not create eutrophication and associated decrease in oxygen levels in the sediments around the proposed outfall pipeline route (marine section). A similar example is demonstrated from a benthic monitoring programme in Massachusetts Bay conducted by the Massachusetts Water Resource Authority. This was to investigate soft-bottom sediment and macroinvertebrate conditions surrounding a similar secondarily treated wastewater outfall located 15 kilometres offshore (Nestler et al. 2013). The study was based on long-term monitoring over a 20-year period (between 1992 and 2012) and a relocation of an outfall in the year 2000, following concerns about potential effects of the discharge on the offshore benthic environment. These concerns focused on three issues: (1) eutrophication and related low levels of dissolved oxygen; (2) accumulation of toxic contaminants in depositional areas; and (3) smothering of animals by particulate matter. The study included surveys of sediments and soft-bottom communities at 14 near-field and far-field stations using traditional grab sampling, as well as sediment profile imaging and other camera techniques. Sediment conditions were characterised based on spore counts of the anaerobic bacterium, Clostridium perfringens, along with analyses of the macroinvertebrate community, sediment grain size composition and TOC. Results from the latest survey were consistent with previous monitoring results at this site and showed that the latest concentration of C. perfringens were highest at sites closest to the discharge, indicative of some solids from the treated wastewater at sites in close proximity (within 2km) to the outfall, but no variation was recorded within sediment grain size or TOC analysis (Diagram 9.8). An assessment of the macrofauna similarly indicated that there were no statistical impacts attributable to the outfall (Diagram 9.8), with some minor fluctuations recorded between years, reflecting regional population changes over time. The sediment profile imaging survey found no detrimental impact from the wastewater discharge resulting in low levels of dissolved oxygen in near-field sediments. The average thickness of the oxygenated sediment layer was greater in 2012 than previously reported during the baseline period.

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Where Tran = Transition area; NF = near-field and FF = far-field.

Diagram 9.8: (A) Mean Concentrations of Total Organic Carbon and (B) Infaunal Abundance in Four Areas of Massachusetts Bay (1992 to 2012)

Impact The modelling of the discharge shows that the discharge from the proposed marine diffuser will disperse and dissipate over a large area. This is predicted to have negligible long-term impacts to the marine benthos with possible minor changes recorded within the immediate vicinity of the proposed marine diffuser. The ecological value of the benthos is negligible, and therefore the significance of impact on the benthos in this area is likely to be Negligible. At a distance of >750m from the proposed marine diffuser location, the reef features within the Ireland’s Eye SAC are not predicted to be impacted by the dispersed discharge. Therefore, the significance of the impact is predicted to be none or Negligible. Plankton Although the level of DIN may imperceptibly increase regionally over a larger area, the impact to primary productivity and possible eutrophication to the surrounding sediments is expected to be negligible owing to the dispersion predicted by the hydrodynamic model. Where minor increases in DIN are recorded, this is likely to have a minor increase in phytoplankton productivity during the summer months. This may have a further enhancement to both the zooplankton populations and other biota further up the food chain (e.g. fish, suspension feeders, birds and marine mammals) where recorded.

Impact The modelling of the discharge shows that the discharge from the proposed marine diffuser will disperse and dissipate over a large area. Any increase in the levels of nutrients that does occur within the water column in the surrounding waters of the proposed marine diffuser is likely to have a negligible increase in phytoplankton activity (during the summer months) and, consequently, impact on some dependent groups further up the food chain. However, this is predicted to be of negligible magnitude and Negligible significance. Marine Mammals As for the predicted impact relating to habitat loss, secondary treated wastewater is predicted to have a maximum suspended sediment load of 35mg/l (95th percentile) over a naturally variable annual background of up to 45mg/l. As noted above, this is currently within the range routinely recorded for suspended sediments in this region and would be expected to disperse with the ambient seawater by a factor of 20 within 50m on discharge. Whilst this discharge is expected to provide a localised plume visible to marine mammals, particularly visual hunters such as pinnipeds, the presence of the plume is not expected to have a direct effect on the presence of cetaceans (such as bottlenose dolphins and harbour porpoises), as these species are routinely found in high turbidity shallow

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waters. However, as active hunters, these species may be attracted towards the proposed marine diffuser in search of prey species that themselves might be attracted to the physical structure of the outfall diffuser, the discharge itself or the increased productivity that may be found surrounding it.

Impact Owing to possible enhancement of fish life around the proposed marine diffuser location (attracted by the seabed structure and/or possible increased productivity), the impact is likely to be slightly beneficial to the marine mammals, particularly the seals, with a long-term duration (the lifetime of the proposed outfall pipeline route (marine section)) but generally negligible magnitude. This would result in a Negligible Beneficial impact for pinnipeds, but a Minor Beneficial impact to harbour porpoises in magnitude. However, as this area represents only a very small proportion of their foraging range, this significance of this impact is expected to be Negligible. Marine Fish and Shellfish The output from the hydrodynamic model indicates that the nutrient enriched plume will not affect inshore water quality as it disperses offshore. A 20-fold dilution will occur within 50m of the proposed marine diffuser. No negative impact on fish or shellfish species is expected at the site, or within the surrounding environment. The potential impacts on water quality, primarily as a result of elevated DIN levels, may impact on primary productivity in the immediate vicinity of the proposed marine diffuser, which in turn will pass up the food chain through increased zooplankton, although water quality is expected to increase in the area overall as a result of the Proposed Project. Effluent based nutrient enrichment may stimulate excessive algal growth locally, which has the potential to affect trophic interactions in the immediate vicinity of the proposed outfall pipeline route (marine section) (including the proposed marine diffuser) (Owili 2003). Through altering the food availability for various organisms, this may in turn impact localised commercial fish and shellfish populations positively or negatively. Other potential impacts may include bioaccumulation of in/organic compounds and depletion of oxygen in the immediate locale of the plume (Owili 2003). The findings of the hydrodynamic model indicate that the nutrient enrichment levels anticipated, and the modelled rate of dispersion offshore, are likely to have a negligible impact both locally and regionally upon fish and shellfish populations.

Impact The potential to increase a food source as well as the existence of a seabed structure over a long-term duration (the lifecycle of the Proposed Project), may increase fish densities in the area, although the level of this impact is expected to be of negligible magnitude for both fish (including migratory fish) and shellfish. The significance of this impact is expected, therefore, to be Negligible but beneficial throughout. A summary of the operational impacts is shown in Table 9.25 .

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Table 9.25: Summary of Impacts During the Operational Phase on Marine Ecology

Activity Impact Receptor Ecological Value Magnitude Duration Significance

Minor (Negligible Harbour due to proportion of Very high Negligible Long-term porpoise range and impact Loss of habitat type) Reef Very high None Long-term None or Negligible

Benthos Negligible Negligible Long-term Negligible

Reef Very high None Long-term None or Negligible

Plankton Negligible Negligible Long-term Negligible Negligible Minor Beneficial Harbour (potentially (Negligible due to Operation porpoise and Very high to beneficial due to Long-term proportion of bottlenose medium increased range) to Negligible dolphins Water quality productivity) Beneficial Negligible (potentially Negligible Pinnipeds Medium beneficial due to Long-term Beneficial increased productivity) Fish (including Negligible Low to medium Negligible Long-term salmonids) Beneficial Low (shellfish Negligible Shellfish Negligible Long-term waters nearby) Beneficial

9.6 ‘Do Nothing’ Impact The impact to the current ecological status based on a ‘do nothing’ scenario is likely to be Negligible, with a potential for increased pressures from deteriorating water quality conditions in certain locations during certain times of the year or during peak events (such as storms). However, overall, no significant change is expected within the current marine ecology environment.

9.7 Mitigation Measures

9.7.1 Construction Phase The use of trenchless construction methods beneath the Baldoyle Estuary SAC will minimise the impact to the marine ecology in the sensitive inshore areas during construction, although there is a minor risk of an air or bentonite breakout. On completion of the tunnel, the remainder of the planned surface construction is based on dredging in the offshore location. Additional mitigation will be required to minimise the impacts of noise and suspended sediments in order to prevent negative interaction with sensitive receptors in the area (in particular the cetaceans and the pinnipeds). A summary of mitigation for the marine ecology is summarised in Table 9.26. This mitigation is also included in the Outline CEMP, which will form part of the contract documents. Irish Water will be responsible for ensuring all mitigation measures are implemented and complied with by the contractor(s).

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Table 9.26: Summary of Proposed Mitigation Requirements for Marine Ecology

Activity Area at Risk Sensitive Receptor Mitigation Required Construction Phase Microtunnelling Leakage of pollutants and Feeding birds, benthos and juvenile No discharges to estuary under any Beneath Baldoyle suspended sediment loads fish circumstances. Estuary from compound into estuary Managed operations with bunded storage areas and sediment settlement areas. CEMP including Surface Water Management Plan. Air breakout to surface Management of pressures No surface mitigation required Bentonite breakout Managed volumes and pressures of bentonite used. Noise and vibration All marine ecology No mitigation required. Dredging for the Habitat loss Benthos area of 0.04km2 by removal No mitigation required. proposed outfall and 0.12km2 by smothering pipeline route Suspended sediments Impact to Annex I Reef within SAC Dredging discharges from the hopper will (marine section) be restricted to flooding tides only. Monitoring of plume during dredging operations (see text below table). Other marine ecology No mitigation required. Noise and vibration if option Marine mammals Detailed mitigation plan (see text below for piling in a caisson for table) required and seasonal connection with dredging considerations. required Passive acoustic monitoring and marine mammal observers (MMOs) to establish safe zone. Noise and vibration of Marine mammals Minimise duration of dredging operations. dredging Monitoring of acoustic output levels and carrying out marine mammal observations. Fish No mitigation required. Pollution All marine ecology Implementation of CEMP. This includes strict adherence to MARPOL guidelines, auditing of CEMP, bunded storage areas for fuels and control of compound drainage, etc. No discharge or disposal of waste to sea under any circumstances. Installation of Habitat disturbance Benthos No mitigation required. proposed marine Noise and vibration Marine mammals Minimise duration of dredging operations. diffuser Monitoring of acoustic output levels and carry out marine mammal observations. Operational Habitat loss Benthos on-site No mitigation required. Annex I Reef (Ireland’s Eye) No mitigation required. Pollution All marine ecology Output to be secondary treated with strict targets for suspended sediment and DIN level outputs (see Chapter 4 Description of the Proposed Project in Volume 2 Part A of this EIAR).

Monitoring of Plume During Dredging Operations

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The turbidity will be monitored using a buoy-mounted turbidity meter with telemetering back to the dredger to monitor potential impacts from dredging activity. As the reef is only prone to sedimentation during slack water periods, a slightly elevated level of Total Suspended Solids (TSS) up to 40mg/l (the natural standard deviation for the year) above a daily background will be permitted off the northern coastline of Ireland’s Eye. If this level increases above this threshold as a result of dredging activity, then the discharge of material will be temporarily halted to allow the resulting plume to disperse. This is particularly important 30 minutes before and after slack water where increased suspended sediments can settle within the SAC. Microtunnelling – Bentonite Breakout The control and management of pressures during the microtunnelling processes will be undertaken to prevent air and bentonite breakouts. However, in the unlikely event of a bentonite breakout occurring, which results in a saltmarsh area high up on the foreshore being covered, intervention will be required. Intervention will involve washing the vegetation using a seawater pump and spray. Typically, this would be carried out during a high water period where washings can disperse out of the estuary naturally. Sites will only be accessed by foot (without the use of plant). Should bentonite breakout in a saltmarsh area lower down on the shoreline in areas routinely covered by seawater, this will be left to disperse naturally over the tidal cycle. All bentonite usage will be monitored through materials balance calculations, pressure monitoring in the lines and above ground visual assessment of the works to ensure that, should a breakout occur, the volume is minimised. In the event of a bentonite breakout, the site will be monitored for chemistry and macroinvertebrate communities to ensure no residual impacts. This may include both benthic and water quality measurements. Increased Suspended Solids Disturbance of intertidal and subtidal habitats will be minimised so as to reduce the creation of suspended solids within the marine and estuarine habitats. The tunnelling compound spanning either side of the Baldoyle Estuary will be subject to surface water management as part of the CEMP to prevent all runoff into the watercourses and the estuary. The potential for an accidental release of bentonite will be minimised by closely monitoring its use during all works. Dredging works in the shallow areas will be carried out using a backhoe dredger with the spoil side cast at the seabed to minimise the lifting of the bucket through the water column. This will reduce losses of suspended sediments from this material and preserve the sediment composition as much as possible at bed level. Dredging carried out close to the Ireland’s Eye SAC will be carried out on neap tides where possible. Monitoring of turbidity will be carried out during peak dredging activity, and operations will be restricted to flooding tides if a plume is detected >50mg/l TSS above background on the northern coastline of Ireland’s Eye. Noise and Vibration Pollution Noise and vibration from the microtunnelling and dredging operations during the construction of the proposed outfall pipeline route (marine section) (including the proposed marine diffuser) will be minimised by selecting the most appropriate equipment, dependent upon ground conditions and noise signatures. The specifications of piling systems for caisson deployments for the construction of the proposed marine diffuser, the interface connection with the microtunnelling or the fibre optic cable crossing will be assessed for likely noise outputs to assess noise impacts when working within the Rockabill to Dalkey Island SAC. Mitigation will be undertaken during piling and dredging works to ensure the are no noise impacts to marine mammals (including harbour porpoises) near the works. This will include MMOs using a high frequency hydrophone system to establish an operational safe zone around the site. This will prevent the commencement of

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operations in the event that sensitive receptors (pinnipeds and cetaceans) are observed within this perimeter. The following mitigation measures will also be implemented:

• Following appropriate guidelines from the regulatory authorities, the NPWS (2014), the following measures are proposed to remove the risk of direct injury to marine mammals in the area of operations: A trained and experienced MMO will be put in place during piling, dredging and pipeline laying. The MMO will scan the surrounding area to ensure no marine mammals are in a pre-determined exclusion zone in the 30-minute period prior to operations. It is proposed that this exclusion zone is 500m for dredging activities and 1,000m for piling activities. No works will take place should mammals be recorded in the exclusion zone. • Noise-producing activities will only commence in daylight hours where effective visual monitoring, as performed and determined by the MMO, has been achieved. Where effective visual monitoring is not possible, the sound-producing activities will be postponed until effective visual monitoring is possible. Visual mitigation for marine mammals (in particular harbour porpoise) will only be effective during daylight hours and if the sea state is 2-3 or less (Beaufort scale) or less. • For piling activities, where the output peak sound pressure level (in water) exceeds 170dB, a ramp-up procedure must be employed following the pre-start monitoring. Underwater acoustic energy output will commence from a lower energy start-up and thereafter be allowed to gradually build up to the necessary maximum output over a period of 20 to 40 minutes.

o Once operations have begun, operations will cease temporarily if a cetacean or seal is observed swimming in the immediate (<50m) area of piling and dredging and work can be resumed once the animal(s) have moved away. o Any approach by marine mammals into the immediate (<50m) works area should be reported to the NPWS. o If there is a break in piling activity for a period greater than 30 minutes, then all pre-activity monitoring measures and ramp-up will recommence as for start-up. • Once normal operations commence (including appropriate ramp-up procedures), there is no requirement to halt or discontinue the activity at night-time, nor if weather or visibility conditions deteriorate, nor if marine mammals occur within a radial distance of the sound source that is 500m for dredging works, and 1,000m for piling activities. • The MMO will keep a record of the monitoring using ‘MMO form location and effort (coastal works)’ available from the NPWS and submit to the NPWS on completion of the works, as described in the NPWS guidance (2014). • In order to reliably quantify the zone of responsiveness associated with the proposed programme of piling activities associated with the interface pit or cable crossing, a vessel-deployed hydrophone will be used to confirm the sound source level of the operation. Additionally, passive acoustic monitoring will be used to provide additional support to the identification of harbour porpoises or other cetaceans within the survey area. The effective range of the passive acoustic monitoring system will be dictated by the frequency, with the ultra-high frequency used by porpoises likely to be limited to within 500m of the passive acoustic monitoring system. Pollutants and Waste A detailed CEMP will be established prior to construction (see Outline CEMP). This will follow best practice for the storage, handling and disposal of hazardous/non-hazardous materials to prevent chemical pollution. All fuels or chemicals kept on the construction site will be stored in protected containers, and all refuelling and maintenance will be carried out in bunded containment areas. Refuelling and maintenance in areas draining directly to water habitats will be avoided where possible. Oil interceptors will also be installed in appropriate locations. Equipment will be regularly maintained and leaks repaired immediately. Accidental spillages will be contained and cleaned up

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immediately. Remediation measures will be carried out in the unlikely event of pollution of the marine environment.

9.7.2 Operational Phase The Sustainable Drainage Systems in place at the proposed WwTP and Abbotstown pumping station will need to be maintained to ensure proper functioning during the operation of the Proposed Project.

9.8 Residual Impacts A summary of the residual impacts where non-negligible impacts were identified and where options for mitigation can be applied are outlined in Table 9.27.

Table 9.27: Summary of Residual Impacts following Proposed Mitigation Measures on the Marine Ecology

Ecological Significance (Pre- Mitigation Residual Activity Impact Receptor Value Mitigation) Description Significance

Negligible to Air breakout Saltmarsh habitat Very high Minor Tunnelling beneath Pressure Minor Baldoyle Estuary Bentonite management Saltmarsh habitat Very high Minor Negligible breakout None expected Migratory fish and Medium Minor due to very Negligible pinnipeds limited exposure Turbidity monitoring and Suspended control of timings sediment plume Reef habitat (SAC) Very high Minor to Moderate Negligible Dredging of outfall during peak periods if plume effects detected Harbour porpoise No mitigation Very high Minor Minor (SAC) possible Noise and Very high Restricting Harbour porpoise Minor Negligible vibration (SAC) operations around marine Pinnipeds Medium Minor Negligible mammal observations and passive acoustic Tunnel interface Harbour porpoise monitoring. Noise and using piling and/or and bottlenose High Minor Negligible vibration caisson installation dolphins Possible seasonal restrictions No mitigation Migratory fish Medium Minor Minor possible Restricting operations around marine mammal Installation of observations and Noise and Very high proposed marine Harbour porpoise Minor passive acoustic Negligible vibration (SAC) diffuser monitoring.

Possible seasonal restrictions

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Envir onmental Impact Assessment Report: Vol ume 3 Part A of 6 Irish Water

Environmental Impact Assessment Report: Volume 3 Part A of 6

Contents 10. Biodiversity (Marine Ornithology) ...... 1 10.1 Introduction ...... 1 10.2 Methodology ...... 3 10.2.1 Introduction ...... 3 10.2.2 Estuarine Ornithological Survey ...... 3 10.2.3 Coastal and Marine Vantage Point Surveys ...... 4 10.2.4 Boat Based Assessment of Auk Fledging ...... 4 10.2.5 Defining Ecological Importance ...... 4 10.2.6 Defining Ecological Impacts ...... 5 10.2.7 Determination of Significance ...... 6 10.2.8 Non-Statutory Consultation ...... 7 10.3 Baseline Environment ...... 8 10.3.1 Wintering Birds and the Baldoyle Bay Special Protection Area ...... 8 10.3.2 Adjacent Special Protection Areas and Designated Sites ...... 9 10.3.3 Estuarine Ornithological Baseline ...... 9 10.3.4 Marine Birds and Related Special Protection Areas in the Vicinity of Dublin Bay ...... 21 10.3.5 Marine Birds Ornithological Baseline ...... 22 10.3.6 Ecological Value of Estuarine and Marine Birds ...... 29 10.4 Parameters for Assessment ...... 31 10.4.1 Overview of the Proposed Project Works and Magnitude of Potential Impacts ...... 31 10.4.2 Parameters Included in Assessment (Construction Phase) ...... 31 10.4.3 Parameters Excluded from Assessment (Construction Phase) ...... 33 10.4.4 Parameters Included in Assessment (Operational Phase) ...... 34 10.4.5 Parameters Excluded from Assessment (Operational Phase) ...... 35 10.5 Potential Impacts on Ornithological Receptors ...... 35 10.5.1 Disturbance and/or Displacement ...... 35 10.5.2 Indirect Impacts ...... 37 10.6 Assessment of Significance ...... 37 10.6.1 Construction Phase ...... 37 10.6.2 Operational Phase ...... 49 10.7 ‘Do Nothing’ Impact ...... 49 10.8 Cumulative Impacts ...... 49 10.9 Mitigation Measures ...... 49 10.9.1 Construction Phase – Estuarine Ornithology ...... 49 10.9.2 Construction Phase – Marine Ornithology ...... 50

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10.9.3 Operational Phase – Estuarine Ornithology ...... 51 10.9.4 Operational Phase – Marine Ornithology ...... 52 10.10 Residual Impacts ...... 52 10.10.1 Estuarine Ornithology ...... 52 10.10.2 Marine Ornithology ...... 52 10.11 References ...... 52

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10. Biodiversity (Marine Ornithology)

This Chapter of the Environmental Impact Assessment Report identifies, describes and assesses the likely significant effects of the proposed Greater Dublin Drainage Project (hereafter referred to as the Proposed Project) on estuarine, coastal and marine ornithology. The key areas of the route which may be particularly sensitive are the Baldoyle Bay and Ireland’s Eye Special Protection Areas and the bird species associated with them. Birds are highly mobile, so they can occur both inside and outside designated areas with which they are associated.

Estuarine and marine surveys were undertaken between 2014 and 2017 to assess the bird populations using the areas in which the proposed outfall pipeline route (marine section) will be constructed and their surroundings. Monitoring of the Ireland’s Eye auk colony in summer 2016 and 2017 was also carried out.

During the Construction Phase, proposed temporary construction compounds for microtunnelling works will be established adjacent to the eastern and western boundaries of Baldoyle Bay. Providing that the embedded mitigation of suitable screening at each of the proposed temporary construction compounds is in place prior to construction, no impacts due to disturbance are predicted.

The temporary piling noise during the Construction Phase at the microtunnelled/subsea interface, and the fibre optic cable crossing, could result in disturbance to foraging seabirds. The construction of the proposed outfall pipeline route (marine section) subsea section, including the proposed marine diffuser, has the potential to result in disturbance to seabirds from Ireland’s Eye, with auks being particularly sensitive. Auk chicks leaving Ireland’s Eye at the end of the breeding season may be flightless and, though unlikely, in some instances could approach the proposed construction corridor in large numbers. Such birds are highly susceptible to disturbance.

In order to ensure that the Ireland’s Eye Special Protection Area and the seabirds it supports, particularly auks, are not disturbed during the Construction Phase, and to ensure that the Special Protection Area is not disturbed unnecessarily, a Vessel Management Plan for marine ornithology will be implemented.

No impacts are predicted as a result of the Operational Phase of the Proposed Project.

There are also no predicted significant residual effects upon estuarine, coastal and marine ornithological receptors.

10.1 Introduction This Chapter of the Environmental Impact Assessment Report (EIAR) provides a characterisation of the receiving environment and an assessment of the ecological impacts of the Greater Dublin Drainage Project (hereafter referred to as the Proposed Project) on estuarine, coastal and marine ornithology. The assessment addresses the potential impacts on birds using the estuarine, intertidal and marine environments. Please refer to Chapter 11 Biodiversity (Terrestrial and Freshwater Aquatic) in Volume 3 Part A of this EIAR for the impact assessment on terrestrial ornithology including breeding birds. The table below includes a summary of the Proposed Project elements. A full description of the Proposed Project is detailed within Volume 2 Part A, Chapter 4 Description of the Proposed Project, of this EIAR.

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Proposed Project Outline Description of Proposed Project Element Element

Proposed  WwTP to be located on a 29.8 hectare (ha) site in the townland of Clonshagh (Clonshaugh) in Fingal.  500,000 population equivalent wastewater treatment capacity. Wastewater  Maximum building height of 18m. Treatment Plant  Sludge Hub Centre (SHC) to be co-located on the same site as the WwTP with a sludge handling and (WwTP) treatment capacity of 18,500 tonnes of dry solids per annum.  SHC will provide sustainable treatment of municipal wastewater sludge and domestic septic tank sludges generated in Fingal to produce a biosolid end-product.  Biogas produced during the sludge treatment process will be utilised as an energy source.  Access road from the R139 Road, approximately 400m to the southern boundary of the site.  Egress road, approximately 230m from the western boundary of the site, to Clonshaugh Road.  A proposed temporary construction compound to be located within the site boundary. Proposed  Abbotstown pumping station to be located on a 0.4ha site in the grounds of the National Sports Campus at Abbotstown. Abbotstown pumping  Abbotstown pumping station will consist of a single 2-storey building with a ground level floor area of 305m2 station and maximum height of 10m and a below ground basement 17m in depth with floor area of 524m2 incorporating the wet/dry wells.  The plan area of the above ground structure will be 305m2 and this will have a maximum height of 10m.  A proposed temporary construction compound to be located adjacent to the Abbotstown pumping station site. Proposed orbital  The orbital sewer route will intercept an existing sewer at Blanchardstown and will divert it from this point to the WwTP at Clonshagh. sewer route  Constructed within the boundary of a temporary construction corridor.  13.7km in length; 5.2km of a 1.4m diameter rising main and 8.5km of a 1.8m diameter gravity sewer.  Manholes/service shafts/vents along the route.  Odour Control Unit at the rising main/gravity sewer interface.  Proposed temporary construction compounds at Abbotstown, Cappoge, east of Silloge, Dardistown and west of Collinstown Cross to be located within the proposed construction corridor. Proposed North  The NFS will be intercepted in the vicinity of the junction of the access road to the WwTP with the R139 Road in lands within the administrative area of Dublin City Council. Fringe Sewer (NFS)  NFS diversion sewer will divert flows in the NFS upstream of the point of interception to the WwTP. diversion sewer  600m in length and 1.5m in diameter.  Operate as a gravity sewer between the point of interception and the WwTP site. Proposed outfall  Outfall pipeline route (land based section) will commence from the northern boundary of the WwTP and will run to the R106 Coast Road. pipeline route (land  5.4km in length and 1.8m in diameter. based section)  Pressurised gravity sewer.  Manholes/service shafts/vents along the route.  Proposed temporary construction compounds (east of R107 Malahide Road and east of Saintdoolaghs) located within the proposed construction corridor. Proposed outfall  Outfall pipeline route (marine section) will commence at the R106 Coast Road and will terminate at a discharge location approximately 1km north-east of Ireland’s Eye. pipeline route  5.9km in length and 2m in diameter. (marine section)  Pressurised gravity tunnel/subsea (dredged) pipeline.  Multiport marine diffuser to be located on the final section.  Proposed temporary construction compounds (west and east of Baldoyle Bay) to be located within the proposed construction corridor. Proposed Regional  Located on an 11ha site at Newtown, Dublin 11.  Maximum building height of 15m. Biosolids Storage  Further details and full impact assessment are provided in Volume 4 Part A of this EIAR. Facility

The total Construction Phase will be approximately 48 months, including a 12 month commissioning period to the final Operational Phase. The Proposed Project will serve the projected wastewater treatment requirements of existing and future drainage catchments in the north and north-west of the Dublin agglomeration, up to the Proposed Project’s 2050 design horizon. Please also note that the ornithological impact assessment of the proposed Regional Biosolids Storage Facility aspect of the Proposed Project is addressed in Chapter 6 Biodiversity in Volume 4 Part A of this EIAR. There is no marine ornithological assessment of the proposed Regional Biosolids Storage Facility, as the site is located inland.

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10.2 Methodology

10.2.1 Introduction The marine ornithology assessment is based on the construction and operation of a new proposed outfall pipeline route (marine section). This will consist of a microtunnelled section commencing at the western side of the Baldoyle Bay Estuary, a subsea section which begins off the coast of Velvet Strand Beach and a proposed marine diffuser located approximately 1km north-east of the island of Ireland’s Eye (see Chapter 4 Description of the Proposed Project). The following sources of information have been used during the assessment:

 Literature assessment (using published data and literature) of the Fingal coastline, including Fingal Local Biodiversity Action Plan (LBAP) (Fingal County Council (FCC) 2010), and citations for Baldoyle Bay, Ireland’s Eye and Howth Head Coast Special Protection Areas (SPAs); and  Estuarine and coastal surveys, encompassing: o Walkover survey data collected between December 2014 and March 2018 to characterise the abundance and distribution of bird species associated with the Baldoyle Bay SPA and surrounding habitats; o Vantage Point (VP) surveys from two locations between December 2014 and March 2018 to assess the usage by bird species of the proposed outfall pipeline route (marine section); and o Boat based assessment of the timing of auk species leaving Ireland’s Eye in the later part of the breeding season. The methodology for the assessment of impacts on estuarine, coastal and marine ornithological interests is in line with Guidelines for Ecological Impact Assessment in Britain and Ireland Marine and Coastal issued by the Chartered Institute of Ecology and Environmental Management (CIEEM) for marine environments (CIEEM 2010) and Guidelines for Ecological Impact Assessment in the UK and Ireland Terrestrial, Freshwater and Coastal (CIEEM 2016) for terrestrial environments. The Environmental Protection Agency’s (2017) Draft Guidelines on the Information to be Contained in Environmental Impact Assessment Reports were also consulted.

10.2.2 Estuarine Ornithological Survey A wetland bird survey was undertaken during 2014/2015, 2015/2016 and 2017/18 to characterise the ornithological interests of Baldoyle Bay and surrounding areas, particularly with respect to spatial and temporal distribution of key SPA species. A summary of survey effort is provided in Table A10.1, Appendix A10.1 in Volume 3 Part B of this EIAR. Surveys were carried out twice per month between December 2014 and May 2016, and an up-to-date survey campaign was restarted in 2017 with surveys again being conducted twice per month between March 2017 and March 2018. The survey methodology was based on the British Trust for Ornithology (BTO) Wetland Bird Survey (WeBS) and Irish WeBS (I-WeBS) methodology as outlined in Gilbert et al. (1998) and BTO (2016a; 2016b). The survey method included both high tide and low tide waterbird counts. Surveys were conducted throughout a range of weather conditions and times of the day where good visibility prevailed. The spatial extent of the surveys is illustrated in Figure 10.1 Location and Extent of Marine, Coastal and Estuarine Ornithological Surveys. Full details of the methodologies employed during these surveys are provided in Appendix A10.1 in Volume 3 Part B of this EIAR.

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10.2.3 Coastal and Marine Vantage Point Surveys VP surveys were carried out from December 2014, with six hours of surveys carried out monthly per VP to July 2017. Surveys were carried out twice per month between December 2014 and July 2016, and again twice per month between March 2017 and March 2018. Details of survey effort are provided in Table A10.5 of Appendix A10.1. Two VPs were utilised: one on the mainland (“Velvet Strand” (IO250423, Lat. 53.41631, Long. -6.11966, mean viewing angle 70°)), and one on Ireland’s Eye (“Ireland’s Eye” (IO287415, Lat. 53.40792, Long. - 6.06387, mean viewing angle 0°). The Velvet Strand VP covered the area of the proposed outfall pipeline route (marine section) out to sea using a 2km viewing arc, and the Ireland’s Eye VP covered the remaining proposed outfall pipeline route (marine section) using a 2km viewing arc. In this way, the proposed outfall pipeline route (marine section) and a large buffer was covered by the surveys. The locations of these VPs and the viewing arcs are illustrated in Figure 10.1 Location and Extent of Marine, Coastal and Estuarine Ornithological Surveys. Surveys were timed to give coverage over a range of tidal states through the year, and to ensure that both spring and neap tides were covered. Key species/species groups for the VP surveys were primarily seabirds which utilise the marine environment for foraging and roosting/loafing and social interaction, particularly during the breeding season when nests are established on cliffs or offshore islands such as the Ireland’s Eye SPA. Full details of the methodologies employed during these surveys, along with a priority species list and detailed records of survey timings is provided in Appendix A10.1.

10.2.4 Boat Based Assessment of Auk Fledging There is a substantial population of breeding auks at Ireland’s Eye. When fledging, chicks and one or both parents tend to depart nests and disperse from breeding colonies to offshore areas to moult and avoid predation of chicks by other seabirds. This can result in a situation where many birds are in the water at once, which could be susceptible to disturbance and displacement. The aim of the surveys was to assess the use of waters surrounding Ireland’s Eye by auks during this leaving event.

Surveys were conducted in July 2016 and July 2017 and consisted of a single surveyor on a boat travelling around Ireland’s Eye and noting numbers of auk chicks in nests on the cliffs, and any birds in the water. Visits occurred approximately twice weekly and were supplemented by additional observations from the boatman, who was present in the area almost daily.

10.2.5 Defining Ecological Importance The importance of different ecological receptors was defined as negligible (site), low (local), medium (county), high (national) or very high (international). The criteria used to inform decisions regarding the value of each receptor are outlined in Table 10.1.

Table 10.1: Ecological Value Criteria

Ecological Value Criteria Used in this Chapter Very high Populations present within survey area exceed 1% threshold of international importance. (international) Cited interest feature of connected/relevant SPA or Ramsar. High Species that contribute to the integrity of an SPA but which are not cited as a species for which the site is (national) designated. Species listed on Annex I of Directive 2009/147/EC of 30 November 2009 of the European Parliament and of the Council on the conservation of wild birds (Birds Directive). Resident or regularly occurring populations (>1% national threshold) of the following: - Species protected under the Wildlife Acts (1976-2002); and - Species listed on the Red or Amber List of Birds of Conservation Concern in Ireland (BoCCI).

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Ecological Value Criteria Used in this Chapter Resident or regularly occurring populations of the above populations where a 1% national threshold is not available (excluding BoCCI Amber listed species). Medium Resident or regularly occurring populations (<1% national threshold) of the following: (county) - Species protected under the Wildlife Acts (1976-2002); and - Species listed on the Red List of BoCCI. For BoCCI Amber listed species, resident or regularly occurring populations of the above populations are >1% national threshold or a 1% national threshold is not available. Locally important populations of priority species identified in a Local Area Plan (LAP) (if one has been prepared). Populations of species that are uncommon within the county. Species that are rare or undergoing a decline in quality or extent at a national level. Low All other species of conservation interest, i.e. those species on the BoCCI Amber (<1% national threshold or (local) present in very low peak numbers) and Green lists Negligible All other features that are widespread and common and which are not present in locally, regionally or (site) nationally important numbers.

The aim of the EIAR is to report on significant impacts, rather than every conceivable impact. As such, following the assessment of baseline data, a number of receptors were scoped out of the assessment as the survey results indicated that significant impacts were not likely to occur, for example if the number of individuals recorded was extremely low in relation to their relevant reference populations and/or site usage was rare. Such impacts do not require assessment under the terms of the EIA legislation in Ireland. Both the Draft Guidelines on Information to be Contained in Environmental Impact Assessment Reports (Environmental Protection Agency 2017) and Guidelines for Ecological Impact Assessment in the UK and Ireland Terrestrial, Freshwater and Coastal (CIEEM 2016) recommend that only information that is required for the assessment of likely significant impacts is included.

10.2.6 Defining Ecological Impacts The impact assessment process involves identifying and characterising impacts and, where adverse impacts on ecological receptors cannot be avoided, incorporating measures to mitigate these impacts. The significance of any residual impacts after mitigation must also be assessed. If relevant, appropriate compensation measures to offset significant residual impacts, along with opportunities for ecological enhancement, should be identified.

When describing ecological impacts, the following parameters are considered:

 Physical nature;  Type (positive/negative, direct/indirect);  Spatial extent;  Magnitude (Table 10.2);  Duration (Table 10.3);  Timing;  Frequency; and  Reversibility. Definitions of all of these parameters are provided in CIEEM (2016).

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Table 10.2: Criteria for Determining the Magnitude of Potential Ecological Impacts

Magnitude Examples Very high The proposal (either on its own or with other proposals) will result in a total loss or very major alteration to key elements of the baseline conditions such that character/composition/attributes will be fundamentally changed and may be lost from the site altogether. High The proposal (either on its own or with other proposals) will result in a major alteration to key elements/features of the baseline conditions such that character/composition/attributes will be fundamentally changed. Medium The proposal (either on its own or with other proposals) will result in a loss or alteration to one or more key elements/features of the baseline conditions such that character/composition/attributes of baseline would be partially changed. Low The proposal (either on its own or with other proposals) will result in a minor shift away from baseline conditions. Change arising from the loss/alteration will be discernible, but underlying character/composition/attributes of conditions would be similar to pre-development circumstances/patterns. Negligible The proposal (either on its own or with other proposals) will result in a very slight change from baseline conditions (barely distinguishable from or approximating to the ‘no change’ situation).

Table 10.3: Duration of Impact

Duration Criteria Permanent Effects continuing indefinitely beyond one human generation (approximately 25 years), except where there is likely to be a substantial improvement after this period, whereby these would be described as ‘very long-term effects’. Temporary Long-term (15 to 25 years or longer) Medium (5 to 15 years) Short-term (up to 5 years)

10.2.7 Determination of Significance The overall significance of an ecological impact on a particular receptor is a function of the impact magnitude and ecological value. As a starting point, this is determined by using the matrix presented in

Table 10.4. However, the results from the impact matrix are not considered to be definitive. The final significance of an impact is determined through a combination of the impact matrix, a review of available evidence (where possible with reference to published scientific studies relevant to the impact and receptor under assessment) and application of expert judgement to ensure that the conclusion is consistent with the available evidence. The assessment takes account of design measures included to avoid unnecessary impacts.

Once identified and characterised for magnitude and significance, each potential impact is assigned a confidence of prediction (post-mitigation). CIEEM (2010) outlines the following terminology for outlining the likelihood of impact occurrence:

 Certain (100%);  Near-certain (95–100%);  Probable (50–95%);  Unlikely (5–50%); and  Extremely unlikely (0–5%). A statement of residual impacts (taking account of embedded mitigation) is then provided. Residual impacts identified as ‘Moderate’ and/or ‘Major Adverse’ are considered to be ecologically significant. Impacts of ‘Negligible’ or ‘Minor’ significance are considered to be not significant.

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Table 10.4: Impact Significance Matrix

Ecological Value Impact Significance Very High High Medium Low Negligible

Very High Major Major Major Moderate Minor

High Major Major Moderate Minor Negligible Medium Major Moderate Minor Minor Negligible

Low Moderate Minor Minor Negligible Negligible Magnitude Negligible Minor Negligible Negligible Negligible Negligible

10.2.8 Non-Statutory Consultation The following table summarises the issues raised during non-statutory consultation on the Proposed Project.

Table 10.5: Issues Raised During Non-Statutory Consultation on the Proposed Project.

Stakeholder Date Submission Details Received

An Taisce 17 January  Concerns raised about the potential impact on protected areas: Baldoyle Bay 2014 candidate Special Area of Conservation (cSAC) (Site Code: 000199), Baldoyle Bay SPA (Site Code: 004016) and the Rockabill to Dalkey Island cSAC (Site Code: 003000).  Environmental Impact Statement should address potential impacts on each protected area and relevant mitigation measures.

BirdWatch Ireland 12  Concerns regarding activities near Baldoyle Bay SPA (Site Code: 004016). December  Concerns regarding the proximity of the proposed outfall pipeline route (marine 2013 section) to Ireland’s Eye SPA (Site Code: 004117).  Potential impact of nutrient reduction on the estuarine environment.  Issues with disturbance relating to breeding seabirds and wintering waterbirds.  Location of the proposed WwTP (site boundary proposed at 50m from Cuckoo Stream, a tributary of the Mayne River – struggling with ecological status).

Department of Culture, 10 January  Mitigation measures for proposed drilling under Baldoyle Bay cSAC to include Heritage and the 2014 avoidance of the wintering bird season, if construction is likely to disturb wintering Gaeltacht National Parks birds. and Wildlife Service  Portmarnock South LAP (FCC 2013) contains bird data which may be of use to the (Formerly Department of proposed tunnelling within the area covered by the LAP. Arts, Heritage and the  Proposed Project should be subject to Appropriate Assessment Screening and, where Gaeltacht) necessary, Appropriate Assessment as per Article 6.3 of Council Directive 92/43/EEC on the conservation of natural habitats and of wild fauna and flora (Habitats Directive).  Consultation with the relevant Local Authorities is recommended to determine if there are any projects or plans which alone or in combination could impact on any Natura 2000 sites.

BirdWatch Ireland 08  The construction of the proposed pipeline routes and potential impacts to December conservation interests in the SPAs and SACs on the route of the pipeline and out into 2017 the Irish Sea. BirdWatch Ireland’s I-WeBS data and other survey data for bird species relevant to these sites and other sites not designated but important for birds will need to be consulted and included in the assessment of impacts.  Migratory bird species may use fields en route from the proposed WwTP to the coast for foraging. This may include light-bellied brent geese, oystercatchers, curlew and more. It would be worthwhile contacting the Irish Brent Goose Study Group about any data that they might have for brent geese in this area.  The assessment of cumulative impacts of the Proposed Project in combination with other potential projects, as well as other projects which have inputs to the waters of

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Stakeholder Date Submission Details Received Dublin Bay, will require careful consideration. This includes projects which currently permit dumping at sea of dredge materials and other marine pollutants.  The waters surrounding the pipeline outfall pipeline route (marine section) are important feeding grounds for several conservation interests such as kittiwake, which has been listed as Vulnerable on the EU Red List of birds, and Annex 1 bird species such as common tern and roseate tern amongst others. Assessment of impacts on these species will be important.  Assessment of the impacts on forage fish for bird species should also be included.  The impacts on water quality and a description of contingency plans for pollution incidents will need to be carefully considered. The potential failures to the treatment process as well as failures at the proposed outfall pipeline route (marine section) discharge point will need to be described and mitigation developed.  The timing of any construction works which may impact on conservation interests of the SPAs both inside and outside of the sites must avoid sensitive times for species (e.g. winter months for overwintering species).  The data that BirdWatch Ireland has on bird species in the area of the Proposed Project may throw up other issues which will need to be considered.  The precautionary principle should also apply.

10.3 Baseline Environment The proposed outfall pipeline route (marine section) extends under or across habitats used by birds using Baldoyle Bay and the nearshore and marine environments between Velvet Strand and Ireland’s Eye.

10.3.1 Wintering Birds and the Baldoyle Bay Special Protection Area Baldoyle Bay is a sheltered estuary separated from the Irish Sea by the Portmarnock sand dune system (Figure 10.1 Location and Extent of Marine, Coastal and Estuarine Ornithological Surveys). Two small rivers, the Mayne River and the Sluice River, flow into the Baldoyle Bay. At low tide, extensive areas of intertidal mixed substrate flats are exposed. Areas of saltmarsh occur near Portmarnock Bridge and at Portmarnock Point, with narrow strips found along other parts of Baldoyle Estuary.

Baldoyle Bay is designated as an SPA under the Birds Directive. It is also designated as a Ramsar site and an Important Bird Area. It regularly supports an internationally important population of wintering light-bellied brent goose, and nationally important populations of ringed plover, bar-tailed godwit, shelduck, golden plover and grey plover. These species are listed as Special Conservation Interests (SCIs), along with the wetland habitats within the SPA boundary.

Nationally important populations of great-crested grebe and pintail are also present. Other species which occur in considerable numbers during the wintering season are teal, mallard, common scoter, oystercatcher, lapwing, knot, dunlin, black-tailed godwit, curlew, redshank, greenshank and turnstone. These species are also included in the SPA citation.

Table 10.6 summarises the Baldoyle Bay SPA qualifying species. Five-year population means for each species are also provided: one set from when the site was designated, and more-recent equivalents.

Conservation objectives provided for the site (National Parks and Wildlife Service 2013) are considered in more detail in the Natura Impact Statement.

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10.3.2 Adjacent Special Protection Areas and Designated Sites Baldoyle Bay is one of several neighbouring wetland sites of significant importance for overwintering waterbirds in the wider Dublin Bay and Fingal area. Other sites include:

 Malahide Estuary SPA (004025), 6km north of Baldoyle Bay;  Rogerstown Estuary SPA (004015), 11km north;  Skerries Island SPA (004122), 19km north;  North Bull Island SPA (004006), 3km south; and  South Dublin Bay and Tolka River Estuary SPA (004024), 9km south. Together, these sites regularly support more than 50,000 wintering waterbirds and are an area of international importance (Tierney et al. 2017). Waterbirds are likely to undertake regular movements around Dublin Bay and neighbouring SPAs during the wintering season.

To the west of Baldoyle Bay are the ‘Portmarnock South Zoned Lands’ which form part of the Portmarnock South LAP. The Portmarnock South LAP seeks to protect and enhance the function of the ecological buffer zone through appropriate mitigation and management measures as set out in the Green Infrastructure and Landscape Strategy. This is reflected in Table 5.0 of Section 5 of that LAP where it proposes that a ‘quiet zone’ is ‘established to the south of the residential development area to cater for Brent Geese and wader species. The ‘quiet zone’ to consist of grassland pasture. This ‘quiet zone’ will be enclosed by a fence and hedge to prevent disturbance during the winter migratory bird season. The enclosure must be dog proof but can permit overlooking of the ‘quiet zone’ e.g. 1.2 metre high fence with hedge planting of native species’.

The Portmarnock South Zoned Lands include a low intervention landscape approach to the ecological buffer zone lands to retain the supporting ecological functions that this landscape provides to the estuary habitats, including a ‘quiet zone’ for migratory birds and arable crop areas for native bird species.

10.3.3 Estuarine Ornithological Baseline Sources of Information

Appendix A10.1 presents the peak monthly counts and the mean of these counts (peak mean) of the estuarine walkover surveys. Table A10.2 of Appendix A10.1 contains peak mean data for the Baldoyle Bay SPA SCIs and Table A10.3 contains data for the other named qualifying features. Two-year peak means recorded during the estuarine walkover surveys are presented in Table 10.6, along with a range of other information relating to the conservation status of each species and 1% national thresholds.

For bird species that are not qualifying species of the Baldoyle Bay SPA, peak counts by month for the entire estuarine survey programme are presented in Table A10.4 of Appendix A10.1. Table 10.7 ranks these species by peak count, as well as providing a range of conservation information and 1% national thresholds where available. Corresponding international thresholds are presented if they were available when 1% national thresholds were not. Figures A10.1 to A10.53 in Appendix A10.1 show the distribution of various species of birds across the Baldoyle Bay estuarine survey area (Figure 10.1 Location and Extent of Marine, Coastal and Estuarine Ornithological Surveys) recorded during the estuarine walkover surveys. Distribution of the SCIs of the Baldoyle Bay SPA are presented in Figures A10.1 to A10.6, whilst the distribution of other species included on the Natura 2000 data form are presented in Figures A10.7 to A10.22. Figures A10.23 to A10.53 contain the distributions of species that were recorded during the estuarine walkover surveys that are not included on the

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Natura 2000 data form for the Baldoyle Bay SPA. They are ordered as per the species groupings in Table A10.4 of Appendix A10.1. Figures were produced for species that are named on citations of the Ireland’s Eye SPA or Howth Head Coast SPA, or for other species if more than 10 records of the species were made during the surveys. Special Conservation Interests of the Baldoyle Bay Special Protection Area

Light-bellied brent goose was present in peak numbers during the wintering and passage periods, and was generally absent during the breeding season (April to August) (Appendix A10.1, Table A10.2). The two-year peak mean was 816 birds, exceeding the 1% national threshold of 360 birds and the 1% international threshold of 400 birds. Brent geese were observed across the surveyed section of the SPA and on both the seaward and landward sides of the estuary. It should be noted that almost all of these records were of birds in flight (Figure A10.2, Appendix A10.1). Within the SPA, birds were frequently seen in association with wetted channels, where they were observed feeding, loafing and bathing. Birds were observed roosting in the north, west and east of the section of the SPA that was surveyed. Shelduck was present in the estuarine survey area all year round (Appendix A10.1, Table A10.2). Peaks in the population size occurred over winter, but birds were also present in reasonable numbers during the breeding season. This suggests a small resident population which is swelled by additional wintering birds. The two-year peak mean of 138 birds exceeds the 1% national threshold of 120 birds, but not the 1% international threshold of 3,000 birds. Shelducks were distributed relatively evenly throughout the wetted portion of the SPA covered by the surveys, and were infrequently recorded in association with habitats beyond the SPA (Figure A10.6, Appendix A10.1). They were frequently seen individually or in small groups.

Bar-tailed godwit was present in peak numbers during the wintering and passage periods, and in low numbers during the breeding season. The two-year peak mean was 275 birds, exceeding the 1% national threshold of 150 birds, but not the 1% international threshold of 1,200 birds. Bar-tailed godwit records were predominantly located within the intertidal area of Baldoyle Bay SPA (Figure A10.1, Appendix A10.1). Small numbers of birds were recorded in the intertidal area of Velvet Strand Beach to the east of the SPA, and a single record was made in a field to the north of the R123 Moyne Road, west of the SPA. Over two-thirds of records were feeding birds, with roosting on the estuary fringes the next most commonly recorded behaviour. The main roosting locations were areas in the north and north-west of the SPA, with some roosting birds recorded at the western shoreline of the SPA.

Ringed plover numbers peaked during the autumn passage and winter periods in 2015/2016, and were also regularly recorded during the breeding season (Appendix A10.1, Table A10.2). The two-year peak mean of 204 birds exceeded the 1% national threshold of 100 birds, but not the 1% international threshold of 730 birds. This species showed a preference for the habitats associated with the eastern side of the Baldoyle Bay SPA (Figure A10.5, Appendix A10.1). As well as being recorded within the SPA, relatively substantial numbers of records were made on the land to the western side of the Portmarnock Golf Course, and a smaller number of birds were recorded on the course itself. A handful of records were also made in the Velvet Strand Beach intertidal area to the east of the SPA. Grey plover was present in peak numbers during the passage periods, and was generally absent during the breeding season. In the winter, it was only present in low numbers (Appendix A10.1, Table A10.2). Because of the large passage peaks (two-year peak mean of 487 birds), the 1% national threshold of 30 birds was exceeded by a large amount. The 1% international threshold of 2,500 birds was not exceeded. Grey plovers were observed within the estuarine survey area almost exclusively within the Baldoyle Bay SPA (Figure A10.4, Appendix A10.1). This species showed a preference for habitat to the eastern side of the Baldoyle Bay, though records were made across the estuary of birds feeding, roosting and loafing.

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Golden plover, like grey plover, was present in peak numbers during the wintering and passage periods and was generally absent during the breeding season. The two-year peak mean of 3,061 birds exceeded the 1% national threshold of 1,200 birds, but not the 1% international threshold of 9,300 birds. There were comparatively few records of golden plover during the estuarine surveys, though when recorded, birds were present in large groups of up to 3,300 birds (Figure A10.3, Appendix A10.1). Most observations of this species were made within the Baldoyle Bay SPA boundary, though some groups of birds were recorded in the field to the west. Several groups of roosting birds were recorded towards the north of the estuary. Other Named Qualifying Species of the Baldoyle Bay SPA

The other qualifying species listed in the Natura 2000 data form for the Baldoyle Bay SPA can be grouped into three broad categories of temporal distribution.

 Species that were absent during the breeding season, with peaks in the population occurring in the winter or passage seasons: great-crested grebe, knot, pintail, red-breasted merganser and sanderling. Great-crested grebes were recorded on just three occasions within the Baldoyle Bay SPA. All other records were made in the intertidal area to the east of the SPA at Velvet Strand, where birds were recorded feeding and loafing (Figure A10.10, Appendix A10.1). The two-year peak mean of 44 birds exceeded the 1% national threshold of 40 birds, but fell well short of the 1% international threshold of 3,500 birds.

Knots were recorded in low numbers and favoured the area of Baldoyle Bay several hundred metres to the south of the microtunnelled section of the proposed outfall pipeline route (marine section), where they were recorded feeding and roosting (Figure A10.13, Appendix A10.1). The two-year peak mean of 126 birds did not exceed the 1% national threshold of 280 birds. Only two records of pintails were made during the estuarine surveys (Figure A10.17, Appendix A10.1). Both were made within the Baldoyle Bay SPA boundary, just to the south of the proposed microtunnelled section of the proposed outfall pipeline route (marine section). The 1% national threshold of 20 birds was not exceeded. Red-breasted mergansers were observed feeding within the SPA boundary, with the majority of records made in the southern portion of the estuarine survey area (Figure A10.18, Appendix A10.1). There were greater numbers of records of this species in the sea off Velvet Strand to the east of the Baldoyle Bay SPA than in the SPA itself. The two-year peak mean was 26 birds, which exceeded the 1% national threshold of 20 birds. The 1% international threshold of 1,700 birds was not exceeded.

Sanderlings were recorded infrequently during the estuarine surveys, with only a single record of this species made within the Baldoyle Bay SPA (Figure A10.20, Appendix A10.1). All other records of this species were made in the intertidal area of Velvet Strand to the east of the Baldoyle Bay SPA. The two-year peak mean of 50 birds was below the 1% national threshold of 60 birds.

 Species that were present in low/very low numbers of non-breeding/early returning birds during the breeding season, with peaks in the population occurring in the winter or passage seasons: black-tailed godwit, dunlin, greenshank, lapwing, redshank, teal and turnstone. Black-tailed godwits were recorded in relatively modest numbers during the estuarine surveys, and were located almost exclusively within the Baldoyle Bay SPA (Figure A10.7, Appendix A10.1). Birds were recorded on the fringes of the SPA slightly more often than in the middle of it. The 1% national threshold of 190 was greater than the two-year peak mean of 166 birds. The two-year peak mean also did not exceed the 1% international threshold of 610 birds.

Dunlins were frequently recorded in the Baldoyle Bay SPA, with the majority of sightings made to the south of the proposed outfall pipeline route (marine section) (Figure A10.9, Appendix A10.1). Small numbers of birds

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were also observed in the northern area of the SPA and in the intertidal area to the east. The two-year peak mean of 525 birds was below the 1% national threshold of 570 birds.

Greenshanks were recorded feeding and roosting predominantly in the Baldoyle Bay SPA to the south of the microtunnelled section of the proposed outfall pipeline route (marine section) (Figure A10.11, Appendix A10.1). No birds were recorded in terrestrial habitats. The two-year peak mean for greenshank was 20 birds, which is equal to the 1% national threshold.

Lapwings were recorded in the Baldoyle Bay SPA and terrestrial habitats to the west (Figure A10.14, Appendix A10.1). Within the SPA close to the mouth of the Mayne River, there were numerous records of this species. Birds recorded in the fields to the west of the estuary included several pairs holding breeding territories, and birds also feeding and roosting. The two-year peak mean of 534 birds was lower than the 1% national threshold of 1,100 birds.

Redshanks were recorded across the estuarine section of the estuarine survey area, utilising numerous areas for feeding, loafing and roosting (Figure A10.19, Appendix A10.1). Most observations throughout the SPA were associated with river channels or the saltmarsh areas at the fringe of the intertidal flats. To the south of the proposed microtunnelled section of the proposed outfall pipeline route (marine section), records were concentrated to the eastern and western margins of the Baldoyle Bay SPA. Small numbers of records were made in the sea off Velvet Strand. The two-year peak mean of 294 birds was lower than the 1% national threshold of 300 birds.

Teals were most frequently associated with river channels in both the estuary itself, but also upstream (Figure A10.21, Appendix A10.1). There was a concentration of records within the Baldoyle Bay SPA towards the western edge. The two-year peak mean of 328 birds was lower than the 1% national threshold of 340 birds.

Turnstones were recorded infrequently, with records distributed across the Baldoyle Bay SPA section of the estuarine survey area (Figure A10.22, Appendix A10.1). A small number of records were also made on the intertidal area to the east of the SPA. The two-year peak mean of 74 birds was lower than the 1% national threshold of 95 birds.

 Species that are present in larger numbers throughout the year, with peaks in the population occurring in the winter or passage seasons: curlew, grey heron, mallard and oystercatcher. There may be small resident populations of these species, which increase in the winter as birds which have spent the breeding seasons elsewhere arrive to Baldoyle Bay. Curlews were distributed fairly evenly throughout the Baldoyle Bay SPA, with birds recorded feeding and roosting across the SPA habitat (Figure A10.8, Appendix A10.1). There were small numbers of birds recorded in the fields to the west of the SPA, on Portmarnock Golf Course to the east, and in the intertidal area to the east of the SPA. The two-year peak mean of 164 birds was lower than the 1% national threshold of 350 birds.

Grey herons were recorded primarily in association with the Mayne River and other watercourses to the west of the Baldoyle Bay SPA. They were also recorded frequently in the north-west corner of the Baldoyle Bay SPA (Figure A10.12, Appendix A10.1), and in modest numbers across the Baldoyle Bay SPA itself, particularly on the western and eastern fringes of the SPA. The two-year peak mean of 15 birds was lower than the 1% national threshold of 25 birds. Mallards were recorded across the Baldoyle Bay Estuary and surrounding habitats, with several ‘hotspots’ where numbers of records were much higher (Figure A10.15, Appendix A10.1). These hotspots were used for feeding and roosting, and were generally located close to the estuary and SPA edges where rivers flow into it. They were also seen regularly on the Mayne River to the west of the SPA. Substantial numbers were

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recorded on the Portmarnock Golf Course to the east of the SPA in association with water bodies. The two- year peak mean of 185 birds was lower than the 1% national threshold of 290 birds.

Oystercatchers were most frequently recorded within the SPA boundary to the south of the microtunnelled section of the proposed outfall pipeline route (marine section) (Figure A10.16, Appendix A10.1). In addition, birds were recorded frequently on Portmarnock Golf Course feeding and roosting, and substantial numbers were also observed feeding in the intertidal zone to the east of Portmarnock Golf Course and the SPA at Velvet Strand. The peak count over two years of 739 birds exceeded the 1% national threshold of 690 birds, but not the international threshold of 8,200 birds.

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Table 10.6: Species Listed on the Baldoyle Bay Special Protection Area Citation Recorded During Baseline Estuarine Surveys

Species Common Baldoyle Annex I BoCCI Recent Site Site Site 1% 1% All Two-Year Peak Name Bay SPA Species Status** Five- Population Population Conservation International Ireland Peak Mean Months Qualifying Year Trend (Five Trend (12 Condition Threshold*** Threshold During Species* Mean (i) Year) Year) *** Baseline Surveys**** Branta bernicla Brent goose SCI No Amber 874 +30.0 +43.7 Favourable 400 360 816 Feb 2016 (w) Dec 2017 Tadorna Shelduck SCI No Amber 290 +118.1 +141.5 Favourable 3,000 120 138 Jan 2015 tadorna (b,w) Dec 2015 Charadrius Ringed plover SCI No Green 122 -4.3 -7.3 Intermediate 730 100 204 Sept 2015 hiaticula Unfavourable Nov 2017 Pluvialis Grey plover SCI No Amber 96 -53.6 -49.3 Unfavourable 2,500 30 487 Mar 2015 squatarola (w) Mar 2016 Pluvialis Golden SCI Yes Red 914 -1.6 -37.7 Unfavourable 9,300 1,200 3,061 Jan 2015 apricaria plover (b,w) Feb 2018 Limosa Bar-tailed SCI Yes Amber 134 -7.4 -52.8 Highly 1,200 150 275 Nov 2015 lapponica godwit (w) Unfavourable Nov 2017 Podiceps Great-crested Yes No Amber 29 - - - 3,500 40 44 Nov 2015 cristatus grebe (b,w) Feb 2018 Anas crecca Teal Yes No Amber 238 - - - 5,000 340 328 Feb 2016 (b,w) Feb 2018 Anas Mallard Yes No Green 212 - - - 45,000 290 185 Jan 2015 platyrhynchos Sept 2015 Anas acuta Pintail Yes No Red (w) 26 - - - 600 20 1 Jan 2015 Mergus serrator Red-breasted Yes No Green 17 - - - 1,700 20 26 Nov 2015 merganser Apr 2017 Haematopus Oystercatche Yes No Amber 837 - - - 8,200 690 739 Mar 2015 ostralegus r (b,w) Sept 2015 Vanellus Lapwing Yes No Red 365 - - - 20,000 1,100 534 Jan 2016 vanellus (b,w) Feb 2018 Calidris Knot Yes No Amber 111 - - - 4,500 280 126 Feb 2015 canutus (w) Feb 2016 Calidris alpina Dunlin Yes No Red 185 - - - 13,300 570 525 Dec 2015 (b,w) Dec 2017 Limosa limosa Black-tailed Yes No Amber 204 - - - 610 190 166 Mar 2015

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Species Common Baldoyle Annex I BoCCI Recent Site Site Site 1% 1% All Two-Year Peak Name Bay SPA Species Status** Five- Population Population Conservation International Ireland Peak Mean Months Qualifying Year Trend (Five Trend (12 Condition Threshold*** Threshold During Species* Mean (i) Year) Year) *** Baseline Surveys**** godwit (w) Mar 2018 Numenius Curlew Yes No Red 130 - - - 8,400 350 164 Sept 2015 arquata (b,w) Feb 2016 Tringa totanus Redshank Yes No Red 314 - - - 2,400 300 294 Dec 2015 (b,w) Dec 2017 Tringa Greenshank Yes No Green 20 - - - 2,300 20 12 Mar 2015 nebularia Sept 2017 Arenaria Turnstone Yes No Green 77 - - - 1,400 95 74 Dec 2015 interpres Mar 2017 Calidris alba Sanderling Yes No Green 21 - - - 1,200 60 50 Mar 2016 Nov 2017 Ardea cinerea Grey heron Yes**** No Green 16 - - - 2,700 25 15 Dec 2015 Nov 2017 Notes *SCI = Special Conservation Interest, Yes = Named Natura 2000 Species **b = breeding, w = wintering ***Taken from I-WeBS 2018 and British Trust for Ornothology2018 if no data from I-WeBS. ****Highest peak in a single survey recorded during estuarine surveys. *****Species of interest only.

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Other Bird Species Auks, which are SCIs and/or qualifying species of the Ireland’s Eye SPA and Howth Head Coast SPA, were recorded in very low numbers within Baldoyle Bay. Birds were recorded during the winter/passage period and the late summer following either failed breeding or fledging (Table A10.4, Appendix A10.1). The peak count was 20 for common guillemot, six for razorbill and four for black guillemot. Records of auks within the Baldoyle Bay SPA were rare, with just three guillemot observations recorded (Figure A10.24, Appendix A10.1). Black guillemot (Figure A10.23, Appendix A10.1) and razorbill (Figure A10.25, Appendix A10.1) were only recorded in the sea off the Velvet Strand Beach. Given that these groups of birds are seabirds and are not primarily associated with estuaries, it is not considered that Baldoyle Bay is a habitat of great importance to auks.

Divers were recorded in relatively low numbers during the wintering and passage periods (September to March) (Table A10.4, Appendix A10.1). There were odd individuals present during the breeding season. All great northern diver records (Figure A10.26, Appendix A10.1) and all but two red-throated diver records (Figure A10.27, Appendix A10.1) were recorded in the sea off the Velvet Strand Beach. The peak counts were 16 for red-throated diver and six for great northern diver and did not exceed the 1% national thresholds for these species (20 and 25 respectively). Given that these groups of birds are seabirds except when breeding, and are not primarily associated with estuaries, it is not considered that Baldoyle Bay is a habitat of great importance to them. Two of the three geese and swan species recorded were only observed during passage periods. Seventy- three Canada geese were observed on two occasions, with a lone pink-footed goose being observed once throughout the surveys. On this basis, it appears these species are occasional visitors. Mute swans were present at Baldoyle Bay in low numbers throughout the year, suggesting a small resident population. They were recorded in association with river channels (Figure A10.28, Appendix A10.1), with records more frequent at the mouths of the Sluice River in the north of Baldoyle Bay, and the Mayne River. Wigeon was regularly recorded in relatively large numbers during the winter and passage periods. Records were confined to within the Baldoyle Bay SPA boundary (Figure A10.33, Appendix A10.1). The peak of 257 birds did not exceed the 1% national threshold of 630 birds. The species was largely absent from the estuarine survey area in May, June and July, but present in more substantial numbers for the other months.

Duck species recorded on a single occasion only were eider (two-year peak of three birds), goldeneye (two- year peak of eight birds) and shoveler (two-year peak of two birds). Long-tailed duck and tufted duck were present slightly more regularly, but only in small numbers.

Common scoters were recorded in relatively large numbers during the spring and autumn passage periods. The peak count of 233 birds exceeds the 1% national threshold of 140 birds. No common scoters were recorded in Baldoyle Bay; all records were made in the sea off Velvet Strand (Figure A10.29, Appendix A10.1).

Coot, moorhen and little grebe were recorded in low numbers throughout the year, suggesting the presence of small resident populations (Table A10.4, Appendix A10.1). Coots were only observed in association with freshwater habitats (Figure A10.30, Appendix A10.1), and little grebes were located predominantly in association with water features on the Portmarnock Golf Course (Figure A10.31, Appendix A10.1). The distribution of moorhens was similar (Figure A10.32, Appendix A10.1). Black-necked grebes were recorded once during the survey programme (Table A10.4, Appendix A10.1). The 1% national thresholds were not reached for any of these species.

Five species of gull were recorded throughout the year: black-headed gull (Figure A10.34, Appendix A10.1), common gull (Figure A10.35, Appendix A10.1), great black-backed gull (Figure A10.36, Appendix A10.1),

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herring gull (Figure A10.37, Appendix A10.1) and lesser black-backed gull (Figure A10.39, Appendix A10.1). Of these, herring gull is an SCI of the Ireland’s Eye SPA, with great black-backed gull a named qualifying species. These commonly encountered gull species were recorded across many habitats found within the estuarine survey area. They are highly adaptable birds and will utilise a range of coastal, inland and offshore habitats. Kittiwake (Figure A10.38, Appendix A10.1), Mediterranean (Figure A10.51, Appendix A10.1) and ring-billed gulls were very occasional visitors and were recorded in low numbers. National population estimates were not available for these species. Cormorant (an SCI of the Ireland’s Eye SPA) and shag were recorded regularly, but in low numbers throughout most of year, with cormorants being the more commonly encountered of the two species (Table A10.4, Appendix A10.1). The presence of these species is common in coastal locations. Whilst shags (Figure A10.44, Appendix A10.1) were recorded only in the sea off Velvet Strand, cormorants (Figure A10.43, Appendix A10.1) were recorded both off Velvet Strand and in the Baldoyle Bay SPA. The 1% national threshold was not exceeded for either species. Four species of raptor were occasionally observed during the estuarine surveys (Table A10.4, Appendix A10.1). Buzzards and peregrines (the latter being an SCI of the Howth Head Coast SPA) were the most frequent and numerous raptors recorded. Buzzard records were largely confined to the open fields to the east of the Baldoyle Bay SPA, with a further three records made over Portmarnock Golf Course (Figure A10.41, Appendix A10.1). Peregrines were recorded predominantly to the eastern edge of the Baldoyle Bay SPA, though 10 records across the whole survey programme suggests Baldoyle Bay is of limited importance overall to this species (Figure A10.42, Appendix A10.1). All raptor records were of birds in flight. Other species recorded were kestrel (Figure A10.50, Appendix A10.1) and sparrowhawk.

Five species of tern were recorded within the Baldoyle Bay SPA between March and September each year (Table A10.4, Appendix A10.1). Of these, common and Sandwich tern were the most abundant, with Arctic, black and roseate (Figure A10.52, Appendix A10.1) terns only recorded in low numbers. It is likely that these were either foraging birds from local breeding colonies or birds on passage. The two most frequently recorded tern species, common tern (Figure A10.45, Appendix A10.1) and Sandwich tern (Figure A10.46, Appendix A10.1), were recorded almost exclusively off the coast of Velvet Strand. Only four records in total of both species were made within the Baldoyle Bay SPA. Several species of non-breeding wader were recorded in Baldoyle Bay, usually in small numbers (<10) (Table A10.4, Appendix A10.1). The three most commonly recorded were whimbrel, common snipe and common sandpiper. Whimbrel had a peak count of 76 in spring, with records distributed across the Baldoyle Bay SPA (Figure A10.49, Appendix A10.1). Common snipe was recorded at the fringes of the Baldoyle Bay SPA, and on the fields to the east of the SPA boundary (Figure A10.48, Appendix A10.1). Common sandpiper was most numerous at the mouth of the Sluice River (Figure A10.47, Appendix A10.1). Other wading species which were occasionally recorded and in low numbers were curlew sandpiper (two-year peak of six birds), ruff (two- year peak of eight birds; Figure A10.53, Appendix A10.1), purple sandpiper (two-year peak of two birds) and little stint (two-year peak of one bird). Avocet and green sandpipers were both recorded once during the survey programme (Table A10.4, Appendix A10.1).

Little egrets were recorded throughout the intertidal area of the estuarine survey area (Figure A10.40, Appendix A10.1). The two-year peak for this species was 20 birds during the passage season, but smaller numbers were recorded throughout the year.

Other species recorded only once during the surveys were snow bunting (two-year peak of six birds), hooded crow (two-year peak of four birds) and stonechat (two-year peak of 11 birds). A single individual of the

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following species was seen only once: blue tit, fulmar, kingfisher, mistle thrush, pheasant, red-legged partridge, song thrush and wheatear.

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Table 10.7: Species Not Listed on the Baldoyle Bay Special Protection Area Citation Recorded During Baseline Estuarine Surveys

Species Common Name Ireland's Howth Annex I BoCCI Status Two-Year Peak All Ireland Month in Which Eye SPA Head Coast Species During Baseline Threshold** Peak Recorded Qualifying SPA Surveys* Species Qualifying Species Chroicocephalus ridibundus Black-headed gull Red (b) 404 22,000*** Sept Larus argentatus Herring gull** SCI Yes Red (b) 331 7300*** Sept Anas penelope Wigeon Red (w) 257 630 Dec Melanitta nigra Common scoter Red (b) 233 140 Nov Larus canus Common gull Amber (b) 84 16,400*** Feb Numenius phaeopus Whimbrel Green 76 6,700*** May Branta canadensis Canada goose Green 73 - Jan Larus marinus Great black-backed gull** Yes Amber (b) 69 4,200*** Sept Larus fuscus Lesser black-backed gull Amber (b) 46 5,500*** Jun Phalacrocorax carbo Cormorant SCI Amber (b,w) 42 120 Oct Sterna sandvicensis Sandwich tern Yes Amber (b) 42 1,700*** Aug Gallinago gallinago Snipe Amber (b,w) 35 20,000*** Feb Sterna hirundo Common tern Yes Amber (b) 34 1,800*** Aug Uria aalge Guillemot*,*** SCI Yes Amber (b) 20 - Dec Egretta garzetta Little egret Green 20 20 Sept Gavia stellata Red-throated diver Yes Amber (b) 16 20 Mar and Oct Cygnus olor Mute swan Amber (b,w) 15 90 Aug Podiceps nigricollis Black-necked grebe Red (w) 14 - Nov Gallinula chloropus Moorhen Green 12 20 Apr Saxicola torquatus Stonechat Green 11 - Jan Phalacrocorax aristotelis Shag** Yes Amber (b) 11 2,000*** Oct Sterna dougallii Roseate tern Yes Amber (b) 11 - Jul Bucephala clangula Goldeneye Red (w) 8 60 Jan Philomachus pugnax Ruff Yes Amber (passage) 5 8*** Sept Alca torda Razorbill*,*** SCI Yes Amber (b) 6 - May Gavia immer Great northern diver Yes Amber (w) 6 20*** Nov Rissa tridactyla Kittiwake*,*** SCI SCI Amber (b) 6 20,000*** Mar Plectrophenax nivalis Snow bunting Green 6 - Apr Calidris ferruginea Curlew sandpiper Green 6 10,000*** Nov Tachybaptus ruficollis Little grebe Amber (b,w) 5 20 Jun Sterna paradisaea Arctic tern Yes Amber (b) 5 20,000*** Jun Cepphus grylle Black guillemot** Yes Amber (b) 4 - Apr and Oct Fulica atra Coot Amber (b,w) 4 220 Apr Clangula hyemalis Long-tailed duck Red (w) 4 110 Jan Ichthyaetus melanocephalus Mediterranean gull Yes Amber (b) 4 770*** Sept Corvus cornix Hooded crow Green 4 - May

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Species Common Name Ireland's Howth Annex I BoCCI Status Two-Year Peak All Ireland Month in Which Eye SPA Head Coast Species During Baseline Threshold** Peak Recorded Qualifying SPA Surveys* Species Qualifying Species Somateria mollissima Eider Amber (b,w) 3 35 Apr Buteo Buzzard Green 3 - May Actitis hypoleucos Common sandpiper Amber (b) 3 - Apr and Sept Anas clypeata Shoveler Red (w) 2 30 Nov Falco tinnunculus Kestrel Amber (b) 2 - Aug Falco peregrinus Peregrine*,*** Yes Yes Green 2 - Feb and Apr Chlidonias niger Black tern Yes Green 2 7,100*** Aug Calidris maritima Purple sandpiper Green 2 20 Mar Anser brachyrhynchus Pink-footed goose Green 1 3,500*** Mar Aythya fuligula Tufted duck Red (w) 1 310 Jan, Feb, Jul and Nov Larus delawarensis Ring-billed gull Green 1 - Jan and Mar Cyanistes caeruleus Blue tit Green 1 - Feb Fulmarus glacialis Fulmar Yes Yes Green 1 - Dec Alcedo atthis Kingfisher Yes Amber (b) 1 - Dec Turdus viscivorus Mistle thrush Amber (b) 1 - Mar Phasianus colchicus Pheasant Green 1 - May Alectoris rufa Red-legged partridge Green 1 - Feb Turdus philomelos Song thrush Green 1 - Mar Oenanthe oenanthe Wheatear Amber (b) 1 - May Accipiter nisus Sparrowhawk Amber (b) 1 - Mar, Sept, Oct and Nov Recurvirostra avosetta Avocet Yes Green 1 75*** Apr Calidris minuta Little stint Green 1 - Aug Notes *Highest peak recorded during estuarine surveys. **Taken from I-WeBS 2018 and British Trust for Ornothology 2018 if no data from I-WeBS. ***International 1% threshold, used when no all-Ireland threshold available.

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10.3.4 Marine Birds and Related Special Protection Areas in the Vicinity of Dublin Bay There are several breeding seabird colonies of international and national importance located near the proposed outfall pipeline route (marine section) (including the proposed marine diffuser):

 Ireland’s Eye SPA, 1km south;  Howth Head Coast SPA, 2.6km south;  Lambay Island SPA, 9.3km north-east;  Skerries Island SPA, 16.7km north; and  Rockabill SPA, 16.9km north. The closest SPAs with seabirds listed as Natura 2000 species or species of SCI are the Ireland’s Eye and Howth Head Coast SPAs. Details associated with these SPAs, which were taken from conservation objectives and Natura 2000 forms, are presented in Table 10.8, along with the peak VP survey count from a single survey.

Table 10.8: Species Included on Citations of Ireland’s Eye and Howth Head Coast Special Protection Areas and Single Peak Vantage Point Survey Counts Recorded During Baseline Surveys

Species Common Listed on Annex I Ireland’s Eye Special Howth Head Coast Special Single Name Protection Area Protection Area Survey of Directive Peak 2009/147/EC of Special Special Special Special Count Conservation Protection Conservation Protection the European Interest? Area Interest? Area Parliament and of Population at Population at the Council of 30 Citation Citation November 2009 on the conservation of wild birds

Rissa Kittiwake No Yes 941 pairs Yes 2,329 pairs 557 tridactyla Uria aalge Common No Yes 2,191 - 995 1,513 guillemot individuals individuals Alca torda Razorbill No Yes 522 individuals - 416 1,038 individuals Phalacrocora Cormorant No Yes 306 pairs - - 69 x carbo Larus Herring gull No Yes 250 pairs - - 239 argentatus Falco Peregrine Yes - 1 pair - 1 pair 4 peregrinus Fulmarus Fulmar No - 70 pairs - 33 pairs 159 glacialis Morus Gannet No - 142 pairs - - 225 bassanus Fratercula Puffin No - 10–20 - - 173 arctica individuals Phalacrocora Shag No - 32 pairs - - 129 x aristotelis

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Species Common Listed on Annex I Ireland’s Eye Special Howth Head Coast Special Single Name Protection Area Protection Area Survey of Directive Peak 2009/147/EC of Special Special Special Special Count Conservation Protection Conservation Protection the European Interest? Area Interest? Area Parliament and of Population at Population at the Council of 30 Citation Citation November 2009 on the conservation of wild birds

Larus Great No - 100 pairs - - 97 marinus black- backed gull Cepphus Black No - 15 individuals - - 22 grylle guillemot

During the breeding season, the distribution of foraging seabirds at sea is likely influenced by the location of their breeding colonies and competition with other birds (from both the same and other colonies). In addition, the characteristics of the marine environment which denote productivity, including water depth, surface salinity and temperature, the location of tidal fronts and areas of upwelling may also influence the distribution of foraging seabirds (Wakefield et al. 2017).

10.3.5 Marine Birds Ornithological Baseline Sources of Information

Tables A10.6 and A10.10 in Appendix A10.1 provide information on the bird species of the Ireland’s Eye and Howth Head Coast SPAs recorded during VP surveys for the breeding season (April to August) (Table A10.10, Appendix A10.1) and wintering season (September to March) (Table A10.6, Appendix A10.1), respectively. Presented is the number of observations of each species (i.e. a measure of how often a species was recorded), the total number of each species recorded in flight and on the sea, the peak count of each species recorded in flight and on the sea during a single survey, and an overall peak count (i.e. the maximum number of individuals seen during a single survey). In addition, graphs are presented in Appendix A10.1 which illustrate a range of temporal patterns for each species that are important. The distribution of SPA qualifying marine bird species from the Ireland’s Eye VP during the breeding season is presented in Figure A10.54 to Figure A10.65 of Appendix A10.1. The figures focus on birds recorded on the water. Findings are discussed by species below, but in general, birds were recorded in most VP viewing arc sectors.

Tables A10.7 and A10.11 in Appendix A10.1 provide information on Baldoyle Bay SPA qualifying species recorded during VP surveys for the breeding (April to August) (Table A10.11, Appendix A10.1) and wintering (September to March) (Table A10.7, Appendix A10.1) seasons respectively. Presented is the number of observations of each species (i.e. a measure of how often a species was recorded), the total number of each species recorded in flight and on the sea, the peak count of each species recorded in flight and on the sea during a single survey, and an overall peak count (i.e. the maximum number of individuals seen during a single survey). In addition, graphs are presented in Appendix A10.1 which illustrate a range of temporal patterns that are

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considered to be important. Graphs have been produced for species where greater than 50 birds were observed on the sea during either the breeding or the wintering season.

Appendix A10.1 provides information on non-designated marine bird species recorded during VP surveys for the breeding (April to August) (Table A10.12, Appendix A10.1) and wintering (September to March) (Table A10.8/9, Appendix A10.1) seasons respectively. Presented is the number of observations of each species (i.e. a measure of how often a species was recorded), the total number of each species recorded in flight and on the sea, the peak count of each species recorded in flight and on the sea during a single survey, and an overall peak count (i.e. the maximum number of individuals seen during a single survey). In addition, graphs are presented in Appendix A10.1 which illustrate a range of temporal patterns that are important. Graphs have been produced for species where greater than 50 birds were observed on the sea during either the breeding or the wintering season. Although Canada goose met these criteria (peak count of 207 birds), a graph was excluded on the grounds that it was only observed in January (Table A10.8, Appendix A10.1).

Tables A10.13 to A10.40 in Appendix A10.1 provide details on the distribution of birds recorded during VP surveys between March and October of all survey years. Records are split by VP, distance from the observer, and the behaviour code assigned to each record. These tables do not contain records of birds in flight.

Where time periods describe when a species was present, this refers to all years unless otherwise stated. Special Conservation Interests of the Ireland’s Eye Special Protection Area and/or Howth Head Coast Special Protection Area

Kittiwake is the only species named as an SCI at both the Ireland’s Eye and Howth Head Coast SPAs. Kittiwakes were observed throughout the breeding season, but in highest numbers in May (Table A10.10, Appendix A10.1). The peak single survey count was 557 birds (Table A10.10, Appendix A10.1). In all survey years, a substantial decrease in numbers of birds was observed in August (Graph A10.2, Appendix A10.1). Numbers then remained low until around February, before increasing again in March. Of the 4,195 kittiwakes observed on the sea between March and October, 3,627 (86.5%) were recorded from VP2 on Ireland’s Eye (Table A10.13, Appendix A10.1). Of these, 2,812 birds (77.5%) were recorded loafing. Records of kittiwakes on the water were distributed more to the east of the Ireland’s Eye VP viewing arc, and in general, the sectors in which most birds were recorded were situated further away from Ireland’s Eye (Figure A10.62, Appendix A10.1).

During the breeding season, the species that were recorded in the highest numbers were guillemot and razorbill. Both species are SCIs of the Ireland’s Eye SPA, and Natura 2000 species of the Howth Head Coast SPA. Peak numbers of both species were observed in May, with high numbers of records in June and July. The peak single survey count was 1,513 for guillemot and 1,038 for razorbill (Table A10.10, Appendix A10.1). In total, around 80% of birds from both species that were recorded during VP surveys were observed during these months (Graph A10.1, Appendix A10.1). By August, observations of these species had substantially reduced which remained the case during the winter. Numbers began to increase in March and April, with a slight increase in razorbill observations in February (Graph A10.1, Appendix A10.1). In addition, substantial numbers of guillemots or razorbills that were not identified to species level were also recorded (Table A10.10, Appendix A10.1). This is because, at the edge of the viewing arc (i.e. nearly 2km from the observer), birds were routinely detected, but identification was more difficult than when birds were closer (Figure A10.60, Appendix A10.1).

The vast majority of guillemots (Table A10.14, Appendix A10.1) and razorbills (Table A10.15, Appendix A10.1) were recorded on the sea between March and October from VP2 on Ireland’s Eye (8,186 of 8,966 (91.3%)

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guillemots and 7,449 of 8,240 (90.4%) razorbills). Of these observations, 80.1% of guillemots and 79.6% of razorbills were observed loafing. Feeding behaviour accounted for only 14.0% of guillemots and 13.1% of razorbills recorded on the sea from the Ireland’s Eye VP. Both guillemots (Figure A10.59, Appendix A10.1) and razorbills (Figure A10.64, Appendix A10.1) were recorded in the main within 500m of the Ireland’s Eye VP, but also in relatively large numbers between 500m and 1,000m away from the VP. The most frequently recorded behaviour of both species were non-feeding (generally loafing) birds most often recorded within 500m of the Ireland’s Eye VP (Figure 10.5 Distribution of Non-Feeding Guillemot Records from Ireland’s Eye Vantage Point during Breeding Season (March to October) for guillemot and Figure 10.7 Distribution of Non-Feeding Razorbill Records from Ireland’s Eye Vantage Point during Breeding Season (March to October) for razorbill). The distribution of feeding guillemot and razorbill records are illustrated in Figure 10.4 Distribution of Feeding Guillemot Records from Ireland’s Eye Vantage Point during Breeding Season (March to October) and Figure 10.6 Distribution of Feeding Razorbill Records from Ireland’s Eye Vantage Point during Breeding Season (March to October). Boat based surveys in July of 2016 and 2017 revealed that fledged chicks were present on cliffs and not in the water until mid-July. At this point, numbers of guillemots and razorbills on nests on the cliffs rapidly declined; however, no rafts of fledged chicks (or adults) were observed on the water around Ireland’s Eye at any time. By the final week of July, most guillemots and razorbills had left the area without massing of large numbers of birds in the water being recorded. Survey observations suggest that, rather than spending time on the water around the island, guillemots and razorbills leave the nest only when they intend to leave the area, and leave in small groups. Based on the lack of movements of large rafts of birds recorded, it is possible that some movements occur at night.

Herring gulls are an SCI of the Ireland’s Eye SPA. They were observed throughout the breeding season, with numbers peaking in July (Graph A10.2, Appendix A10.1), though numbers in May and June were also high (the peak number of birds recorded in a single survey occurred in June). Lower numbers of birds were present in the area for much of the year (Graph A10.2, Appendix A10.1). The peak single monthly count was 185 birds during the breeding season (Table A10.10, Appendix A10.1), and 239 birds overall (Table A10.6, Appendix A10.1). Both VPs recorded a similar number of birds on the water between March and October, with the majority of birds recorded either roosting on the water or loafing (Table A10.16, Appendix A10.1). Birds on the water were distributed quite evenly throughout the VP viewing arcs, though the most birds occurred within 0m to 500m of Ireland’s Eye. Records on the water from VP2 (Ireland’s Eye) were quite heavily restricted to western VP sectors within 1,000m of the VP (Figure A10.61, Appendix A10.1). Cormorants are an SCI of the Ireland’s Eye SPA and were recorded most frequently during the breeding season (Graph A10.4, Appendix A10.1). Cormorant records during the breeding season were the most numerous in May, June and July, with a single monthly peak of 63 birds (Table A10.10, Appendix A10.1). The maximum winter peak was 69 birds (Table A10.6, Appendix A10.1). Between March and October, birds were recorded on the water most frequently in distances bands 1 and 2 from both VPs (Table A10.17, Appendix A10.1). Birds were recorded behaving in a variety of ways (feeding, preening, loafing and roosting) across the entire VP survey area. Birds were observed most frequently in VP1 sectors ending with the letter F, indicating a preference for remaining close to the shore to the south of the Velvet Strand VP. At VP2, birds showed a strong preference for inshore areas between Ireland’s Eye and Velvet Strand (Figure A10.55, Appendix A10.1).

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Other Named Qualifying Species of the Ireland’s Eye Special Protection Area and Howth Head Coast Special Protection Area

Great black-backed gull is a Natura 2000 species of the Ireland’s Eye SPA. This species was present all year round, with a slight peak in numbers during the breeding season observed between May and July (Graph A10.2 and Table A10.10, Appendix A10.1). Great black-backed gulls on the water were evenly distributed across most of the sectors in the Ireland’s Eye VP viewing arc (Figure A10.58, Appendix A10.1). Birds on the sea between March and October were recorded more frequently loafing in distance bands further from the VPs (Table A10.18, Appendix A10.1). Of all birds on the sea recorded between March and October, 77.2% were either loafing or roosting.

Fulmar, a Natura 2000 species of the Ireland’s Eye and Howth Head Coast SPAs, were observed in relatively small and consistent numbers for much of the year (Graph A10.3, Appendix A10.1). The breeding season peak was 63 birds (Table A10.10, Appendix A10.1), and the winter peak was 159 birds (Table A10.6, Appendix A10.1). Except for the westernmost sectors of the Ireland’s Eye VP viewing arc, fulmar observations were quite evenly distributed (Figure A10.56, Appendix A10.1). Between March and October, most fulmars observed on the water (479 birds, or 89.8%) were recorded at VP2 on Ireland’s Eye (Table A10.19, Appendix A10.1). Of these observations, 470 birds (98.1%) were recorded either loafing, feeding or roosting. Shag is a Natura 2000 species of the Ireland’s Eye SPA. This species was recorded most frequently during the breeding season (Graph A10.4, Appendix A10.1), most frequently in May, June and July, with a single monthly peak of 129 birds (Table A10.10, Appendix A10.1). Of the 1,991 birds recorded on the water between March and October of all survey years, 1,301 (65.3%) were seen from VP2. Of these birds, 808 (62.1%) were feeding, most frequently between 0m and 1,000m from the VP (74.1% of feeding birds at VP2) (Table A10.20, Appendix A10.1). Feeding behaviour was also the most commonly encountered activity for this species from VP1 (623 birds, or 90.2% of the total number of birds recorded from VP1). From VP2, shags showed a preference for inshore waters between Ireland’s Eye and Velvet Strand (Figure A10.65, Appendix A10.1). Throughout the breeding season, the number of shags recorded was approximately double the number of cormorants recorded across the entire survey programme. The winter peak for shag was 47 birds (Table A10.6, Appendix A10.1).

Gannet is a Natura 2000 species of the Ireland’s Eye SPA. Just over 70% of all gannets recorded were observed during May, June and July (Graph A10.5, Appendix A10.1). The peak count of gannets in a single survey was 225 birds (Table A10.10, Appendix A10.1). Of 1,332 gannets recorded on the sea between March and October, 1,195 were observed from VP2 (89.7%) (Table A10.21, Appendix A10.1). Around two-thirds of these birds were recorded loafing or preening, and 409 (34.2%) were recorded plunge diving. Most of these records were located over 1,000m from the VP. Except for the westernmost sectors, gannet observations were quite evenly distributed throughout the viewing arc (Figure A10.57, Appendix A10.1). In winter, the peak count was 60 birds (Table A10.6, Appendix A10.1). Puffin is a species listed as a Natura 2000 species of the Ireland’s Eye SPA. Puffins were only recorded between March and July, with over 80% of records made in May to July (Graph A10.6, Appendix A10.1). The peak single VP survey count for puffin was 173 birds (Table A10.10, Appendix A10.1). Puffins were predominantly recorded within 500m of Ireland’s Eye (75.2% of records), and in smaller numbers between 500m and 1,000m away from Ireland’s Eye (Figure A10.63, Appendix A10.1). In total, 727 of 742 records on the water (97.9%) were recorded from VP2 (Table A10.22, Appendix A10.1). Of these birds, 700 were recorded loafing or preening (96.3%), and only 19 feeding.

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Black guillemot, a Natura 2000 species of the Ireland’s Eye SPA, was present throughout much of the year in low numbers (Graph A10.6, Appendix A10.1). Records were more numerous between March and July. The peak single monthly breeding season count was 14 (Table A10.10, Appendix A10.1), with the corresponding winter count being 22 (Table A10.6, Appendix A10.1). Black guillemots were most frequently recorded in the western count sectors of VP2 (Figure A10.54, Appendix A10.1). They were recorded in similar numbers from both VPs, favouring the more distant areas of the VP1 viewing arc from the VP, and areas of sea within 1,000m of the Ireland’s Eye VP (Table A10.23, Appendix A10.1). The most common behaviour recorded was feeding, accounting for 375 of 412 records (91.0%).

Although not a marine species, peregrine is a Natura 2000 species of the Ireland’s Eye and Howth Head Coast SPAs. Birds were observed in very low numbers though were present throughout the year (Graph A10.7, Appendix A10.1). The peak single monthly count was two during the breeding season (Table A10.10, Appendix A10.1), and four during the wintering period (Table A10.6, Appendix A10.1).

Other Bird Species Great-crested grebes were regularly recorded in the marine environment between October and April (Graph A10.8, Appendix A10.1). The peak single survey count was 255 birds (Table A10.7, Appendix A10.1). In general, numbers of this species recorded were much lower than the occasional peaks that were observed. Birds recorded from the VPs were located mainly within 1,500m of VP1 (1,574 of 1,901; 82.8%) (Table A10.24, Appendix A10.1). Of these, 910 birds (57.8%) were recorded either feeding or loafing between 500m and 1,000m from VP1.

Oystercatchers were present in fairly consistent numbers during the VP surveys all year round (Graph A10.8, Appendix A10.1), and the most frequently recorded species of the Baldoyle Bay SPA citation during VP surveys (Tables A10.7 and A10.11, Appendix A10.1). The peak single survey count was 210 birds during the winter (Table A10.7, Appendix A10.1), and 145 birds during the breeding season (Table A10.11, Appendix A10.1). Most commonly, birds were recorded within 500m of VP1 (Table A10.25, Appendix A10.1) and in distance band 4 (1,500m to 2,000m) from VP1. These birds were recorded in sectors A and F from VP1, meaning the vast majority of records were located in the intertidal area. Roosting on water was the most commonly recorded behaviour. Sanderlings were recorded in the marine environment between November and March (Graph A10.8, Appendix A10.1). All observations of this species were made from VP1. The peak single monthly count was 105 birds (Table A10.7, Appendix A10.1). In March (the only month between March and October that they were recorded), sanderlings were recorded most frequently within 500m of Velvet Strand. Observations made in distance band 4 occurred in sectors A and F, meaning they were located in the intertidal areas north and south of VP1 (Table A10.26, Appendix A10.1).

Dunlins were present in the marine environment throughout most of the year (Graph A10.9, Appendix A10.1), with the largest numbers recorded in December and January. Noteworthy numbers of observations were also made in June and July. The peak single survey count was 100 birds in winter (Table A10.7, Appendix A10.1), and 40 birds during the breeding season (Table A10.11, Appendix A10.1). Between March and October, dunlins were recorded feeding and roosting in distance bands 1 and 4 (sectors A and F) of VP1, albeit in fairly small numbers (Table A10.27, Appendix A10.1). Birds were not recorded from VP2. Red-breasted mergansers were present in the marine environment in low numbers throughout much of the year (Graph A10.9, Appendix A10.1). Peak numbers were recorded in March, with much lower numbers recorded between April and October. The peak single survey count was 90 birds (Table A10.7, Appendix A10.1), and 44

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birds during the breeding season (Table A10.11, Appendix A10.1). Of the 573 birds recorded between March and October during VP surveys, 560 were from VP1 (Table A10.28, Appendix A10.1). Birds were most frequently recorded feeding in distance band 2.

The temporal pattern of turnstone presence in the marine environment was relatively similar to dunlin and red- breasted merganser, but with lower overall abundance and a more obvious absence during most of the breeding season (Graph A10.9, Appendix A10.1). The peak single survey count was 44 birds during the winter (Table A10.7, Appendix A10.1), and 12 birds during the breeding season (Table A10.11, Appendix A10.1). All 59 observations of this species during VP surveys between March and October occurred in March, April and July. Of the observations, 88.1% were made from VP1 (Table A10.29, Appendix A10.1).

Small numbers of redshanks were recorded in March, April, June and October, as well as between December and April (Graph A10.10, Appendix A10.1). Numbers recorded were modest. The peak single monthly count was 36 birds during the winter (Table A10.7, Appendix A10.1), and 16 birds during the breeding season (Table A10.11, Appendix A10.1). Of the birds observed from VPs (all of which were from VP1), 87 were located in sector F. This means they were located in the intertidal area to the south of the VP (Table A10.30, Appendix A10.1).

The temporal pattern of ringed plover observation was unusual amongst the wading birds recorded in the marine environment (and was also noted in the estuarine surveys (Section 10.3.3)). Birds were recorded in the breeding and passage periods only. The peak single monthly count was 70 birds (Table A10.11, Appendix A10.1). Ringed plovers were recorded only from VP1, with 78 of the 136 total observations made within 500m of VP1 (Table A10.31, Appendix A10.1). Approximately double the number of birds were recorded roosting than feeding. Additional bird species listed in Table 10.6 can be grouped into three broad categories of temporal distribution in the area covered by the marine VP surveys:

 Species that were recorded in the wintering and breeding periods in the marine environment, in low or very low numbers, or predominantly in flight: light-bellied brent goose, curlew, bar-tailed godwit, black-tailed godwit, grey heron and shelduck;  Species that were recorded in the wintering period only in the marine environment, in low or very low numbers, or predominantly in flight: lapwing and mallard; and  Species that were not recorded in the marine environment: golden plover, grey plover, greenshank, knot, pintail and teal. Black-headed gulls were recorded throughout the year (Graph A10.11, Appendix A10.1) and were the most numerous non-SPA gull species recorded in the marine environment. The month in which the most gull records were made was October, whilst during the breeding season birds were present in relatively consistent numbers, with June having slightly more records than other months. The peak winter count was 223 (Table A10.8, Appendix A10.1), and 156 during the breeding season (Table A10.12, Appendix A10.1). In total, 2,516 black- headed gulls were recorded on the water between March and October, of which 2,340 (93.0%) were observed from VP1 (Table A10.32, Appendix A10.1). Of these, 2,035 (87.0%) birds were recorded loafing or roosting on water.

Common gulls were recorded all year round (Graph A10.11, Appendix A10.1), but in much lower numbers than black-headed gulls. Recorded numbers were slightly higher during the breeding season, with a peak count of 40 (Table A10.12, Appendix A10.1). In winter, the peak count was 23 (Table A10.8, Appendix A10.1). Between March and October, most records of birds on the water (77.1%) were made at VP1 (Table A10.33, Appendix

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A10.1). Roosting was the most frequently recorded behaviour, followed by loafing. The most commonly recorded behaviour from VP2 was loafing, with small numbers of birds recorded surface feeding between 1,000m and 2,000m from Ireland’s Eye.

Lesser black-backed gulls were present only in low numbers (Graph A10.11, Appendix A10.1). As with common gull, the breeding season saw the highest number of individuals recorded, with a peak of 14 (Table A10.12, Appendix A10.1). In winter, the peak was 25 (Table A10.8, Appendix A10.1). Spatial distribution of records on the sea between March and October was quite equal over the entire VP survey area, though numbers recorded from VP1 were greater (Table A10.34, Appendix A10.1). Overall numbers were low, and almost all birds were recorded roosting or loafing.

Red-throated divers were present throughout the winter and passage periods, being present between January and April and from September to December (Graph A10.12, Appendix A10.1). Between May and July, birds were absent, and were present in August and September in very low numbers. The peak survey count was 112 birds in March (Table A10.8, Appendix A10.1), and in April the peak had halved to 52 birds (Table A10.12, Appendix A10.1). Birds observed on the water were predominantly recorded from VP1: 599 of 739 birds (Table A10.35, Appendix A10.1). Most records were located in distance bands 2, 3 and 4 of VP1, with the most common behaviours feeding and loafing. Birds were also seen more frequently in distance bands 3 and 4 from VP2 in open water.

Great northern divers were recorded in small numbers (Graph A10.12, Appendix A10.1). They were recorded during most winter surveys, though the peak single survey count was just nine birds (Table A10.8, Appendix A10.1). Of the 10 birds recorded during March VP surveys, seven were recorded in distance band 1 of VP1, and three in distance band 4 of VP2 (Table A10.36, Appendix A10.1). This species was largely absent between April and October, with a single bird recorded in August. Common scoters were the most abundant non-SPA marine bird species during the winter months (Table A10.8, Appendix A10.1). During the breeding season, common scoters were completely absent in June and July, and present in low numbers during other months (Graph A10.13, Appendix A10.1). The peak winter count was 478 birds (Table A10.8, Appendix A10.1), and 128 during the breeding season (Table A10.12, Appendix A10.1). Of 6,061 common scoters recorded on the water during VP surveys between March and October, 4,129 (68.1%) were recorded loafing, whilst 1,892 birds (31.2%) were recorded feeding (Table A10.37, Appendix A10.1). Records were the most numerous in bands and sectors away from coastlines and in open water.

Several tern species were relatively abundant in the marine environment during the breeding season (Graph A10.14, Appendix A10.1). The most commonly occurring species was common tern. The peak count was 109 birds (Table A10.12, Appendix A10.1). Between March and October of all survey years, 125 birds were recorded on the water during VP surveys (Table A10.38, Appendix A10.1). Of these, 99 were observed from VP1 (79.2%). Birds were most frequently seen plunge diving in distance band 2. The next most abundant species was Sandwich tern, which was recorded between March and September. It was recorded on the water more frequently than the common tern, with 372 records between March and October in all survey years (Table A10.39, Appendix A10.1). The highest numbers were recorded in September (peak count of 58; Table A10.8, Appendix A10.1). Sandwich terns were evenly distributed throughout the viewing arcs of both VPs, though like common tern, the highest number of birds occurred in distance band 2 of VP1. Common terns were less likely to be observed within 500m of VPs compared with the rest of the VPs. The third most commonly recorded tern was not identified to

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species level and was either common or Arctic terns; based on numbers of positively identified birds, it is likely but unconfirmed that the majority of these birds would have been common terns.

Manx shearwaters were an abundantly recorded species during the breeding season (Graph A10.15, Appendix A10.1). Numbers recorded increased from April, with a peak in July/August. The peak count was 128 birds (Table A10.12, Appendix A10.1). Between March and October, 318 birds were recorded on the water (Table A10.40, Appendix A10.1). Of these, 264 birds were recorded in distance bands 3 and 4 of VP2 (83.0%). Roosting and surface feeding were the most commonly recorded behaviours. Additional bird species recorded during the marine VP surveys can be grouped into three broad categories of temporal distribution:

 Species that were recorded in the wintering and breeding periods in the marine environment, in low or very low numbers, or predominantly in flight: Arctic skua, blackbird, long-tailed duck, Mediterranean gull, ring- billed gull and whimbrel;  Species that were recorded in the wintering period only in the marine environment, in low or very low numbers, or predominantly in flight: black-necked grebe, black-throated diver, common or Arctic tern, goldcrest, little grebe, pink-footed goose, purple sandpiper, Slavonian grebe and swallow; and  Species that were recorded in the breeding period only in the marine environment, in low or very low numbers, or predominantly in flight: Arctic tern, eider, feral pigeon, great skua, greenfinch, kestrel, little stint, little tern, mute swan, roseate tern, sparrowhawk, storm petrel and tufted duck.

10.3.6 Ecological Value of Estuarine and Marine Birds Using the criteria in Table 10.1 and the information in Section 10.3, an ecological value has been assigned to each species encountered during the baseline estuarine and marine surveys. These are presented, sorted by ecological value. Only species that have been scoped into further assessment have been included.

Table 10.9: Ecological Value of Birds Recorded During Estuarine and Marine Ornithological Survey

Species Ecological Ecological Value Justification Value Bar-tailed godwit Very High SCI of Baldoyle Bay SPA, Fingal LBAP Black guillemot Very High Natura species of Ireland's Eye SPA, Fingal LBAP Black-tailed godwit Very High Natura species of Baldoyle Bay SPA, Fingal LBAP Brent goose Very High SCI of Baldoyle Bay SPA, population >1% international threshold, Fingal LBAP Common guillemot Very High SCI of Ireland's Eye SPA, Natura species of Howth Head Coast SPA, Fingal LBAP Cormorant Very High SCI of Ireland's Eye SPA, Fingal LBAP Curlew Very High Natura species of Baldoyle Bay SPA, Fingal LBAP Dunlin Very High Natura species of Baldoyle Bay SPA, Fingal LBAP Golden plover Very High SCI of Baldoyle Bay SPA, Fingal LBAP Great-crested grebe Very High Natura species of Baldoyle Bay SPA, Fingal LBAP Greenshank Very High Natura species of Baldoyle Bay SPA, Fingal LBAP Grey plover Very High SCI of Baldoyle Bay SPA, Fingal LBAP Great black-backed gull Very High Natura species of Ireland’s Eye SPA Herring gull Very High SCI of Ireland's Eye SPA, Natura species of Howth Head Coast SPA, Fingal LBAP Kittiwake Very High SCI of Ireland's Eye SPA and Howth Head Coast SPA, Fingal LBAP

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Species Ecological Ecological Value Justification Value Knot Very High Natura species of Baldoyle Bay SPA, Fingal LBAP Lapwing Very High Natura species of Baldoyle Bay SPA, Fingal LBAP Mallard Very High Natura species of Baldoyle Bay SPA Oystercatcher Very High Natura species of Baldoyle Bay SPA, Fingal LBAP Natura species of Howth Head Coast SPA, (also listed on Annex I of Birds Directive), Peregrine Very High Fingal LBAP Pintail Very High Natura species of Baldoyle Bay SPA, Fingal LBAP Puffin Very High Natura species of Ireland's Eye SPA Razorbill Very High SCI of Ireland's Eye SPA, Natura species of Howth Head Coast SPA, Fingal LBAP Red-breasted merganser Very High Natura species of Baldoyle Bay SPA, Fingal LBAP Redshank Very High Natura species of Baldoyle Bay SPA, Fingal LBAP Ringed plover Very High SCI of Baldoyle Bay SPA, Fingal LBAP Turnstone Very High Natura species of Baldoyle Bay SPA Sanderling Very High Natura species of Baldoyle Bay SPA Shag Very High Natura species of Ireland's Eye SPA, Fingal LBAP Shelduck Very High SCI of Baldoyle Bay SPA, Fingal LBAP Teal Very High Natura species of Baldoyle Bay SPA, Fingal LBAP Fulmar Very High Natura species of Ireland's Eye SPA and Howth Head Coast SPA Gannet Very High Natura species of Ireland's Eye SPA, Fingal LBAP Arctic tern High Listed on Annex I of Birds Directive, Fingal LBAP Black tern High Listed on Annex I of Birds Directive Black-headed gull High Listed on BoCCI Red List, 1% national threshold not available, Fingal LBAP Common gull High Listed on BoCCI Red List, 1% national threshold not available, Fingal LBAP Common scoter High Listed on BoCCI Red List, population >1% national threshold, Fingal LBAP Common tern High Listed on Annex I of Birds Directive, Fingal LBAP Great northern diver High Listed on Annex I of Birds Directive, Fingal LBAP Species that contribute to the integrity of Baldoyle Bay SPA but which are not cited as Grey heron High a species for which the site is designated Red-throated diver High Listed on Annex I of Birds Directive, Fingal LBAP Roseate tern High Listed on Annex I of Birds Directive, Fingal LBAP Ruff High Listed on Annex I of Birds Directive, Fingal LBAP Sandwich tern High Listed on Annex I of Birds Directive Great skua High Listed on BoCCI Amber List Lesser black-backed gull Medium Listed on BoCCI Amber List, 1% national threshold not available, Fingal LBAP Little egret Medium Listed on BoCCI Green List, Fingal LBAP Wigeon Medium Listed on BoCCI Red List, population <1% national threshold, Fingal LBAP Manx shearwater Medium Listed on BoCCI Amber List, population peaks high Mute swan Low Listed on BoCCI Amber List, population <1% national threshold Whimbrel Low Listed on BoCCI Green List

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10.4 Parameters for Assessment

10.4.1 Overview of the Proposed Project Works and Magnitude of Potential Impacts The construction of the proposed outfall pipeline route (marine section) will be undertaken using a combination of microtunnelling and subsea pipe laying techniques. The following sections provide an overview of the key parameters considered in this EIAR Chapter, which have been taken from the detailed project description provided in Chapter 4 Description of the Proposed Project. From this information, a magnitude of impact for each activity is assigned (Table 10.2), which is combined with the ecological value of receptors identified in the baseline (Table 10.1) to determine an impact significance (

Table 10.4).

10.4.2 Parameters Included in Assessment (Construction Phase) Disturbance/Displacement due to Land-Take of Proposed Microtunnelling Compounds

Two microtunnelling compounds will be constructed, which will be situated on the eastern (proposed temporary construction compound no. 10) and western (proposed temporary construction compound no. 9) sides of Baldoyle Bay (Figure 10.1 Location and Extent of Marine, Coastal and Estuarine Ornithological Surveys). Their construction will result in direct habitat loss, a negative ecological impact that will be limited to the compound footprint and access track. Effects would be temporary (24 hour working, 18 months duration). On completion of the construction works, proposed temporary construction compounds no. 9 and no. 10 will be dismantled and the ground will be reinstated to its original condition, meaning that land-take is a fully reversible impact.

Disturbance/Displacement due to Visual Impacts of Proposed Microtunnelling Compounds Within each microtunnelling compound, a range of construction activities will occur. These will be in direct line of sight to birds within the Baldoyle Bay SPA and surrounding habitats. This will be the case for the duration of the construction period, which is expected to be approximately 18 months. The extent of this effect is species- specific. Whilst the presence of a busy road within this area means that many birds in the area will be habituated to some activity, the presence of construction workers and vehicles could result in disturbance responses from birds that could be considered as relatively habituated to particular activities. Disturbance/Displacement due to Construction Noise (Piling) at Proposed Microtunnelling Compounds

Within each microtunnelling compound, a jacking shaft will be constructed using impact piling. This peak noise will be temporary, occurring for the initial setup phase during construction, which is estimated to be a maximum of two weeks duration, and impacts would be reversible. Piling noise would occur intermittently throughout this period and would be restricted to daytime, with peak noise falling into the >65dB to ≤75dB LAmax range. Noise experts have confirmed that noise levels resulting in substantial disturbance impacts to birds would result in minor impacts up to 90m from source. However, the presence of a busy road within this area means that any birds in the area will be habituated to relatively high noise levels to some degree.

Disturbance/Displacement due to Vessel Traffic in Proposed Subsea Section A negative ecological impact could occur through disturbance and/or displacement of birds due to the presence of vessels carrying out dredging, pipeline positioning and installation. The maximum adverse impact is expected to be localised around each vessel or group of vessels. These impacts will be temporary and reversible.

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The subsea section of the proposed outfall pipeline route (marine section) will involve the excavation of a trench approximately 4.9km long. Its westernmost point is the microtunnelling/subsea interface and it terminates at the proposed marine diffuser. Excavated material from trench preparation will be temporarily stored in barges within the proposed construction corridor. The proposed construction corridor for the subsea dredged section of the proposed outfall pipeline route (marine section) is estimated to be 250m wide. It is likely that a backhoe dredger will be used in shallower water and a trailer suction hopper dredger in deeper water. These operations would be supported by split bottom barges or similar, a survey vessel and a support vessel for crew transfer. It is possible that two groups of vessels could be working on the subsea section at any one time. The spread of the sediment plume created by this activity will involve the controlled release of spoil material by hopper barge every seven hours (refer to Chapter 9 Biodiversity (Marine). This will produce a northerly plume drifting away from Ireland’s Eye. The highest concentrations of suspended sediments (>10g/l) were recorded at bed level within 50m to 100m of the discharge point. The granular nature of these sediments results in a fast settlement of material to the bottom, with seabed and mid-depth concentrations generally falling to below 1g/l within 200m from the discharge. The subsea section of the proposed outfall pipeline route (marine section) will be installed using a ‘float and sink’ method. The pipes are manufactured and welded at the factory into long lengths and towed to site. Pipeline stringing assembly and ballasting activities will be carried out at a location in Dublin Port or at adjacent river berths of the Liffey River.

Marine construction is expected to take approximately three months in total, with dredging occurring for 12 hours per day and pipe assembly occurring at the same time (refer to Chapter 8 Marine Water Quality). Construction of this section of the Proposed Project will occur between March and October. The exact timing of the works will depend on the availability of a suitable weather window.

The subsea section does not include the proposed marine diffuser, which is described below. Disturbance/Displacement due to Vessel Traffic and Construction Noise at Proposed Marine Diffuser

The construction of a marine diffuser is required to make the hydraulic connection between the proposed outfall pipeline route (marine section) and the seabed and is necessary to discharge the treated wastewater from the proposed outfall pipeline route (marine section) at the discharge point. A negative ecological impact could occur through the presence of a number of vessels, leading to disturbance and displacement of birds.

The proposed marine diffuser will be installed by use of the concrete ballasts. Once the pipeline is sunk, a team of divers will install the diffuser valves. It has been assumed that dredging and construction occurring at the closest point to the Ireland’s Eye SPA (i.e. at the proposed marine diffuser) is likely to occur for a maximum of three weeks.

Indirect Impacts on Baldoyle Bay

Chapter 9 Biodiversity (Marine) discusses the impact of a sediment plume from the dredging of the subsea dredged section of the proposed outfall pipeline route (marine section). It is concluded that impacts associated with the plume will be temporary and highly localised and will not reach Baldoyle Bay. The impact significance is therefore Negligible. The area of the proposed outfall pipeline route (marine section) is considered a low intensity spawning and nursery ground for sandeel, which is a common prey species of a number of seabirds present in the wider area. Sandeel populations in the immediate vicinity of the subsea dredged section of the proposed outfall pipeline route (marine section) would be affected by habitat loss and disturbance through sediment excavation and deposition during dredging and trenching activities. This could result in a negative ecological

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impact to populations in the area to be dredged, and the immediate surrounding habitat out to approximately 50m to 100m from each discharge point.

10.4.3 Parameters Excluded from Assessment (Construction Phase) Disturbance/Displacement due to General Noise, Construction Activity and Vehicle Traffic at Proposed Microtunnelling Compounds The baseline environment around Baldoyle Bay contains numerous sources of potential disturbance stimuli for birds. The Baldoyle Bay Estuary lies on the approach to Dublin Airport’s main runway. Observations made during ornithological surveys revealed that aircraft overfly the northern section of Baldoyle Bay very frequently. The R106 Coast Road, running down the western side of the bay, passes between the SPA boundary and the proposed temporary construction compound no. 9 for microtunnelling. A cycle path runs parallel to the road.

The Baldoyle residential area to the south-west of Baldoyle Bay, and the Portmarnock and Sutton Golf Clubs on the eastern and south-eastern sides of the bay are other sources of disturbance. Velvet Strand Beach to the east is also frequented by a range of recreational users.

In general, this suggests that many of the birds using the Baldoyle Bay SPA and surrounding area are habituated, to a degree, to a range of general visual and/or noise stimuli, including the presence of vehicles. In consultation with published advice on the typical types and magnitudes of visual and noise sources associated with construction activities (Cutts et al. 2013), it is considered that general construction activities, the presence of a crane and the presence of vehicle traffic associated with the microtunnelling compounds will result in a Negligible impact significance to all bird species.

For the construction or operation of the Proposed Project to result in disturbance to the birds in the area, the noise/visual stimuli would have to substantially exceed those that are already present in some way. For this reason, piling noise during the construction of jacking shafts in the microtunnelling compounds is considered in the assessment. General Pollution Incidents Upstream

Regarding water quality and habitat deterioration, the mechanism by which impacts on estuarine and coastal waters could occur during construction is pollution incidents and elevated suspended sediments occurring upstream of Baldoyle Bay. It has been predicted that any impacts caused by upstream pollution incidents represent a negligible level of impact on the Baldoyle Bay, and consequently also on coastal waters.

Pollution Caused by Air or Bentonite Breakout During Microtunnelling

Chapter 9 Biodiversity (Marine) discusses the possibility of air or bentonite breakout during microtunnelling.

The depth of the microtunnelling route beneath the estuary means that the likelihood of a bentonite breakout making it to the surface of the estuary is very low; however, the result of a breakdown may result in a small discharge to the surface. If this occurs in the channel or open water environments, then this material will disperse harmlessly. If this occurs within the saltmarsh vegetation, then this material is unlikely to disperse quickly due to the lack of tidal flow in these areas, and may require some intervention to recover and disperse to avoid a smothering effect.

The impacts of increased turbidity are likely to be minimal in the overall context of Baldoyle Bay, as the water depth is extremely shallow and the natural suspended sediment very fine. Bentonite is naturally occurring and

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non-toxic to marine benthic fauna. In the unlikely event of a bentonite breakout, a small quantity of this suspended clay escaping into the watercourse may produce a localised plume of limited size and duration which may induce some avoidance behaviour by some non-qualifying species (i.e. fish and seals) within the area. Because it is not considered that birds would be affected by the worst case scenario, it is considered to be of Negligible impact significance to all bird species.

Use of Tunnel Boring Machine During Microtunnelling

Chapter 9 Biodiversity (Marine) considers that the noise generated during microtunnelling is of negligible impact magnitude on fish, pinnipeds and harbour porpoise. This is because the predicted levels of noise in the sediments and water column are far below a minimum action level of where this vibration can be perceived by passing fauna. On this basis, it is considered that the impacts from microtunnelling will be Negligible and therefore not significant for birds.

Disturbance/Displacement due to Construction (Piling) at Microtunnelling/Subsea Interface and Fibre Optic Cable Crossing The microtunnelled section of the proposed outfall pipeline route (marine section) will terminate approximately 1km north-east of Ireland’s Eye.

The Tunnel Boring Machine used during microtunnelling will terminate into a temporary cofferdam (or pre-dredged reception pit). As the microtunnelled section is being progressed, cofferdam construction will commence with the aid of a jack-up platform and associated support vessels. The cofferdam construction will use a sheet piling methodology. Installation could utilise vibratory hammers, impact hammers or a hydraulic method. It is estimated that this piling could result in temporary disturbance and displacement of birds up to 90m from source, for a time period of up to two weeks, with peak noise falling into the >65dB to ≤75dB LAmax range. Vessels will be present for approximately three months in total, of which a maximum of two weeks would overlap with dredging of the subsea section of the proposed outfall pipeline route (marine section).

The proposed outfall pipeline route (marine section) traverses a subsea fibre optic cable. This is located approximately 2.5km from the microtunnelling/subsea interface, and 0.9km from Ireland’s Eye. Interlocking sheet piles will be driven to support the pipeline trench near the fibre optic cable. It is estimated that this piling could result in temporary disturbance and displacement of birds up to 90m from source, with peak noise falling into the

>65dB to ≤75dB LAmax range for a time period of up to two weeks. It is likely that vessels would be present at this location for a period of one month, and that vessels would be present at one location at once.

The 90m disturbance distance is considered to result in a negligible impact and is therefore considered not significant. The presence of vessels without this noise is considered to be of Negligible impact significance.

10.4.4 Parameters Included in Assessment (Operational Phase) It is considered that there are no parameters associated with the operation of the Proposed Project that need to be included in the assessment.

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10.4.5 Parameters Excluded from Assessment (Operational Phase) Maintenance Activities The normal operation of the Proposed Project and its constituent elements will be fully automated, which will be monitored, controlled and managed from a control centre located at the proposed WwTP.

The automated control systems will report through supervisory control and data acquisition (SCADA) and telemetry systems to the control centre. The proposed WwTP and SHC will be manned 24 hours a day, seven days a week. It is envisaged that between 30 and 40 operations staff will be employed, working in normal shift patterns, to ensure the continued and efficient operation of all elements of the Proposed Project. Maintenance activities would typically include the following:

 General maintenance (daily);  Preventative maintenance (as scheduled by operator);  Proposed Abbottstown pumping station inspections (weekly visit);  Inspection chambers on pipelines (annual visit); and  Inspection of multiport diffusers (annual dive survey). The existing sources of disturbance in and around Baldoyle Bay and the subtidal habitats around Ireland’s Eye mean that birds are habituated to a range of human activity. Therefore, any impacts arising from maintenance activities will not add to or be greater than any impacts already experienced by the birds.

Pollution

During operation, the operational plume could also result in impacts to estuarine and coastal waters. Results of the effluent discharge qualities modelled during the Operational Phase indicate that the plume created by the effluent discharge will be subject to significant dispersion, with a 20-fold dilution obtained within 50m of the diffuser and between 33- and 100-fold dilution within 500m of the diffuser (see Chapter 9 Biodiversity (Marine)). As Baldoyle Bay is located approximately 5km from the marine diffuser, the effluent plume will therefore not affect prey species within estuarine waters. The level of dilution means that the impact on coastal waters will be of Negligible significance to estuarine and marine birds. Plankton

Modelling shows that the discharge from the proposed marine diffuser will disperse and dissipate over a large area (see Chapter 9 Biodiversity (Marine)). The presence of organically enriched waters, through slightly elevated levels of dissolved inorganic nitrogen, may enhance plankton productivity over the larger area which itself may encourage feeding from prey species in the vicinity, but the impact of this is expected to be of Negligible significance with respect to estuarine and marine birds.

10.5 Potential Impacts on Ornithological Receptors

10.5.1 Disturbance and/or Displacement Disturbance often implies a short-term or temporary impact that is unlikely to affect the individuals or populations of birds concerned. However, it is a term that covers a wide range of responses in birds. Disturbance is defined

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here as any situation in which human activities cause a bird to behave differently from the behaviour it would be reasonably expected to exhibit without the presence of that activity.

In this Chapter, disturbance to birds is predicted to occur due to a number of activities. This includes piling noise during microtunnelling compound construction, microtunnelling/subsea interface construction and fibre optic cable crossing construction. Disturbance by vessels in the marine environment (dredged section of the proposed outfall pipeline route (marine section) and marine diffuser) is also predicted. These activities will result in evasive action being taken by birds. In the estuarine environment, disturbance can manifest in a number of forms of varying severity depending on the nature, duration and intensity of the disturbance source:

 Birds looking up or heads raised, temporarily stopping feeding or roosting;  Birds moving away from the cause of the disturbance by walking or swimming before resuming previous activity;  Birds taking flight and landing somewhere in the same feeding area or mudflat; and  Birds taking flight and leaving the survey area completely. The resulting impacts of disturbance episodes for estuarine birds are variable. In general, each subsequent level of severity will result in a greater reduction in feeding time, and greater energy expenditure. Flushing (moving away in response to disturbance) is an energetically expensive activity that can result in decreases in the overall fitness of a population, which in turn can lead to reduced breeding success and increased mortality. Birds that are more tolerant than other individuals and remain in an area affected by disturbance may not forage efficiently, and if there are additional pressures on the birds (for example cold weather), then this may impact upon the survival of individual birds or their ability to breed later in the year. The term ‘habituated’ is used to describe birds that have become accustomed to particular sources of disturbance.

For birds on the sea, behavioural responses to the presence of vessels also involve flushing, either into flight or by diving in the case of species such as divers and auks. This reduces feeding time and increases energy expenditure, with knock on impacts to breeding success and mortality possible.

At seabird colonies such as Ireland’s Eye, a range of disturbance responses is possible. This can be a moderate response such as a heads up or walking behaviour. The most extreme response is flushing. Flushing during incubation or chick-rearing periods can lead to egg or chick loss because of displacement from the breeding site, egg breakage or predation. The effects of flushing on birds that are not attending eggs or chicks include disruption of courtship, nest-site defence and prospecting activities.

Displacement, incorporating disturbance, is considered the Construction Phase only. The Operational Phase has been scoped out of further assessment. This is because it is considered that maintenance vessel traffic once a year is the only potential source of disturbance, and that the Proposed Project infrastructure does not possess the potential to cause a bird to behave differently from the behaviour it would be reasonably expected to exhibit without the presence of the Proposed project infrastructure.

A range of literature has been consulted to assist with the prediction of species-specific responses for the estuarine and marine environment. The approach to assessment makes use of previous indications of behaviour detailed in the literature above and the value/sensitivity of the population in question.

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10.5.2 Indirect Impacts Indirect impacts may occur through changes in abundance and distribution of prey. This is interpreted in terms of the species’ flexibility in habitat use (Garthe and Hüppop 2004; Furness and Wade 2012), and the spatial and temporal extent of the potential change during construction.

10.6 Assessment of Significance

10.6.1 Construction Phase A description of the potential changes on ornithological receptors caused by each identified impact is given below. In general, the impacts arising from the construction of the Proposed Project are temporary and reversible, as they only occur during the Construction Phase.

Due to weather constraints, the subsea pipeline, microtunnelling/subsea interface, fibre optic cable crossing and marine diffuser will only be constructed between March and October.

Whilst the proposed microtunnelling compounds (proposed temporary construction compounds no. 9 and no. 10) can be constructed at any time of year, the hoarding surrounding them can only be installed between April and August unless supervised by an ecologist. This also applies to its removal, which can only occur once all construction activities at the compounds have been completed.

Other embedded mitigation measures will be the presence of an Ecological Clerk of Works at the proposed microtunnelling compounds (proposed temporary construction compounds no. 9 and no. 10) and the production of a Construction Environmental Management Plan to ensure best practice measures are implemented.

Disturbance/Displacement due to Direct Land-Take of Proposed Microtunnelling Compounds The species that will be affected by direct land-take are those that have been recorded within the footprints of the proposed microtunnelling compounds (proposed temporary construction compounds no. 9 and no. 10) during the ornithological surveys. However, it is accepted that other species of the Baldoyle Bay SPA, or non-designated species that were not recorded locally, may, from time to time, occur on the land. Table 10.10 presents bird records that were made within the footprint of proposed temporary construction compound no. 9 to the west of Baldoyle Bay. Table 10.11 presents the same data for the footprint of proposed temporary construction compound no. 10, to the east. Birds recorded in flight within the footprint of both compounds are excluded from these tables, as they were not considered to be utilising the habitat, only the airspace.

Table 10.10: Birds Recorded Within Footprint of Proposed Temporary Construction Compound No. 9 (West of Baldoyle Bay)

Species Number of Birds Survey Date Behaviour

Curlew* 27 13/04/2015 Roosting/Loafing

Curlew* 6 30/06/2015 Roosting/Loafing

Herring gull** 2 12/10/2017 Roosting/Loafing Notes *Named non-SCI species of Baldoyle Bay SPA **SCI species of Ireland’s Eye SPA

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Table 10.11: Birds Recorded Within Footprint of Proposed Temporary Construction Compound No. 10 (East of Baldoyle Bay)

Species Number of Birds Survey Date Behaviour

Black-headed gull 1 11/03/2015 Roosting/Loafing

Ringed plover* 1 13/04/2015 Roosting/Loafing

Herring gull*** 3 27/05/2015 Scavenging

Black-headed gull 5 05/06/2015 Scavenging

Herring gull*** 2 05/06/2015 Scavenging

Black-headed gull 4 30/06/2015 Scavenging

Herring gull*** 5 15/07/2015 Scavenging

Lesser black-backed gull 1 15/07/2015 Scavenging

Black-headed gull 3 22/09/2015 Scavenging

Black-headed gull 2 07/01/2016 Scavenging

Black-headed gull 8 16/03/2016 Scavenging

Black-headed gull 4 01/04/2016 Scavenging

Black-headed gull 2 22/05/2016 Scavenging

Black-headed gull 2 26/04/2017 Scavenging

Herring gull*** 3 26/04/2017 Scavenging

Lesser black-backed gull 2 17/05/2017 Scavenging

Black-headed gull 13 12/09/2017 Scavenging

Black-headed gull 3 12/10/2017 Scavenging

Black-headed gull 6 20/11/2017 Scavenging

Black-headed gull 6 11/12/2017 Scavenging

Black-headed gull 8 11/01/2018 Scavenging

Herring gull*** 2 11/01/2018 Scavenging

Oystercatcher** 6 11/01/2018 Feeding Notes *SCI species of Baldoyle Bay SPA **Named non-SCI species of Baldoyle Bay SPA ***SCI bird species of Ireland’s Eye SPA

In 64 survey visits, a single record of two herring gulls and two records of groups of curlew were recorded using the habitat within the footprint of the proposed western microtunnelling compound. The former is an SCI of the Ireland’s Eye SPA, and the latter is a named species of the Baldoyle Bay SPA. All birds recorded were roosting and loafing. In the same number of survey visits, observations of SPA-qualifying species utilising the site of the proposed eastern microtunnelling compound were limited to a single record of a roosting ringed plover (SCI of Baldoyle Bay SPA), a single record of feeding oystercatcher (named species of Baldoyle Bay SPA), and several records of scavenging herring gull (SCI of Ireland’s Eye SPA). Black-headed gull were the most frequently recorded species, and lesser black-backed gull was also occasionally recorded. Gull species were recorded scavenging from the bins in the car park.

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Although small numbers of birds occasionally utilise the area for roosting, loafing, scavenging or feeding, the relatively low frequency of observations and the low numbers of birds present suggests that the habitat in the footprint of the microtunnelling compounds is not critical for any bird species present in the local area. Based on the character of the land in its current state, it is considered that there is alternative habitat nearby for these species to conduct the behaviour recorded within the proposed microtunnelling compounds (proposed temporary construction compounds no. 9 and no. 10). Following the start of construction, any birds that may be using the land in question (which it should be noted is outside the Baldoyle Bay SPA boundary) will simply relocate and would not be lost to the population as a result of construction of the microtunnelling compounds.

The magnitude of impact of land-take of proposed temporary construction compounds no. 9 and no. 10 is considered to be negligible. This results in a Minor impact significance for any species of very high ecological value associated with the proposed microtunnelling compound sites (i.e. SCIs and Natura 2000 species of the Baldoyle Bay SPA and Ireland’s Eye SPA) and a Negligible impact significance for all other species. This prediction is of near-certain confidence. There is no requirement for additional mitigation measures. Disturbance/Displacement due to Visual Impacts at Proposed Microtunnelling Compounds

Visual disturbance resulting from the construction and presence of the microtunnelling compounds along with the activities associated with them could result in impacts within the Baldoyle Bay SPA and habitats outside the boundary. This is a reversible impact that would occur for the duration of the construction period. A generic visual disturbance distance of 300m recommended by Cutts et al. (2013) applies to other wading birds using the area.

This level of disturbance applies to work during daylight and darkness. Working at night would require artificial lighting, which has been shown to benefit estuarine birds by increasing foraging opportunity (Santos et al. 2010).

In habitats within 300m of proposed temporary construction compound no.9, 11,694 birds were recorded during the estuarine surveys. Of these, 2,843 records were SCI species of the Baldoyle Bay SPA (850 golden plover, 653 grey plover, 651 shelduck, 428 light-bellied brent geese, 207 bar-tailed godwit and 54 ringed plover). A further 6,703 records were named qualifying species of the Baldoyle Bay SPA. There were also 479 records of SCI species from the Ireland’s Eye SPA (herring gull, guillemot and razorbill). In habitats within 300m of proposed temporary construction compound no. 10, 5,350 birds were recorded during the estuarine surveys. Of these, 2,707 records were SCI species of the Baldoyle Bay SPA (1,800 golden plover, 512 light-bellied brent geese, 203 shelduck, 169 ringed plover, 20 grey plover and three bar-tailed godwit). A further 1,683 records were named qualifying species of the Baldoyle Bay SPA, and 207 records were birds named on the Ireland’s Eye SPA citation.

The areas that could potentially be impacted by the visual disturbance impact pathway are large, and are frequently used by large numbers of SCIs of the Baldoyle Bay SPA, along with other named species of the SPA, and other waders and waterbirds. Whilst many birds will habituate to this activity over time, the size of these areas and the number of birds that could be disturbed and displaced could create knock on effects relating to competition and habitat availability, and could result in many birds being lost from the population.

The magnitude of impact of visual disturbance will be medium due to the relatively large spatial (between 50m and 500m from each compound, depending on the species in question) and temporal (duration of construction activities at microtunnelling compounds) extent of activities at the microtunnelling compounds. This results in a Major impact significance for any species of very high ecological value associated with these small areas of habitat (i.e. SCIs and Natura 2000 species of the Baldoyle Bay SPA and Ireland’s Eye SPA) and a Moderate or

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Minor impact significance for other species. This prediction is of near-certain confidence. Mitigation is required to reduce the impact significance for these species throughout the construction period, and is detailed in Section 10.9.

Disturbance/Displacement due to Construction Noise (Piling) at Proposed Microtunnelling Compounds The species that will be affected by piling noise are those that have been recorded within the specified distance of the piling source during the ornithological surveys. This distance has been defined by noise experts to be approximately 90m based on the estimated maximum sound level anticipated during the piling (dB LAmax). Error! R eference source not found.Figure 10.2 Bird Distribution within 90m of Proposed Temporary Construction Compound No. 9 (December 2014 to March 2018) and Figure 10.3 Bird Distribution within 90m of Proposed Temporary Construction Compound No. 10 (December 2014 to March 2018) illustrate the distribution of bird records relative to these areas for the western and eastern microtunnelling compounds respectively, along with the corresponding buffers. Piling will occur at least 50m from the Baldoyle Bay SPA boundary on the western side of the estuary, and at least 140m from the SPA boundary on the eastern side of the estuary. Table 10.12, Table 10.13 and Table 10.14 present the number and frequency of species records that have been scoped into the assessment within this distance of proposed temporary construction compounds no. 9 and no. 10, to the west and east of Baldoyle Bay, respectively. Birds recorded in flight within the footprint of both compounds are excluded from these tables, as they were not considered to be utilising the habitat, only the airspace.

Table 10.12: Birds Recorded Within 90m of Piling Location of Proposed Temporary Construction Compound No. 9 to the West of Baldoyle Bay and Inside Baldoyle Bay Special Protection Area

Species Number of Birds Frequency of Observation Key Behaviour

Lapwing** 123 10 Roosting, loafing, non-continuous flight, feeding

Wigeon 83 6 Feeding, roosting, loafing

Redshank** 64 6 Loafing, roosting, feeding

Teal** 61 5 Roosting, feeding, loafing

Oystercatcher** 50 2 Loafing

Dunlin** 37 1 Roosting, loafing

Mallard** 34 7 Feeding, roosting, loafing

Snipe 12 5 Roosting, loafing

Curlew** 7 2 Loafing, feeding

Grey heron** 7 7 Feeding

Little egret 7 7 Loafing, feeding

Black-headed gull 6 1 Feeding

Herring gull*** 1 1 Non-continuous flight

Pintail** 1 1 Loafing

Mute swan 1 1 Feeding

Greenshank** 1 1 Roosting/loafing

Shelduck* 1 1 Feeding

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Species Number of Birds Frequency of Observation Key Behaviour Notes *SCI species of Baldoyle Bay SPA **Named non-SCI species of Baldoyle Bay SPA ***SCI bird species of Ireland’s Eye SPA

Table 10.13: Birds Recorded Within 90m of Piling Location of Proposed Temporary Construction Compound No. 9 to the West of Baldoyle Bay and Outside Baldoyle Bay Special Protection Area

Species Number of Birds Frequency of Observation Key Behaviour

Lapwing* 13 9 Non-continuous flight, roosting/loafing, feeding

Black-headed gull 11 1 Roosting/loafing

Herring gull** 2 1 Roosting/loafing

Buzzard 1 1 Non-continuous flight Notes *Named non-SCI species of Baldoyle Bay SPA **SCI bird species of Ireland’s Eye SPA

Table 10.14: Birds Recorded Within 90m of Piling Location of Proposed Temporary Construction Compound No. 10 to the East of Baldoyle Bay

Species Number of Birds Frequency of Observation Key Behaviour

Black-headed gull 129 23 Non-continuous flight, scavenging, loafing

Little grebe 40 32 Loafing, feeding

Mallard** 38 29 Feeding, loafing

Moorhen 37 29 Loafing, feeding

Herring gull*** 25 9 Scavenging

Ringed plover* 23 4 Feeding, loafing

Oystercatcher** 22 8 Feeding

Light-bellied brent goose* 6 1 Feeding

Curlew** 5 2 Non-continuous flight, feeding

Grey heron** 3 3 Feeding

Lesser black-backed gull 3 2 Scavenging

Coot 2 2 Feeding, loafing

Common snipe 1 1 Non-continouos flight Notes *SCI species of Baldoyle Bay SPA **Named non-SCI species of Baldoyle Bay SPA ***SCI bird species of Ireland’s Eye SPA

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Of the 64 survey visits, lapwing was observed in nine of them to be within 90m of the site of proposed temporary construction compound no. 9, outside the Baldoyle Bay SPA. Three other species were observed in this area on a single occasion: herring gull (an SCI of Ireland’s Eye SPA), black-headed gull and buzzard. Within 90m and within the Baldoyle Bay SPA, a range of species were recorded. The SCI shelduck was recorded very infrequently. The most numerous and regularly recorded named SPA species in this area was lapwing, followed by redshank, teal and oystercatcher. Despite this, no species was recorded on more than 10 survey visits (16% total visits), with most being recorded more infrequently than this. The 90m buffer around the piling areas within the footprint of proposed temporary construction compound no. 10 was populated with low numbers of Baldoyle Bay SPA SCIs, in this case ringed plover and light-bellied brent goose. Ringed plover were recorded on just over a third of visits in this area, in each case a single group consisting of between three and nine birds. Light-bellied brent goose was recorded once in this area during the survey programme. Other named SPA species regularly present in this area were mallard and oystercatcher, with curlew and grey heron present occasionally. Herring gull, an SCI of Ireland’s Eye SPA, was occasionally present scavenging in this area. Other non-designated species regularly present were black-headed gull, little grebe and moorhen.

Although small numbers of birds occasionally utilise these areas, the low numbers and frequency of observations suggests that these habitats are not critical for any bird species present in the local area. Based on the character of the land in its current state, it is considered that there is alternative habitat nearby for these species to conduct the behaviour recorded within these habitats. Following the start of construction, any birds that may be using the land in question will simply relocate and would not be lost to the population as a result of construction of proposed temporary construction compounds no. 9 and no. 10.

The magnitude of impact of piling will be negligible due to the small spatial (90m from source of piling noise) and temporal (two weeks) extent of piling activities, coupled with the fact that pre-existing noise sources in the area mean that only birds that are habituated to noise use the area. This results in a Minor impact significance for any species of very high ecological value associated with these small areas of habitat (i.e. SCIs and Natura 2000 species of the Baldoyle Bay SPA and Ireland’s Eye SPA), and Negligible impact significance for all other species. This prediction is of near-certain confidence. There is no requirement for additional mitigation measures.

The LAP ‘quiet zone’ is considered to be of low ecological value because of the very low numbers of birds recorded there between 2014 and 2018. The impact on the LAP zoned land as a result of piling will be low due to the small spatial (90m from source) and temporal (two weeks) extent of piling activities, resulting in a Negligible impact significance. Disturbance/Displacement due to Vessel Traffic in Proposed Outfall Pipeline Route (Marine Section)

To assess the potential impacts of vessel disturbance and displacement on individual species in the dredged section of the proposed outfall pipeline route (marine section), an appreciation of their relative sensitivity to vessel traffic is required, in addition to understanding the nature of the works across the subtidal section and which elements will occur concurrently or in sequence (Section 10.4).

Of the very high ecological value species associated with the Ireland’s Eye SPA and Howth Head Coast SPA, herring gull, kittiwake, fulmar, great black-backed gull and gannet are all highly mobile species that spend a significant amount of time in flight (Garthe and Hüppop 2004; Furness and Wade, 2012) and have large foraging ranges (Thaxter et al. 2012). Vessel traffic is considered to have a negligible impact magnitude on these species

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resulting in a Minor impact significance. This can be reduced to Negligible due to the very low vulnerability of these species to boat traffic according to published literature (Garthe and Hüppop 2004; Furness and Wade 2012) and professional judgement. The same impact significance applies to peregrine, because this species does not use the sea in a way that is likely to render it sensitive to disturbance by vessel traffic. Guillemot, razorbill and black guillemot are species of medium vulnerability to vessel traffic (Garthe and Hüppop 2004; Furness and Wade 2012). These species may illicit a degree of disturbance by vessel activity either by flushing from the sea surface or diving when a vessel approaches. Auk species have been shown to exhibit flushing behaviour of up to 600m (Bellefleur et al. 2009; Ronconi and Clair 2002), although these studies involved vessels travelling at relatively high speed. It is expected that this distance will be less for the Proposed Project, as it will involve vessels that are either stationary or travelling at low speed. During July and August, auks leave the Ireland’s Eye area with their chicks to moult offshore. During the process of leaving, some birds may be flightless (Wright and Begg 1987) and more susceptible to disturbance. These birds are unlikely to occur in the dredged section of the proposed outfall pipeline route (marine section), and were not recorded in this location during the targeted surveys in 2016 and 2017, but their presence is conceivable during July and August.

Guillemot and razorbill were the most frequently recorded birds on the sea during the time of the year where vessels are likely to be active in the dredged section of the proposed outfall pipeline route (marine section). However, it is clear from the distribution of these species that the majority of the dredged section of the proposed outfall pipeline route (marine section) is of limited importance to them, and that the majority of these very high ecological value populations do not occur within the dredged section of the proposed outfall pipeline route (marine section), though they are present in the proposed construction corridor in lower numbers. Black guillemots were recorded in much lower numbers, with 232 of 412 birds (56.3%) recorded within 1km of Ireland’s Eye. Within the dredged section of the proposed outfall pipeline route (marine section), guillemots, razorbills and black guillemots were recorded feeding and loafing. The sensitivity of the guillemot, razorbill and black guillemot population that is present within the dredged section of the proposed outfall pipeline route (marine section) is considered to be high. Some birds will be disturbed and displaced due to vessels operating within the dredged section of the proposed outfall pipeline route (marine section). Compared to the rest of the proposed outfall pipeline route (marine section), disturbance is particularly likely in the 1,300m of the proposed construction corridor prior to its termination at the marine diffuser, as this is the closest part of the diffuser to the Ireland’s Eye SPA. Due to the relatively small area affected at any given time, with a maximum of three groups of vessels operating within the proposed outfall pipeline route (marine section), the temporary and reversible nature of the impact, and the high availability of alternative habitat in the area, this impact has been assigned a low impact magnitude. For guillemot, razorbill and black guillemot (high ecological sensitivity), a Minor impact significance as a result of disturbance and displacement by vessel traffic in the proposed outfall pipeline route (marine section) is predicted. For guillemot and razorbill in July and August, a very high ecological sensitivity has been assigned along with a low impact magnitude, resulting in a Moderate impact significance. Mitigation is required to reduce the impact significance for this species group during this time period.

Puffin are of below average sensitivity to vessel traffic (Garthe and Hüppop 2004; Furness and Wade 2012). Of the 742 records of birds on the water, 705 (95%) were recorded within 1km of Ireland’s Eye, meaning that the majority of the dredged section of the proposed outfall pipeline route (marine section) is of very limited importance to this species. Activities in the dredged section of the proposed outfall pipeline route (marine section) resulting in disturbance to this species are more likely in the final 1,300m before the marine diffuser, as this is the closest section of the proposed construction corridor to the Ireland’s Eye SPA. The sensitivity of puffins within the

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dredged section of the proposed outfall pipeline route (marine section) is considered to be low. Due to the relatively small area affected at any given time, the temporary and reversible nature of the impact, and the high availability of alternative habitat in the area, this impact has been assigned a low impact magnitude. The impact significance of vessel traffic in the dredged section of the proposed outfall pipeline route (marine section) for puffin is therefore Negligible.

Both cormorant and shag are of above average sensitivity to vessel traffic (Garthe and Hüppop 2004; Furness and Wade 2012). Despite this, evidence from Burbo Bank (CMACS 2008) and Robin Rigg (E.ON/Natural Power 2012) offshore wind farms has shown that densities of cormorant increased during their construction phases. Both cormorant and shag are relatively flexible with respect to habitat use (Garthe and Hüppop 2004; Furness and Wade 2012). Both species were regularly recorded on the sea in the dredged section of the proposed outfall pipeline route (marine section) throughout the period where vessels associated with the Proposed Project would be expected to be present. Cormorants were recorded in greater numbers in nearshore locations. As both species are capable of utilising areas of sea that will be beyond the zone of influence (ZoI) of vessel disturbance, and because of the relatively small area affected at one time, the temporary and reversible nature of the impact, and the high availability of alternative habitat in the area, the impact of disturbance through vessel activity is predicted to be negligible. Combined with the very high ecological value, this results in a Minor impact significance for these species.

None of the SCIs and all but three Natura 2000 species of the Baldoyle Bay SPA were present in sufficient numbers, or sufficiently frequently in the marine environment at the appropriate time of year, for vessel disturbance to be considered an issue (Negligible impact significance). The three species that were exceptions (oystercatcher, ringed plover and red-breasted merganser) have been investigated further. The vast majority of records of all species were made within 1km of Velvet Strand, largely outside the dredged section of the proposed outfall pipeline route (marine section) and the ZoI for vessel disturbance. These species were associated primarily with the intertidal area of Velvet Strand and the shallow nearshore waters. They do not occur in sufficient numbers within the ZoI to be considered sensitive receptors and are therefore considered to be of Negligible impact significance with respect to vessel traffic in the dredged section of the proposed outfall pipeline route (marine section).

Common scoter is a species of high ecological value and high sensitivity to disturbance from boat traffic (Garthe and Hüppop 2004; Maclean et al. 2009; Furness and Wade 2012). Studies have found that scoters may flush when vessels are within 1km to 2km (Kaiser et al. 2006). Another study found a median flush distance from ships of 804m and a maximum flush distance of 3.2km (Schwemmer et al. 2011). Although there is a large amount of sea nearby that is outside the ZoI of the Proposed Project (which, based on the distribution of birds on the water from VPs, this species already favours), it is considered that the impact magnitude for common scoter is medium. Between March to October of all years surveys were carried out, 2,274 common scoters were recorded on the sea during VP surveys. Because 1,282 of these occurred in March (56.4%), it is considered that the ecological value of the population is high in March (giving a Moderate impact significance), and medium between April and October (resulting in a Minor impact significance). Mitigation is required to reduce the impact significance for this species during the month of March.

Red-throated diver is a species of high sensitivity to disturbance from boat traffic (Garthe and Hüppop 2004; Topping and Peterson 2011; Furness and Wade 2012). Red-throated divers are susceptible to flushing when a vessel approaches, and the distance of displacement may be substantial (Ruddock and Whitfield 2007). Like

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common scoter, most birds were recorded in open sea to the north of the dredged section of the proposed outfall pipeline route (marine section). However, it is considered that, due to their elevated sensitivity to vessel disturbance, the impact magnitude for vessel disturbance for this species is medium. Between March and October, there were 523 records of red-throated divers on the sea near the dredged section of the proposed outfall pipeline route (marine section). Of these records, 301 (57.6%) were made in March, a month during which the red-throated diver population is judged to be of high ecological value, giving a Moderate impact significance. Between April and October, the population decreases in number and is considered to be of medium ecological value, giving a Minor impact significance. Mitigation is required to reduce the impact significance for this species during the month of March.

There are a number of species of high ecological value that were present in substantial enough numbers and/or sufficiently frequently to be considered in the assessment. Garthe and Hüppop (2004) and Furness and Wade (2012) have classified these species as possessing a negligible sensitivity to vessel traffic. These are Arctic tern, black tern, black-headed gull, common gull, common tern, roseate tern, Sandwich tern and great skua. This also applies to lesser black-backed gull (a species of medium ecological value). Disturbance and displacement by vessel traffic will have a Negligible impact significance on all of these species.

All other species that were recorded were not present in substantial numbers and/or sufficiently frequently or considered to be highly sensitive to vessel disturbance near the dredged section of the proposed outfall pipeline route (marine section). They are therefore considered to have a Negligible impact significance in relation to disturbance by vessel traffic. The confidence in all the predictions in this section is near-certain. Because of the assessment above, two mitigation elements will be implemented. It will be required that the time of year when dredging and construction activity can occur is revised from March to October to April to October, to ensure that larger numbers of red- throated diver and common scoter are not potentially subjected to vessel disturbance and displacement impacts. In addition, a Vessel Management Plan (VMP) to reduce the sensitivity of potentially flightless guillemots and razorbills will be required to be in place for the duration of the construction period. Further information on these measures is provided in Section 10.9.

Disturbance/Displacement due to Vessel Traffic and Construction Noise at Proposed Marine Diffuser

Of primary concern are the qualifying species of the Ireland’s Eye SPA, which breed on the cliffs of Ireland’s Eye and are of very high ecological value. The assessment considers the breeding colony and birds using the sea away from the colony separately.

The proposed marine diffuser location is approximately 390m from the boundary of the Ireland’s Eye SPA. With a 250m working area around the diffuser, there will be a minimum standoff distance of 140m between the closest part of the working area and the Ireland’s Eye SPA boundary. This boundary is located approximately 500m from the island cliffs on the north and east coasts of Ireland’s Eye, where the nests of breeding birds are located. Therefore, there is an estimated minimum horizontal standoff distance of 645m between the nearest edge of the proposed marine diffuser working area, where vessels may be operating, and the cliffs on Ireland’s Eye where the nesting seabirds are located. In addition, there is a vertical component to this distance, likely to be of the order of several tens of metres, based on the approximate maximum cliff height of 67m on the island.

Published literature reports a wide range of disturbance and/or standoff distances for seabird colonies. Some examples include a standoff distance of 180m for mixed tern/skimmer colonies for pedestrians and boats

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(Rodgers and Smith 1995), a maximum flight initiation distance of 78m for yellow-legged gull colonies to pedestrian approach (Martinez-Abrain et al. 2008), and a 100m standoff distance between tern colonies and motor boats (Burger 1998; Rodgers and Smith 1995), which suggested that double-crested cormorants in Florida could be approached to 100m without causing ill effects. A mixed colony of fulmars, shags, herring gulls, kittiwakes, guillemots, razorbills and puffins in Scotland demonstrated virtually no reaction behaviourally or reproductively to flights by fixed-wing aircraft within 100m of the colony (Dunnet 1977).

Rojek et al. (2007) studied in detail the disturbance responses of seabird (predominantly guillemot) colonies when approached by fishing vessels over a two-year period. Birds were typically not affected by vessels passing by at extended distances, but those approaching closely elicited a range of disturbance responses. Nearly all vessel disturbances to guillemots and cormorants occurred at vessel distances of less than 100m. At one colony, 23 vessel approaches were made within 500m, of which seven resulted in disturbance responses by guillemots. Four of these responses were a heads up and/or walking movement response (considered a moderate level response). The remaining three vessel approaches resulted in flushing (very severe response). Of recorded disturbances, 78% occurred when boats approached within 50m of the colony, and all flushing events occurred within 75m. On two occasions, heads up responses occurred when boats approached to within 200m, and a vessel with a loud engine elicited heads up responses when about 800m away. The Canadian Government has published guidance relating to avoiding disturbance at seabird colonies (Canadian Government 2016). A general minimum 300m standoff distance between smaller vessels and seabird colonies is recommended, increasing to 500m for larger vessels such as cruise ships and 1km for ‘high disturbance activities (e.g. drilling, blasting)’. It is also suggested that vessels travel at steady speeds when close to seabird and waterbird colonies, moving parallel to the shore rather than approaching the colony directly. When in proximity to colonies, it is recommended that sharp or loud noises should be avoided (e.g. horns) and that a constant engine noise level is maintained (Canadian Government 2016).

Work at the proposed marine diffuser is not expected to be noisy and will occur for only a short period of time. The literature referenced above, and the guidance issued by the Canadian Government, suggests that the works at the marine diffuser will have a negligible impact magnitude on birds at the colony due to the standoff distance of 645m. As these birds have a very high ecological value, this results in a Minor impact significance.

As well as the colony itself, there will be SPA qualifying birds present within designated waters that are closer to the proposed marine diffuser than the nests.

Herring gull, kittiwake, fulmar, great black-backed gull and gannet are all highly mobile species that spend a significant amount of time in flight. Garthe and Hüppop 2004 and Furness and Wade 2012 have classified these species as possessing a negligible impact magnitude to vessel traffic and activities at the proposed marine diffuser during construction, resulting in a Minor impact significance. This can be reduced to Negligible due to the very low vulnerability of these species to boat traffic according to published literature (Garthe and Hüppop 2004; Furness and Wade 2012) and professional judgement. The same impact significance applies to peregrine because this species does not use the sea in a way that is likely to render it sensitive to disturbance by vessel traffic. Guillemot, razorbill and black guillemot are species of medium vulnerability to boat traffic (Garthe and Hüppop 2004; Furness and Wade 2012). These species may illicit a degree of disturbance by vessel activity either by flushing from the sea surface or diving when a vessel approaches. Auk species have been shown to exhibit flushing behaviour of up to 600m (Bellefleur et al. 2009; Ronconi and Clair 2002), although these studies involved

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vessels travelling at relatively high speeds. It is expected that this distance will be less for the Proposed Project, as it will involve vessels that are either stationary or travelling at low speed. During July and August, auks leave the Ireland’s Eye area to moult. In this period, some birds may be flightless (Wright and Begg 1987) and more susceptible to disturbance. Flightless birds were not recorded in large numbers during the targeted surveys in 2016 and 2017, but despite this, it is recognised that they will be present in the area in July and August.

Guillemot and razorbill were the most frequently recorded birds on the sea during the time of the year where vessels are likely to be active at the marine diffuser. The distribution of on-sea records shows that, of 8,186 guillemot recorded from the Ireland’s Eye VP, 6,897 (84.3%) were loafing, preening/bathing or roosting (Table A10.14, Appendix A10.1). The number of razorbills recorded from the Ireland’s Eye VP during the same time period was 7,449, of which 6,399 (86.0%) were recorded loafing, preening/bathing or roosting (Table A10.15, Appendix A10.1). These behaviours are activities that are not dependent on the birds being present at a specific location. It is highly likely that these activities could be undertaken at an alternative location on a temporary basis if required, without significant impacts on the population. Furthermore, the behaviours recorded indicate that the guillemot and razorbill population of the Ireland’s Eye SPA rely on waters for feeding which are located away from the marine diffuser, and thus will be unaffected by works. This is supported by published mean foraging distances of 37.8km for guillemot and 23.7km for razorbill (Thaxter et al. 2012). It is considered that, whilst disturbance and displacement of these species will occur from waters near the proposed marine diffuser on a short-term, localised and reversible basis, these waters are not critical to these populations, and there is substantial alternative habitat beyond the ZoI. Consequently, the impact magnitude is low. Because these populations can relocate if disturbed, they have been assigned a high ecological sensitivity, resulting in a Minor impact significance. For guillemot and razorbill in July and August, a very high ecological sensitivity has been assigned along with a low impact magnitude, resulting in a Moderate impact significance. Mitigation is required to reduce the impact significance for this species group during this time period.

Puffin are of below average sensitivity to vessel traffic (Garthe and Hüppop 2004; Furness and Wade 2012). Of the 742 birds recorded on the water during VP surveys, 727 (98%) were recorded from the Ireland’s Eye VP, of which 700 (96.3%) were loafing or preening (Table A10.22, Appendix A10.1). These behaviours are not dependent on the birds being present at a specific location. It is highly likely that these activities could be undertaken at an alternative location on a temporary basis if required, without significant impacts on the population. Furthermore, it indicates that the puffin population of the Ireland’s Eye SPA rely on waters for feeding which are located away from the marine diffuser, and thus will be unaffected by works. On this basis, the sensitivity of puffins to the works at the proposed marine diffuser is considered to be low, and the impact magnitude negligible. The impact significance of vessel traffic at the proposed marine diffuser for puffin is Negligible.

Black guillemots were recorded in much lower numbers than guillemot and razorbill, with 223 birds recorded on the sea from the Ireland’s Eye VP (Table A10.23, Appendix A10.1). Of these birds, 211 (94.6%) were feeding. The foraging range of black guillemot is approximately 2km (Thaxter et al. 2012). This means that black guillemot is dependent on the waters immediately adjacent to Ireland’s Eye for feeding. The Ireland’s Eye SPA encompasses a large expanse of designated waters (approximately 182ha), of which only 28.81ha (15.83% of the total designated water area) occurs within 500m of the proposed marine diffuser location. It is proposed that 500m is a highly precautionary disturbance distance for black guillemot (Canadian Government, 2016), a species known to possess only a moderate sensitivity to vessel traffic (Garthe and Hüppop 2004; Furness and Wade 2012). It is presumed that the entire area of sea around Ireland’s Eye was designated as part of the SPA due in part to its

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high suitability for foraging by the bird species of the Ireland’s Eye SPA, including black guillemot. Therefore, there remains a large proportion (84.17%) of alternative foraging/loafing/roosting habitat within the SPA boundary, all of which is within the foraging range of black guillemot. It is therefore considered that black guillemots, which could be temporarily displaced from waters directly adjacent to the proposed marine diffuser during construction, would be subject to a negligible impact magnitude, resulting in a Minor impact significance, due to activities at the proposed marine diffuser.

Both cormorant and shag are considered to be of above average sensitivity to vessel traffic (Garthe and Hüppop 2004; Furness and Wade 2012). Despite this, evidence from Burbo Bank (CMACS 2008) and Robin Rigg (E.ON/Natural Power 2012) offshore wind farms has shown that densities of cormorant increased during their construction phases. Both cormorant and shag are relatively flexible with respect to habitat use (Garthe and Hüppop 2004; Furness and Wade 2012). Both species were regularly recorded on the sea in the area around Ireland’s Eye throughout the period where vessels associated with the Proposed Project would be expected to be present at the proposed marine diffuser. These species were most frequently recorded in sectors located a large distance from the proposed marine diffuser. Their flexible habitat usage and wide distribution throughout most VP count sectors (Table A10.17, Appendix A10.1 for cormorant, Table A10.20, Appendix A10.1 for shag) suggests that these species are capable of utilising areas of sea that will be beyond the ZoI of vessel disturbance, and that they are not dependent on the area directly adjacent to the proposed marine diffuser. As a result, the impact of disturbance through vessel activity is predicted to be of negligible magnitude. Combined with the very high ecological value, this results in a Minor impact significance for these species. In addition to the Ireland’s Eye SPA species, a further three species were judged to be present is sufficient numbers or sufficiently frequently to require further examination.

Common scoter is a species of high ecological value and high sensitivity to disturbance from boat traffic (Garthe and Hüppop 2004; Maclean et al. 2009; Furness and Wade 2012). Scoters may flush upon vessels approaching at 1km to 2km distance (Kaiser et al. 2006), whilst Schwemmer et al. (2011) found a median flush distance from ships of 804m and a maximum flush distance of 3.2km. Although there is a large area of subtidal habitat nearby that is outside the ZoI of activities at the proposed marine diffuser (which common scoter already utilise in preference to the water closer to the marine diffuser), it is considered that the impact magnitude for common scoter is medium due to the species’ high sensitivity to vessel traffic. Between March to October of all years in which surveys were carried out, 402 common scoters were recorded on the sea near Ireland’s Eye. Because 210 (52.2%) of these occurred in March, it is considered that the ecological value of the population is high in March, giving a Moderate impact significance, and medium between April and October, resulting in a Minor impact significance. Mitigation is required to reduce the impact significance for this species during the month of March.

The other two species requiring consideration are Sandwich tern and black-headed gull. Garthe and Hüppop (2004) and Furness and Wade (2012) have classified both species as possessing a negligible sensitivity to vessel traffic. The impact significance for these species as a result of construction of the proposed marine diffuser is therefore Negligible.

All other species were not present in substantial numbers and/or sufficient frequently or considered to be highly sensitive to vessel disturbance near Ireland’s Eye and the proposed marine diffuser. They are therefore considered to have a Negligible impact significance in relation to disturbance by the construction of the proposed marine diffuser.

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The confidence in all the predictions in this section is near-certain. The exception is the impacts on the Ireland’s Eye SPA seabird colony and the sensitive qualifying species away from the colony (guillemot, razorbill, black guillemot, cormorant and shag), which are of probable certainty.

It is proposed that two mitigation elements will be required. Firstly, a temporal restriction to prevent dredging and construction activity in March is required to ensure that large numbers of common scoter are not subjected to vessel disturbance and displacement impacts. The second requirement is that a VMP will be implemented to reduce the sensitivity of potentially flightless guillemots and razorbills during July and August. The VMP will also increase the certainty of impact predictions on the Ireland’s Eye SPA seabird colony and sensitive qualifying species away from the colony to near-certain by imposing restrictions on vessel movement. Further information on these measures is provided in Section 10.9. Impacts on Prey of Birds by Suspended Sediments Caused by Dredging of the Proposed Outfall Pipeline Route (Marine Section)

Chapter 9 Biodiversity (Marine) discusses the impact of sediment plumes from the dredging of the proposed outfall pipeline route (marine section) on fish. It is concluded that the impacts associated with the plume will be short-term and of negligible to no magnitude on fish. Therefore, the impact significance on all ornithological species is Negligible.

10.6.2 Operational Phase Because of the nature of the Proposed Project and its operation, which does not require the routine presence of significant surface activities in or near Baldoyle Bay or Ireland’s Eye, there are no impacts predicted on ornithological interests during the Operational Phase. Therefore, the impact significance on all ornithological species is Negligible.

10.7 ‘Do Nothing’ Impact The impact to the current ecological status based on a ‘do nothing’ scenario is likely to be of Negligible significance.

10.8 Cumulative Impacts The list of other projects considered in Chapter 23 Cumulative Impacts and Environmental Interactions in Volume 3 Part A of this EIAR has been reviewed, and it is concluded that none of them will result in cumulative impacts on estuarine or marine ornithological interests in combination with the Proposed Project.

10.9 Mitigation Measures

10.9.1 Construction Phase – Estuarine Ornithology A summary of mitigation measures for estuarine ornithology is presented in Table 10.15.

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Table 10.15: Summary of Proposed Impacts and Mitigation Requirements for Estuarine Ornithology

Operation Area at Risk Sensitive Receptor and Measures Required Impact Significance Construction of Habitats within and All SCIs and named Installation of hoarding at both proposed temporary proposed adjacent to Baldoyle Bay qualifying species of the construction compounds for duration of Construction temporary SPA within 50m to 500m Baldoyle Bay SPA, in Phase. construction of each microtunnelling addition to other waders and compound no. 9 compound, depending on waterbirds using these and no. 10 species habitats

Installation of Hoarding

A 2.4m high hoarding will be used for the duration of the construction works at both microtunnelling compounds (proposed temporary construction compounds no. 9 and 10). Compound construction will not proceed without the installation of hoarding around the entire perimeter of each compound and any associated access track. The deployment of this hoarding will mean that works within the microtunnelling compounds will occur out of sight of birds in the Baldoyle Bay SPA, meaning that disturbance impacts on birds are reduced to a very low level (Cutts et al. 2013). Ikuta and Blumstein (2003) found that protective barriers allow birds to behave as they would in an undisturbed environment. To avoid disturbance to wintering birds, the hoarding will only be erected and uninstalled between April and August under supervision by a professional ecologist.

10.9.2 Construction Phase – Marine Ornithology A summary of mitigation measures for marine ornithology is presented in Table 10.16.

Table 10.16: Summary of Proposed Impacts and Mitigation Requirements for Marine Ornithology

Operation Area at Risk Sensitive Receptor and Measures Required Impact Significance Construction of Extent of sea around Seabirds near Adherence to VMP (see Appendix A10.2 in Volume 3 microtunnelling / microtunnelled microtunnelled Part B of this EIAR), including withdrawing from area subsea interface section/subsea section section/subsea section in event of large-scale auk movement towards of the proposed interface and fibre optic interface vessels outfall pipeline cable crossing route (marine section) and fibre optic cable crossing Construction of Extent of sea in the Guillemot and razorbill (July Adherence to VMP (see Appendix A10.2 in Volume 3 subsea section dredged section of the and August only): Moderate Part B of this EIAR), including withdrawing from area of the proposed proposed outfall pipeline in event of large-scale auk movement towards outfall pipeline route (marine section) in vessels Red-throated diver (March route (marine which construction vessels only): Moderate Ensuring consruction activities are nor carried out in section) are operating March, instead taking place from April to October

only. Common scoter (March

only): Moderate

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Operation Area at Risk Sensitive Receptor and Measures Required Impact Significance Construction of Extent of sea around Guillemot and razorbill (July Adherence to VMP (see Appendix A10.2 in Volume 3 proposed marine marine diffuser location, and August only): Moderate Part B of this EIAR), including use of bird observer diffuser including section of during July and August and withdrawing from area in Ireland’s Eye SPA Common scoter (March event of large-scale auk movement towards vessels only): Moderate Adjustment to temporal restriction of marine construction activities from March to October, to April to October

Vessel Management Plan

It should be noted that the VMP has been prepared by the Proposed Project ornithologist.

Due to the potential presence of large numbers of birds with very high ecological value and also the sensitivity of breeding seabirds within and near the Ireland’s Eye SPA, it will be necessary to put in place a VMP (see Appendix A10.2 in Volume 3 Part B of this EIAR). The VMP will have two key functions.

The first is to ensure that the Ireland’s Eye SPA boundary is not unnecessarily approached or crossed by construction vessels working on the proposed marine diffuser and subsea section of the proposed outfall pipeline route (marine section) at any time during the Construction Phase. This will also increase the certainty that the impact significance on the breeding colony itself during construction will be Negligible. Every vessel used on the Proposed Project will have a copy of the VMP and the crews will be acquainted with the boundary of Ireland’s Eye SPA and the ornithological importance of these waters.

The second is to ensure the protection of rafting auks leaving the Ireland’s Eye colony in July to mid-August. These birds are flightless, and thus particularly susceptible to disturbance by vessels. Whilst such rafts tend to immediately leave the area to moult in locations far from the shore, unfavourable winds can result in them being unable to control the direction in which they are travelling when leaving their colony. A bird observer (present either on the island or a vessel) will keep watch in July to mid-August only, noting wind direction and monitoring whether any auks that may be on the water are drifting out towards the proposed marine diffuser.

In the event of a sighting of rafting auks between Ireland’s Eye and the proposed marine diffuser construction area, vessels on-site will be informed. All vessels will be obliged to immediately report the sightings to the other Proposed Project vessels with exact position of sighting, and reduce speed to less than 10 knots if within 1km of the reported sighting. Vessels should thereafter avoid coming closer than 1km to any rafting auks, and keep extra lookout for rafting auks. This may result in vessels having to temporarily leave the work area until rafting auks are no longer present. If this does occur, it is not expected that such birds would persist in the area.

Adjustment of Temporal Restrictions to Marine Construction To avoid disturbance to high ecological value populations of red-throated diver and common scoter, the time period in which marine construction activities can occur will be revised from March to October to April to October.

10.9.3 Operational Phase – Estuarine Ornithology No impacts are predicted on estuarine ornithological interests during the Operational Phase. As a result, no mitigation measures are proposed.

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10.9.4 Operational Phase – Marine Ornithology No impacts are predicted on marine ornithological interests during the Operational Phase. As a result, no mitigation measures are proposed.

10.10 Residual Impacts

10.10.1 Estuarine Ornithology The installation of appropriate hoarding will mitigate the Major impact significance for any species of very high ecological value and Moderate impact significance for a range of other species. The impact magnitude will be reduced from medium to negligible. This results in an impact significance of Minor for species of very high ecological value and Negligible for all other species. In both cases, the residual level of impact significance is considered not significant.

10.10.2 Marine Ornithology The provision of an appropriate VMP will mitigate the Moderate impact significance currently predicted for guillemot and razorbill in July and August in the dredged section of the proposed outfall pipeline route (marine section) and at the marine diffuser. The impact magnitude will be reduced from low to negligible if this mitigation is incorporated. The impact significance will change from a pre-mitigation value of Moderate to a residual value of Minor. The residual level of impact significance is considered not significant.

The alteration of the time period during which marine construction can occur results in the majority of common scoter and red-throated divers in the area leaving before construction commences. This reduces the ecological value of the populations that can be impacted from high value to medium value. Upon acceptance of this restriction, the pre-mitigation impact significance of Moderate will change to a residual value of Minor. The residual level of impact significance is considered not significant.

10.11 References Bellefleur, D., Lee, P. and Ronconi, R.A. (2009). The impact of recreational boat traffic on marbled murrelets (Brachyramphus marmoratus). Journal of Environmental Management 90: 531-538.

Colhoun K and Cummins S (2013), Birds of Conservation Concern in Ireland 2014 –2019. Irish Birds 9: 523—544.

BTO (2016a). WeBS Core Counts Method. Available at: http://www.bto.org/volunteer-surveys/webs/taking- part/core-counts-methods.

BTO (2016b). WeBS Low Tide Counts Method. Available at: http://www.bto.org/volunteer-surveys/webs/taking- part/low-tide-counts.

BTO (2018). 2015/16 Threshold Database [online]. Available at https://www.bto.org/sites/default/files/threshold_levels_1516_0.xls.

Burger J. (1998). Effects of Motorboats and Personal Watercraft on Flight Behaviour over a Colony of Common Terns. The Condor 100: 528-534.

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Canadian Government (2017). Seabird and waterbird colonies: avoiding disturbance [online]. Available at https://www.canada.ca/en/environment-climate-change/services/avoiding-harm-migratory-birds/seabird-waterbird- colonies-disturbance.html (accessed 11/06/2018).

Chartered Institute of Ecology and Environmental Management (2016). Guidelines for Ecological Impact Assessment in the UK and Ireland: Terrestrial, Freshwater and Coastal. Second Edition. Chartered Institute of Ecology and Environmental Management.

CMACS (2009) Burbo offshore Wind Farm. Year 2 Post-construction ornithology report. Report prepared by Ltd and Avian Ecology on behalf of SeaScape Energy.

Cutts N., Hemingway K. and Spencer J. (2013). Waterbird Disturbance Mitigation Toolkit: Informing Estuarine Planning & Construction Projects. Produced by the Institute of Estuarine and Coastal Studies.

Dunnet, G.M. 1977. Observations on the effects of low-flying aircraft at seabird colonies on the coast of Aberdeenshire, Scotland. Biological Conservation 12:55-63.

Environmental Protection Agency (2017). Draft Guidelines on the Information to be Contained in Environmental Impact Assessment Reports.

Fingal County Council (2010). Fingal Biodiversity Action Plan 2010-2015.

Fingal County Council (2017). Fingal Development Plan 2017-2023.

Fingal County Council (2013) Portmarnock South Local Area Plan

E.ON/Natural Power (2012). Analysis of Marine Ecology Monitoring Plan Data from the Robin Rigg Offshore Wind Farm, Scotland (Operational Year 2). Technical Report Chapter 5: Birds.

Furness B. and Wade H. (2012). Vulnerability of Scottish Seabirds to Offshore Wind Turbines. Macarthur Green Ltd. Report for Scottish Government.

Garthe S. and Hüppop O. (2004). Scaling possible adverse effects of marine wind farms on seabirds: developing and applying a vulnerability index. Journal of Applied Ecology 41 (4) p. 724-734.

Gilbert G., Gibbons D.W. and Evans J. (1998). Bird Monitoring Methods. RSPB, Sandy.

Irish Wetland Bird Survey (2018). I-WeBS Database [online]. Available at https://f1.caspio.com/dp/f4db3000060acbd80db9403f857c.

Ikuta L.A. and Blumstein D.T. (2003). Do fences protect birds from human disturbance? Biological Conservation 112(3):447-452.

Kaiser M.J., Galanidi M., Showler D.A. and Sutherland W.J. (2006). Distribution and behaviour of Common Scoter Melanitta nigra relative to prey resources and environmental parameters. Ibis 148(s1):110 – 128.

Maclean, I.M.D., Wright, L.J., Showler, D.A. and Rehfisch, M.M. (2009). A review of assessment methodologies for offshore windfarms. BTO Report commissioned by COWRIE Ltd.

Martinez-Abrain A., Oro D., Conesa D. and Jimenez J. (2008). Compromise between seabird enjoyment and disturbance: the role of observed and observers. Environmental Conservation 35 (2): 104–108.

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Rodgers J.A. and Smith H.T. (1995). Set‐Back Distances to Protect Nesting Bird Colonies from Human Disturbance in Florida. Conservation Biology 9 (1) p. 89-99.

Rojek N.A., Parker M.W.Carter H.R. and McChesney G.J. (2007). Aircraft and vessel disturbances to Common Murres Uria aalge at breeding colonies in central California, 1997-1999. Marine Ornithology 35 (1) p61-69.

Ronconi, R.A. and Clair, C.C.S. (2002). Management options to reduce boat disturbance on foraging black guillemots (Cepphus grylle) in the Bay of Fundy. Biological Conservation 108: 265-271.

Ruddock M. and Whitfield D.P. (2007). A Review of Disturbance Distances in Selected Bird Species. A report from Natural Research (Projects) Ltd to Scottish Natural Heritage.

Santos C.D., Miranda A.C., Granadeiro J.P., Lourenço P.M., Saraiva S. and Palmeirim J.M. (2010). Effects of artificial illumination on the nocturnal foraging of waders. Acta Oecologica Volume 36, Issue 2, March–April 2010, Pages 166-172.

Schwemmer, P., Mendel, B., Sonntag, N., Dierschke, V. and Garthe, S. (2011). Effects of ship traffic on seabirds in offshore waters: implications for marine conservation and spatial planning. Ecological Applications 21: 1851- 1860.

Thaxter, C. B., Lascelles, B., Sugar, K., Cook, A. S. C. P., Roos, S., Bolton, M., Langston, R. H. W., Burton, N. H. K. (2012). Seabird Foraging Ranges as a Preliminary Tool for Identifying Candidate Marine Protected Areas. Biological Conservation. doi:10.1016/j.biocon.2011.12.009.

Tierney N., Whelan R., Boland H. and Crowe O. (2017). The Dublin Bay Birds Project Synthesis 2013-2016. BirdWatch Ireland, Kilcoole, Co. Wicklow.

Topping C. and Peterson I.K. (2011). Report on a Red-throated Diver Agent-based Model To Assess the Cumulative Impact from Offshore Wind Farms. Report commissioned by the Environmental Group.

Wakefield E.D., Owen E., Baer J., Carroll M.J., Daunt F., Dodd, S.G., Green J.A., Guilford T., Mavor R.A., Miller P.I., Newell M.A., Newton S.F., Robertson G.S., Shoji A., Soanes L.M., Votier S.C., Wanless S. and Bolton M. (2017). Breeding density, fine‐scale tracking, and large‐scale modeling reveal the regional distribution of four seabird species. Ecological Applications, 27: 2074-2091. doi:10.1002/eap.1591.

Wright P.J. and Begg G.S. (1997). A spatial comparison of Common Guillemots and sandeels in Scottish waters. ICES Journal of Marine Science 54: 578-592.

Directives and Legislation European Communities (Birds and Natural Habitats) Regulations 2011 – S.I. No. 477 of 2011

European Communities (Quality of Salmonid Waters) Regulations 1988 – S.I. No. 293 of 1988

European Union (1992). Council Directive 92/43/EEC on the conservation of natural habitats and of wild fauna and flora [1992].

European Union (2009). Directive 2009/147/EC of 30 November 2009 of the European Parliament and of the Council on the conservation of wild birds [2009].

Wildlife Acts 1976-2002

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NPWS – SPA Conservation Objectives NPWS (2013) Conservation Objectives: Baldoyle Bay SPA 004016. Version 1. National Parks and Wildlife Service, Department of Arts, Heritage and the Gaeltacht.

NPWS (2018) Conservation objectives for Ireland's Eye SPA [004117]. Generic Version 6.0. Department of Culture, Heritage and the Gaeltacht

NPWS (2015) Conservation Objectives: North Bull Island SPA 004006. Version 1.National Parks and Wildlife Service, Department of Arts, Heritage and the Gaeltacht.

NPWS (2013) Conservation Objectives: Malahide Estuary SPA 004025. Version 1. National Parks and Wildlife Service, Department of Arts, Heritage and the Gaeltacht.

NPWS (2018) Conservation objectives for Howth Head Coast SPA [004113]. Generic Version 6.0. Department of Culture, Heritage and the Gaeltacht.

NPWS (2015) Conservation Objectives: South Dublin Bay and River Tolka Estuary SPA 004024. Version 1. National Parks and Wildlife Service, Department of Arts, Heritage and the Gaeltacht.

NPWS (2013) Conservation Objectives: Rogerstown Estuary SPA 004015. Version 1. National Parks and Wildlife Service, Department of Arts, Heritage and the Gaeltacht.

NPWS (2018) Conservation objectives for Lambay Island SPA [004069]. Generic Version 6.0. Department of Culture, Heritage and the Gaeltacht.

NPWS (2018) Conservation objectives for Dalkey Islands SPA [004172]. Generic Version 6.0. Department of Culture, Heritage and the Gaeltacht.

NPWS (2018) Conservation objectives for Skerries Islands SPA [004122]. Generic Version 6.0. Department of Culture, Heritage and the Gaeltacht.

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Greater Dublin Drainage Project Irish Water

Environmental Impact Assessment Report: Volume 3 Part A of 6

Chapter 11 Biodiversity (Terrestrial and Freshwater Aquatic) June 2018

Envir onmental Impact Assessment Report: Vol ume 3 Part A of 6 Irish Water

Environmental Impact Assessment Report: Volume 3 Part A of 6

Contents 11. Biodiversity (Terrestrial and Freshwater Aquatic) ...... 4 11.1 Introduction ...... 5 11.1.1 Chapter Structure ...... 7 11.1.2 Zone of Influence ...... 8 11.2 Methodology – Terrestrial and Freshwater Aquatic ...... 8 11.2.1 Desktop Data Sources and Consultation ...... 8 11.2.2 Local Planning Policy ...... 10 11.2.3 Field Survey ...... 12 11.2.4 Valuation and Impact Assessment ...... 20 11.2.5 Compliance with the Water Framework Directive ...... 23 11.3 Baseline Environment – Terrestrial Flora and Fauna...... 24 11.3.1 Designated Sites ...... 24 11.3.2 Terrestrial Habitats ...... 26 11.3.3 Bats ...... 31 11.3.4 Mammals (Other than Bats) ...... 38 11.3.5 Farmland Birds ...... 40 11.3.6 Other Species Groups ...... 41 11.3.7 Summary Valuation of Terrestrial Biodiversity Features ...... 42 11.4 Impact of the Proposed Project on Terrestrial Biodiversity – Construction Phase ...... 42 11.4.1 Designated Sites ...... 45 11.4.2 Terrestrial Habitats ...... 46 11.4.3 Bats ...... 48 11.4.4 Mammals (Other than Bats) ...... 50 11.4.5 Farmland Birds ...... 51 11.4.6 Other Species Groups ...... 51 11.5 Impact of the Proposed Project on Terrestrial Biodiversity – Operational Phase ...... 52 11.5.1 Designated Sites ...... 54 11.5.2 Terrestrial Habitats ...... 55 11.5.3 Bats ...... 55 11.5.4 Mammals (Other than Bats) ...... 55 11.5.5 Farmland Birds ...... 55 11.5.6 Other Species Groups ...... 56 11.6 ‘Do Nothing’ Impact on Terrestrial Biodiversity ...... 56 11.7 Mitigation Measures – Terrestrial Biodiversity ...... 56 11.7.1 Overarching Measures ...... 56

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11.7.2 Designated Sites (All Proposed Projects Elements) ...... 56 11.7.3 Terrestrial Habitats ...... 56 11.7.4 Bats ...... 57 11.7.5 Mammals (Other than Bats) ...... 60 11.7.6 Farmland Birds ...... 60 11.7.7 Other Species Groups ...... 61 11.8 Residual Impacts – Terrestrial Biodiversity ...... 61 11.8.1 Difficulties Encountered in Compiling Required Information ...... 63 11.9 Baseline Environment – Freshwater Aquatic Biodiversity ...... 63 11.9.1 Field Survey Results...... 67 11.10 Impact of the Proposed Project on Freshwater Aquatic Biodiversity – Construction Phase...... 77 11.11 Impact of the Proposed Project on Freshwater Aquatic Biodiversity – Operational Phase ...... 81 11.12 Summary of Potential Impacts in the Absence of Mitigation Measures ...... 82 11.13 ‘Do Nothing’ Impact on Freshwater Aquatic Biodiversity ...... 84 11.14 Mitigation Measures – Freshwater Aquatic Biodiversity...... 84 11.14.1 Construction Phase ...... 84 11.14.2 Operational Phase ...... 91 11.15 Residual Impacts – Freshwater Aquatic Biodiversity ...... 91 11.16 References ...... 93

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11. Biodiversity (Terrestrial and Freshwater Aquatic)

This Chapter of the Environmental Impact Assessment identifies, describes and assesses the likely significant effects of the proposed Greater Dublin Drainage Project (hereafter referred to as the Proposed Project) on terrestrial and freshwater aquatic biodiversity resources. A section of the proposed outfall pipeline route (marine section) is to be:  Located within Rockabill to Dalkey Island Special Area of Conservation (SAC);  Located in proximity to Ireland’s Eye Special Protection Area (SPA); and  Tunnelled below Baldoyle Bay SAC, SPA, Ramsar site and proposed Natural Heritage Area (pNHA)

Approximately 60% of the Proposed Project, from the commencement of the proposed outfall pipeline route (marine section) from the R106 Coast Road to 1km north-east of Ireland’s Eye, is located within transitional or buffer zones of Dublin Bay UNESCO Biosphere Reserve, and it is to be tunnelled under a core area of the Biosphere Reserve. Qualifying features of European Sites are located within the Zone Of Influence (ZOI) of the Proposed Project. There are a number of potential significant effects upon both terrestrial and freshwater aquatic biodiversity resources that could occur during the Construction Phase. In addition, potential significant effects upon some freshwater aquatic resources could occur during the Operational Phase. These potential significant effects upon biodiversity features located within the ZOI of the Proposed Project include:  loss, deterioration and fragmentation of terrestrial and freshwater aquatic habitats; and  disturbance to, displacement of or reduction in habitat availability for protected species.

Construction Phase effects are generally temporary, with the exception of the permanent loss of terrestrial habitats of site-level or local importance at the proposed Abbotstown pumping station and Wastewater Treatment Plant. Operational Phase effects are only likely to occur if wastewater infrastructure fails to function correctly and wastewater is released to the aquatic environment.

Mitigation measures have been incorporated into the Proposed Project to offset potential significant adverse effects on terrestrial and freshwater aquatic biodiversity resources. Trenchless techniques will be used for all watercourse crossings. An Ecological Clerk of Works will supervise or implement a number of mitigation measures, including:  Provision of toolbox talks to appointed contractor(s);  Establishing ecological buffer zones;  Seasonal restrictions on vegetation clearance;  Replanting of hedgerows to be removed;  Obtaining wildlife disturbance licences from National Parks and Wildlife Service to fell trees, close badger setts and translocate smooth newts; and  Erection of bat boxes.

There are no predicted significant residual effects upon terrestrial and freshwater aquatic biodiversity resources, following the implementation of mitigation measures.

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11.1 Introduction This Chapter of the Environmental Impact Assessment Report (EIAR) identifies, describes and assesses the direct and indirect likely significant impacts of the Greater Dublin Drainage Project (hereafter referred to as the Proposed Project) on biodiversity. The Proposed Project will form a significant component of a wider strategy to meet future wastewater treatment requirements within the Greater Dublin Area as identified in a number of national, regional and local planning policy documents. The plant, equipment, buildings and systems associated with the Proposed Project will be designed, equipped, operated and maintained in such a manner to ensure a high level of energy performance and energy efficiency. The table below includes a summary of the Proposed Project elements. A full description of the Proposed Project is detailed within Volume 2 Part A, Chapter 4 Description of the Proposed Project, of this EIAR.

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Proposed Project Outline Description of Proposed Project Element Element

Proposed  WwTP to be located on a 29.8 hectare (ha) site in the townland of Clonshagh (Clonshaugh) in Fingal.  500,000 population equivalent wastewater treatment capacity. Wastewater  Maximum building height of 18m. Treatment Plant  Sludge Hub Centre (SHC) to be co-located on the same site as the WwTP with a sludge handling and (WwTP) treatment capacity of 18,500 tonnes of dry solids per annum.  SHC will provide sustainable treatment of municipal wastewater sludge and domestic septic tank sludges generated in Fingal to produce a biosolid end-product.  Biogas produced during the sludge treatment process will be utilised as an energy source.  Access road from the R139 Road, approximately 400m to the southern boundary of the site.  Egress road, approximately 230m from the western boundary of the site, to Clonshaugh Road.  A proposed temporary construction compound to be located within the site boundary. Proposed  Abbotstown pumping station to be located on a 0.4ha site in the grounds of the National Sports Campus at Abbotstown. Abbotstown pumping  Abbotstown pumping station will consist of a single 2-storey building with a ground level floor area of 305m2 station and maximum height of 10m and a below ground basement 17m in depth with floor area of 524m2 incorporating the wet/dry wells.  The plan area of the above ground structure will be 305m2 and this will have a maximum height of 10m.  A proposed temporary construction compound to be located adjacent to the Abbotstown pumping station site. Proposed orbital  The orbital sewer route will intercept an existing sewer at Blanchardstown and will divert it from this point to the WwTP at Clonshagh. sewer route  Constructed within the boundary of a temporary construction corridor.  13.7km in length; 5.2km of a 1.4m diameter rising main and 8.5km of a 1.8m diameter gravity sewer.  Manholes/service shafts/vents along the route.  Odour Control Unit at the rising main/gravity sewer interface.  Proposed temporary construction compounds at Abbotstown, Cappoge, east of Silloge, Dardistown and west of Collinstown Cross to be located within the proposed construction corridor. Proposed North  The NFS will be intercepted in the vicinity of the junction of the access road to the WwTP with the R139 Road in lands within the administrative area of Dublin City Council. Fringe Sewer (NFS)  NFS diversion sewer will divert flows in the NFS upstream of the point of interception to the WwTP. diversion sewer  600m in length and 1.5m in diameter.  Operate as a gravity sewer between the point of interception and the WwTP site. Proposed outfall  Outfall pipeline route (land based section) will commence from the northern boundary of the WwTP and will run to the R106 Coast Road. pipeline route (land  5.4km in length and 1.8m in diameter. based section)  Pressurised gravity sewer.  Manholes/service shafts/vents along the route.  Proposed temporary construction compounds (east of R107 Malahide Road and east of Saintdoolaghs) located within the proposed construction corridor. Proposed outfall  Outfall pipeline route (marine section) will commence at the R106 Coast Road and will terminate at a discharge location approximately 1km north-east of Ireland’s Eye. pipeline route  5.9km in length and 2m in diameter. (marine section)  Pressurised gravity tunnel/subsea (dredged) pipeline.  Multiport marine diffuser to be located on the final section.  Proposed temporary construction compounds (west and east of Baldoyle Bay) to be located within the proposed construction corridor. Proposed Regional  Located on an 11ha site at Newtown, Dublin 11.  Maximum building height of 15m. Biosolids Storage  Further details and full impact assessment are provided in Volume 4 Part A of this EIAR. Facility

The total Construction Phase will be approximately 48 months, including a 12 month commissioning period to the final Operational Phase. The Proposed Project will serve the projected wastewater treatment requirements of existing and future drainage catchments in the north and north-west of the Dublin agglomeration, up to the Proposed Project’s 2050 design horizon. This Chapter contains a description of both the terrestrial and freshwater biodiversity features of the baseline environment within the planning application area and within a wider zone of influence (ZoI) near the Proposed Project.

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Biodiversity encompasses a variety of life on earth; therefore, biodiversity assessments are typically divided into specialist subject areas. This Chapter of this EIAR comprises an assessment of the likely significant impacts of the Proposed Project on terrestrial biodiversity and freshwater biodiversity features. Particular attention to species and habitats protected under Council Directive 92/43/EEC on the conservation of natural habitats and of wild fauna and flora (Habitats Directive) is given where applicable to terrestrial and freshwater biodiversity features. Further detailed analysis is given to marine species and habitats protected under the Habitats Directive in Chapter 9 Biodiversity (Marine) in Volume 3 Part A of this EIAR. More detailed analysis of species and habitats protected under Directive 2009/147/EC of 30 November 2009 of the European Parliament and of the Council on the conservation of wild birds (the Birds Directive) is given in Chapter 10 Biodiversity (Marine Ornithology).

The biodiversity assessments contained in Chapter 9 Biodiversity (Marine), Chapter 10 Biodiversity (Marine Ornithology) and this Chapter are based on Chapter 4 Description of the Proposed Project and the Outline Construction and Environmental Management Plan (CEMP). They are supported, as necessary, by other specialist assessments of the EIAR, including for example, Chapter 8 Marine Water Quality, Chapter 15 Noise and Vibration and Chapter 17 Hydrology and Hydrogeology.

This Chapter should be read with the following figures and appendices:  Volume 5, Figure 11.1 Special Areas of Conservation to Figure 11.4 Dublin Bay UNESCO Biosphere Reserve;  Volume 5, Figure 11.5 Habitat Survey Result (1 of 6) to 11.10 Habitat Survey Results (6 of 6);  Volume 3 Part B, Appendix A11.1 Bat Survey and Assessment 2017;  Volume 3 Part B, Appendix A11.2 Botanical Survey at Portmarnock;  Volume 3 Part B, Appendix A11.3 Ecological Survey for Smooth Newt; and  Natura Impact Statement (standalone report). Note that figures illustrating mammal survey results indicate the location of badger setts, and these figures have been supplied to the An Bord Pleanála (ABP) as a confidential appendix. Please also note that the terrestrial biodiversity impact assessment of the proposed RBSF aspect of the Proposed Project is addressed in Chapter 6 Biodiversity in Volume 4 Part A of this EIAR.

11.1.1 Chapter Structure The structure of this Chapter has been divided into terrestrial biodiversity (Section 11.2 to Section 11.8) and freshwater aquatic biodiversity (Section 11.9 to Section 11.15). Section 11.2 details the methodology for both terrestrial and freshwater aquatic biodiversity assessments. Section 11.3 to Section 11.8 provide the terrestrial biodiversity assessment of the likely impacts for the Construction Phase and Operational Phase of the Proposed Project. Section 11.9 to Section 11.15 provide the freshwater aquatic biodiversity assessment of the likely impacts for the Construction Phase and Operational Phase of the Proposed Project. This Chapter identifies relevant terrestrial and freshwater aquatic biodiversity receptors within the planning application area and a ZoI of the Proposed Project and provides baseline data against which future changes can be assessed. It also assesses the general status of the potentially affected watercourses from an ecological and fisheries perspective in the context of downstream catchments, coastal Special Areas of Conservation (SACs) and Special Protection Areas (SPAs).

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11.1.2 Zone of Influence From a terrestrial biodiversity perspective, the study area was defined as the footprint of the Proposed Project plus a 1km radius surrounding the Proposed Project boundary. The Proposed Project passes through coastal and farmland habitats on the northern fringe of the urban fabric of Dublin’s suburbs which are categorised at the lower end of the scale of ecological values set out in Table 11.6. Terrestrial habitats occurring within and in close proximity to the Proposed Project boundary could clearly be adversely influenced by activities associated with the Proposed Project, but they are not highly groundwater dependant habitat types. There is no possibility of activities associated with the Proposed Project adversely influencing terrestrial habitats occurring more than 1km from the Proposed Project boundary. A change in terrestrial species behaviour is triggered by noise or visual stimuli. Species occurring within and in close proximity to the Proposed Project boundary can be adversely influenced by activities associated with the Proposed Project, but as the distance from the Proposed Project increases, the likelihood of terrestrial species being adversely affected decreases. Noise and visual stimuli that is more than 1km away from the Proposed Project boundary and that significantly affects species behaviour is unlikely to be associated with the Proposed Project. At this distance, noise or visual stimuli resulting from activities associated with the Proposed Project will not exist, being replaced by stimuli occurring much nearer to the species. On this basis, it is the view of the authors that beyond this distance, no terrestrial biodiversity receptor could be influenced by the Construction Phase or the Operational Phase of the Proposed Project.

From a freshwater aquatic biodiversity perspective, the ZoI includes the sub-catchments and catchment in which the Proposed Project lies, as defined by the Environmental Protection Agency (EPA) for the purposes of the implementation of Directive 2000/60/EC of 23 October 2000 of the European Parliament and of the Council establishing a framework for the Community action in the field of water policy (the Water Framework Directive (WFD)), and includes downstream receptors in the marine environment and designated sites. The relevant sub-catchments and their EPA codes are the Tolka (Tolka_SC_020) and the Mayne (Mayne_SC_010). The relevant catchment is the Liffey and Dublin Bay Catchment. The Proposed Project boundary is wholly contained within these land based sub-catchments. The relevant marine receptors are the estuary transitional waterbodies and the Irish Sea.

11.2 Methodology – Terrestrial and Freshwater Aquatic

11.2.1 Desktop Data Sources and Consultation A desktop review of relevant environmental data and anecdotal information was carried out to identify features of biodiversity value within the ZoI. Consultations were undertaken with the following organisations of particular relevance to terrestrial and freshwater biodiversity, flora and fauna:

 National Parks and Wildlife Service (NPWS);  BirdWatch Ireland;  Fingal County Council (FCC);  Botanical Society of Britain & Ireland;  National Biodiversity Data Centre (NBDC); and  Inland Fisheries Ireland (IFI). The following databases were consulted to retrieve biodiversity data:

 NPWS Maps & Data (NPWS 2017);  National Biodiversity Data Centre Records & Mapping (NDBC 2017);

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 Review of Ordnance Survey Ireland mapping and aerial photography of the Proposed Project area and its environs;  EPA Water Quality Data (EPA 2017);  WFD Ireland Water Maps (see www.wfdireland.ie);  Fishing in Ireland – An angler’s guide to fishing in Ireland (IFI 2017);  IFI WFD Fish Data (see www.wdfish.ie); and  Invasive Species Ireland (Invasive Species Ireland 2017). Other than establishing the occurrence or otherwise of biodiversity features within the ZoI of the Proposed Project, the results of desktop data gathered were used to inform and direct the detailed field surveys.

Non-Statutory Consultation

The issues raised as a result of non-statutory consultation on the Proposed Project are included in Table 11.1.

Table 11.1: Issues Raised During Non-Statutory Consultation on the Proposed Project

Stakeholder Date Submission Details Environmental Impact Received Assessment Report Chapter Reference BirdWatch 12  Location of the WwTP (site boundary proposed at 50m from  Section 11.9 to Section Ireland December Cuckoo stream, tributary of the Mayne River – struggling with 11.14 provide the 2013 ecological status). assessment of the Proposed Project on aquatic biodiversity.

Inland 11  Environmental Impact Statement (EIS) should include an  Sections 11.3 and 11.9 Fisheries December assessment establishing the current baseline ecological provide the baseline Ireland (IFI) 2013 conditions, detail construction and operational activities and ecological conditions. predict the impact of future changes to the baseline.  See Section 11.2.5 and  Water quality assessment should be carried out in accordance Table 11.5, which with all relevant existing national and European legislation. demonstrate compliance  The EIS should provide a full and detailed evaluation on the with the WFD. likely impacts of the complete project on groundwater,  Chapters 9 to 11 provide a freshwater, estuarine and coastal ecology. full and detailed evaluation  Mitigation strategies to be developed to avoid impacts on water on the likely impacts of the quality and habitat ecology. All measures necessary should be Proposed Project on taken to ensure protection of local aquatic ecological integrity, in freshwater, estuarine and the first place by complete impact avoidance and, as a coastal ecology. Chapter secondary approach, through mitigation by reduction and 17 Hydrology and remedy. Hydrogeology provides  The EIS should assess the predicted impacts of noise and details on groundwater. vibration during the construction and operation of the Proposed  Sections 11.7 and 11.14 of Project. this Chapter (along with Chapter 9) outline details of mitigation measures for water quality and habitat ecology.  Section 11.10 addresses potential impacts of noise and vibration during the construction of the Proposed Project on

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Stakeholder Date Submission Details Environmental Impact Received Assessment Report Chapter Reference fisheries. No noise impacts are predicted during the Operational Phase.

Department of 10 January  With regard to EIS, an ecological survey of the entire Proposed  Chapters 9 to 11 provide Arts, Heritage, 2014 Project site and pipeline routes should be carried out; Where an ecological survey of the Regional, ex situ impacts are possible, survey work may be required entire Proposed Project Rural and outside of the project sites. The impact of the development on and an impact assessment Gaeltacht the flora, fauna and habitats present should be assessed. In of the development on Affairs/ particular, the impact of the proposed development should be flora, fauna and habitats. National Parks assessed, where applicable, with regard to legislation relating to  Natura Impact Statement and Wildlife habitats and species. (NIS) completed in Service  Project should be subject to Appropriate Assessment Screening accordance with Article 6.3 (NPWS) and, where necessary, Appropriate Assessment as per Article of the Habitats Directive. 6.3 of the Habitats Directive.  Chapter 23 Cumulative (Formerly  Consultation with the relevant Local Authorities is Impacts and Department of recommended to determine if there are any projects or plans Environmental Interactions Arts, Heritage which alone or in combination could impact on any Natura 2000 assesses the potential for and the sites. cumulative impacts arising Gaeltacht) from the Proposed Project in association with other developments, and also considers the potential interaction between environmental aspects arising from the Proposed Project.

11.2.2 Local Planning Policy The Fingal Development Plan 2017-2023 (FDP) (FCC 2017) was reviewed. Policies and objectives in relation to green infrastructure are prescribed in Chapter 8 of the FDP and natural heritage in Chapter 9 of the FDP.

The allied Fingal Biodiversity Action Plan 2010-2015 (FCC 2010) is also a key reference document in guiding the conservation of the natural environment in Fingal by providing a template of action for the next 20 years. The Fingal Biodiversity Action Plan 2010-2015 is based on the development of an Ecological Network across the administrative area of Fingal. The Ecological Network is comprised of four elements:

 Core Nature Conservation Sites;  Buffer Zones around the core sites;  Nature Development Areas (NDAs); and  Ecological corridors and stepping stones. The purpose of the Ecological Network is to provide a framework and focus for nature conservation efforts in Fingal. Core sites will be enlarged and protected with buffer zones to create more space for sustaining habitats and healthy populations of protected species. NDAs have been identified to provide opportunities for habitat improvement in the wider countryside and urban landscapes. Core sites and NDAs are connected by ecological corridors and stepping stones, with the objective of creating an interconnected landscape through which wildlife can move freely, and healthy populations of both rare and common species can be maintained.

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Certain objectives of the FDP (FCC 2017) are relevant to this assessment, and have been extracted and listed in Table 11.2.

Table 11.2: Selected Objectives of the Fingal Development Plan 2017-2023 Relevant to Terrestrial and Freshwater Aquatic Biodiversity

Objective Text Where this is addressed in Environmental Impact Assessment Report FDP – Chapter 8: Green Infrastructure (selected objectives) GI22 Require all proposals for large scale development, such as road or The Green Infrastructure Plan is contained in drainage schemes, wind farms, housing estates, industrial parks or the Proposed Project Planning Report shopping centres, to submit a Green Infrastructure Plan as an integral part of a planning application. GI24 Ensure biodiversity conservation and/or enhancement measures, as Section 12.7 of Chapter 12 Landscape and appropriate, are included in all proposals for large scale development Visual outlines the enhancement measures such as road or drainage schemes, wind farms, housing estates, for the Proposed Project, including the industrial parks or shopping centres. planting of a series of flowing organic embankments with dense bands (approx. 15m to 20m wide) of hedgerow tree species and additional tree lines and grids at the proposed WwTP. FDP – Chapter 9: Natural Heritage (selected objectives) NH15 Strictly protect areas designated or proposed to be designated as EIAR Chapter 9 Biodiversity (Marine), Natura 2000 sites (i.e. SACs and SPAs, also known as European Chapter 10 Biodiversity (Marine Ornithology), Sites) including any areas that may be proposed for designation or the NIS and this Chapter describe how the designated during the period of this Plan. Proposed Project adheres with this Policy by avoiding footprints within designated sites, NH16 Protect the ecological integrity of proposed Natural Heritage Areas their buffer zones and locations where (pNHAs), Natural Heritage Areas (NHAs), Statutory Nature Reserves, protected species occur, where this can be Refuges for Fauna, and Habitat Directive Annex I sites. achieved; and describing the predicted NH17 Ensure that development does not have a significant adverse impact impacts upon designated sites, their buffer on pNHAs, NHAs, Statutory Nature Reserves, Refuges for Fauna, zones and protected species, and mitigation Habitat Directive Annex I sites and Annex II species contained measures proposed to reduce impacts on therein, and on rare and threatened species including those protected designated sites, their buffer zones and by law and their habitats. protected species. NH18 Protect the functions of the ecological buffer zones and ensure proposals for development have no significant adverse impact on the habitats and species of interest located therein. NH19 Develop Ecological Masterplans for the Rogerstown, Malahide and Section 11.4 and Section 11.5 describe the Baldoyle Estuaries focusing on their ecological protection and that of predicted impacts upon NDAs, and Section their surrounding buffer zones. 11.8 concludes that likely significant impacts are not predicted upon NDAs. NH20 Maintain and/or enhance the biodiversity of the NDAs indicated on the Green Infrastructure Maps. NH23 Protect the ecological functions and integrity of the corridors indicated Section 11.9 and Section 11.10 describe the on the Development Plan Green Infrastructure Maps. predicted impacts upon these corridors and watercourses, and Section 11.15 concludes NH24 Protect rivers, streams and other watercourses and maintain them in that likely significant impacts are not an open state capable of providing suitable habitat for fauna and flora, predicted upon these corridors and including fish. watercourses. NH25 Provide for public understanding of and public access to rivers, Not applicable waterway corridors and wetlands, where feasible and appropriate, in partnership with the NPWS, Waterways Ireland and other relevant stakeholders, while maintaining them free from inappropriate development and subject to Ecological Impact Assessment and screening for Appropriate Assessment as appropriate. NH27 Protect existing woodlands, trees and hedgerows which are of EIAR Chapter 4 Description of the Proposed amenity or biodiversity value and/or contribute to landscape character Project and Section 11.7 describe how and ensure that proper provision is made for their protection and vegetation to be retained will be protected, management. and how vegetation to be lost will be replaced.

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Objective Text Where this is addressed in Environmental Impact Assessment Report NH50 Protect and enhance the special landscape character and exceptional Not applicable landscape value of the islands, including their biodiversity, archaeological and architectural heritage. NH60 Strictly control the nature and pattern of development within coastal EIAR Chapter 8 Marine Water Quality, areas and ensure that it is designed and landscaped to the highest Chapter 9 Biodiversity (Marine), Chapter 10 standards, and sited appropriately so as not to detract from the visual Biodiversity (Marine Ornithology), Chapter 12 amenity of the area. Development shall be prohibited where the Landscape and Visual and this Chapter development poses a significant or potential threat to coastal habitats describe how the Proposed Project adheres or features, and/or where the development is likely to result in altered with this Policy as it does not give rise to patterns of erosion or deposition elsewhere along the coast. significant environmental impacts, including visual impacts upon coastal habitats or features, and does not result in altered patterns of erosion or deposition elsewhere along the coast.

11.2.3 Field Survey Terrestrial Habitats

An extended Phase 1 Habitat Survey was conducted along and extending 50m around each component of the Proposed Project over three years (July and August 2012; March and September 2013; April, May and August 2015), and re-surveyed again in August 2017. Such an approach facilitates the optimal survey season in which to survey the broad habitats and characteristic flora expected to be present within the footprint of the Proposed Project. The survey corridor broadly comprises grassland, woodland and scrub habitats and would not be impacted by construction or drilling techniques required for the Proposed Project beyond a 50m distance.

Surveys were coordinated and conducted by a team of competent and professional ecologists with considerable experience of habitat survey techniques in Ireland. The surveys were undertaken in accordance with the Heritage Council’s (2011) Best Practice Guidance for Habitat Survey and Mapping. All terrestrial habitats (i.e. above the mean high-water mark) were mapped, and an intensive search was undertaken for protected and invasive flora species. Habitat assessment categories used were consistent with those outlined in A Guide to Habitats in Ireland (Fossitt 2000). A botanical quadrat survey was conducted at the site of proposed temporary construction compound no.10 due to the possibility of Annex I dune habitats occurring there (refer to Appendix A11.2).

Bats

Bat surveys for the Proposed Project were undertaken by experienced and licenced bat surveyors between 2012 and 2017. Preliminary walkover surveys extending 50m around each component of the Proposed Project were undertaken in June and August 2012, and September and October 2013, and habitats and structures of potential value to bats were noted and marked on a map. The value of each feature was noted according to its potential for use by bats for roosting, foraging or commuting. The value of habitat features for bats was defined in accordance with Bat Surveys for Professional Ecologists: Good Practice Guidelines (Collins 2016) as shown in Table 11.3. Both dusk activity surveys (from sunset, for a minimum of 120 minutes) and dawn activity surveys (from a minimum of 90 minutes prior to sunrise) were initially undertaken in 2012 and supplemented in 2013, 2015 and 2017. Dates of surveys are included in Appendix A11.1. These surveys enabled the identification of any obvious roost sites, determined the approximate numbers and species of bats present within the Proposed Project study area (as defined in Section 11.1.2), areas used for foraging, commuting routes to and from roosts and any changes in mid to late summer activity levels. The approximate flying height and direction

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taken by bats were estimated and detailed where possible. Handheld detectors were used while walking along transects within the study area (as illustrated in Appendix A11.1, Figure 2.1 and Figure 2.2), and a driven transect was conducted in order to cover greater portions of the study area than on foot. Specific dusk emergence and dawn re-entry surveys were undertaken of trees that were identified during the activity surveys as obvious potential roosting sites (from approximately 15 minutes before sunset for a minimum of 120 minutes and from a minimum of 90 minutes prior to sunrise respectively). All surveys were conducted in optimum weather conditions (avoiding periods of very heavy rain, strong winds (i.e. greater than Beaufort Force 5), mists and dusk temperatures below 10°C).

In order to supplement the information gathered from the manual activity surveys, a Passive Monitoring System of bat detection was also deployed at point locations within the Proposed Project boundary (as illustrated in Appendix A11.1, Figure A.1 and Figure A.2) in 2017. A bat detector is left in the field, there is no observer present and bats which pass near enough to the monitoring unit are recorded and their calls are stored for later analysis. The bat detector is effectively used as a bat activity data logger. This results in a far greater sampling effort over a shorter period of time, and also has the advantage that the detector can be positioned in locations that could not be walked in the hours of darkness for health and safety reasons. Passive monitoring was completed using an Anabat Express static detector. Bats were identified by their ultrasonic calls. This detector system recorded bat ultrasonic calls on a continuous basis and stored the information onto an internal Secure Digital (SD) card. Each time a bat was detected, an individual time- stamped (date and time to the second) file was recorded. One Anabat Express monitor was deployed for the survey and was positioned in eight different locations, as illustrated in the Bat Survey Report in Appendix A11.1. The Anabat Express monitor was positioned in hedgerows, treelines and woodland that will be severed by, or are adjacent to, the Proposed Project, primarily in locations that could not be accessed at night-time. The detector was set to record from approximately 30 minutes before sunset until sunrise. Data were then downloaded and bat echolocation calls were later analysed by an AnalookW software analysis programme. Each time-stamped file was analysed and the species of bat recorded was noted as a bat pass.

Table 11.3: Value of Habitat Features for Bats (Collins 2016)

Suitability Description

Roosting Habitats Commuting and Foraging Habitats Negligible Negligible habitat features on-site likely to be used by Negligible habitat features on-site likely to be used by roosting bats. commuting or foraging bats. Low A structure with one or more potential roost sites that Habitat that could be used by small numbers of could be used by individual bats opportunistically. commuting bats such as gappy hedgerow or un- However, these potential roost sites do not provide vegetated stream, but isolated, i.e. not very well enough space, shelter, protection, appropriate conditions connected to the surrounding landscape by other habitat. and/or suitable surrounding habitat to be used on a Suitable, but isolated, habitat that could be used by small regular basis or by larger numbers of bats (i.e. unlikely to numbers of foraging bats, such as a lone tree (not in a be suitable for maternity or hibernation). parkland situation) or a patch of scrub. A tree of sufficient size and age to contain Potential Roost Features (PRFs), but with no features seen from the ground or features seen with only very limited roosting potential. Moderate A structure or tree with one or more potential roost sites Continuous habitat connected to the wider landscape that could be used by bats due to their size, shelter, that could be used by bats for commuting such as lines protection, conditions and surrounding habitat but of trees and scrub or linked back gardens. unlikely to support a roost of high conservation status. Habitat that is connected to the wider landscape that (With respect to roost type only, the assessments in this could be used by bats for foraging such as trees, scrub, table are made irrespective of species conservation grassland or water. status, which is established after presence is confirmed).

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Suitability Description

Roosting Habitats Commuting and Foraging Habitats High A structure or tree with one or more potential roost sites Continuous, high quality habitat that is well connected to that are obviously suitable for use by larger numbers of the wider landscape that is likely to be used regularly by bats on a more regular basis and potentially for longer commuting bats such as river valleys, streams, periods of time due to their size, shelter, protection, hedgerows, lines of trees and woodland edge. conditions and surrounding habitat. High quality habitat that is well connected to the wider landscape that is likely to be used regularly by foraging bats such as broadleaved woodland, tree-lined watercourses and grazed parkland. Site is close to and connected to known roosts.

Mammals (Other than Bats)

Upon review of the results of the extended Phase 1 Habitat Survey, a badger and otter survey was conducted along and extending 100m around each component of the Proposed Project between November 2012 and February 2013 (winter 2012/2013), and repeated again twice: once in winter 2015/2016 and again in August/September 2017. The freshwater aquatic ecology surveys undertaken in 2012, 2015 and 2017 (see Section 11.9.1) also examined watercourses and their bankside vegetation for signs of otter activity.

Badger and otter surveys were conducted in accordance with the National Road Authority (NRA) (now Transport Infrastructure Ireland) Ecological Surveying Techniques for Protected Flora and Fauna during the Planning of National Road Schemes (NRA 2009a) as this provides best practice methodologies for major infrastructure projects. It is the view of the authors that ground mammals would not likely be significantly affected by the construction or operation of elements of the Proposed Project, including underground drilling, beyond 100m. Disturbance to protected ground mammals occurs when they change behaviour in response to noise or visual stimuli. The focus of the assessment on badgers and otters is to establish whether or not they use the land in a given area; and whether or not the resting place of any badger or otter occurs within a given area. Disturbance licences can be required up to 100m away from certain activities, and this is deemed to be the point beyond which likely significant impacts will not occur.

The objectives of the badger survey were to:

 Confirm whether or not badger setts occur within the Proposed Project study area surveyed;  Confirm where possible the status of any setts identified in survey; and  Describe field signs of badger activity. Notes were made on signs of mammals in order to deduce the likelihood of faint tracks and/or feeding signs belonging to badgers. The objective of the otter survey was to identify and describe:

 Sleeping and resting places, including holts, couches and natal dens;  Breeding sites;  Spraints;  Pathways/trails;  Slides;  Hairs;  Footprints; and  Food remains.

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Farmland Birds The bird species and designations related to the estuarine and nearshore habitats of Baldoyle Bay are covered in Chapter 10 Biodiversity (Marine Ornithology) of this EIAR. This Chapter deals with land based species, largely comprising the species frequently referred to under the broad term ‘farmland birds’, but also including all raptors and inland riverine species such as kingfisher. The following ornithological elements of this Chapter therefore only consider these birds and their habitats.

The terrestrial footprint of the Proposed Project occupies open fields, with agriculture the main land use pattern. Habitats are heavily modified, with very few natural or semi-natural features. As a result, and taking account of the extended Phase 1 Habitat Survey, methods appropriate to lowland agricultural landscapes were adopted to survey both breeding and wintering birds, to determine the species present and their distribution. Given the nature of the landscape, particular consideration was given to the identification of any locations and habitats that supported higher relative concentrations of target species, so impacts on these species could be assessed, and any mitigation devised accordingly. Detailed surveys were carried out to confirm the baseline, and in particular to check for any unexpected species of conservation importance or concentrations of other species that would need to be assessed.

Breeding Farmland Birds

In order to establish the breeding bird assemblage in the Proposed Project survey area, surveys were completed for the proposed WwTP in 2012, 2013, 2015 and 2017 and along the entire Proposed Project in 2015 and 2017. Breeding bird surveys of the proposed WwTP were carried out in June 2012, April and June 2013, and repeated again between April and July in 2015 and 2017 using an abridged version of the British Trust for Ornithology’s (BTO’s) Common Bird Census Technique (Bibby et al. 2000; Gilbert et al. 1998), which aims to capture data on breeding bird activity within the survey area surrounding the proposed WwTP during the optimal survey window (April to July).

For the breeding bird survey of the Proposed Project, the survey extended 250m around each component of the Proposed Project. Unlike ground mammals, breeding farmland birds can be much more vulnerable to elevated noise levels which can mask their song. A survey area extending to 250m was selected to ensure that any breeding territories of sensitive songbirds which might be impacted by the Construction Phase or Operational Phase of the Proposed Project would be recorded if present.

All bird species encountered during the survey were mapped and coded using standard BTO species codes and categories of breeding evidence, e.g. singing male, carrying food, recently fledged downy young. No attempts were made to locate nests, as such behaviours are generally sufficient to determine probable or confirmed breeding. Survey visits commenced shortly after dawn and were generally completed before mid- day to coincide with the peak bird activity period. Visits were not made during adverse weather conditions. A transect route was chosen to ensure all elements of the Proposed Project survey area were passed within 50m.

Minor and localised restrictions in the survey study area did not affect the robust assessment conducted. In 2015, two sets of surveys were carried out (in late April and June), with repeat surveys also completed in 2017 (May and June). The surveys focused on areas of potential ornithological interest, such as waterbodies, drainage ditches, watercourses, scrub and woodland edges. The location and activities of all species seen or heard were recorded on field maps using standard BTO species codes and activity symbols, including behaviour and flight lines of the birds. Where possible, the sex of individuals was identified, and whether the bird was an individual or one of a pair. Account was also taken of whether birds were new or previously

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recorded birds that had moved position. Surveys were carried out in suitable weather conditions to ensure good visibility.

Wintering Farmland Birds

For the winter bird survey of the Proposed Project, the survey extended 250m around each component of the Proposed Project using the same method as above, i.e. BTO Common Bird Census Technique, to capture a snapshot of wintering bird activity within a site. The proposed pipeline routes were divided into 10 sectors and bird numbers were recorded for each sector, mapping the location and activities of all bird species seen, with sightings recorded on field maps using standard BTO species codes and activity symbols, including behaviour and flight lines of the birds. Three sets of visits were carried out, in late winter 2014/2015, in early winter 2015/2016 and in late winter 2016/2017. The same approach was used as for the breeding bird survey, i.e. surveyors walked the route, pausing at appropriate points to focus on areas of potential ornithological interest such as waterbodies, watercourses, scrub, hedges and woodland edges, stubble fields and game cover crops. All surveys were conducted by competent and professional ornithologists with considerable experience of bird survey techniques in Ireland.

Other Species Groups Newt Survey

Upon review of the results of extended Phase 1 Habitat Survey, it was considered that none of the ditches along the proposed pipeline routes or at the proposed WwTP site were suitable for smooth newts. Three locations along the proposed pipeline routes were identified as waterbodies holding potential for smooth newt breeding sites, as illustrated in Figure 1 of Appendix A11.3. A smooth newt survey was conducted under licence within 250m of the Proposed Project footprint at these three locations. The survey included 16 ponds and was conducted in May and June 2015. This survey was repeated at the same three locations in May and June 2017. The methodology used followed survey techniques for smooth newts, as outlined in Ecological Survey Techniques for Protected Flora and Fauna (NRA 2009a) and the guidance issued by the Northern Ireland Environment Agency (NIEA) Newt Surveys – NIEA Specific Requirements (NIEA 2014). Additional guidance was gathered from Britain’s Reptiles Amphibians (Inns 2009), The distribution and status of smooth newts in Northern Ireland (O’Neill et al. 2004) and the IWT National Smooth Newt Survey 2013 Report (Meehan 2013)

Smooth newt survey results are presented in Appendix A11.3. During each survey visit, a two-pronged survey approach was employed and included (a) dip-netting and (b) torchlight surveys. Dip-netting was followed by torchlight survey during the hours of darkness. The two-pronged approach aims to identify and record newts within waterbodies, typically to observe individuals swimming to the surface to take gulps of air. Torchlight surveys were undertaken using rechargeable torches rated at 1 million candlepower. Dip-netting could not be undertaken at all pools, and drainage ditches were deemed too shallow or too densely vegetated.

Freshwater Habitat Assessment

The freshwater flora and fauna assessment addresses fishery value, invertebrate fauna, aquatic flora, water quality, habitat value and general ecological condition of freshwater catchments and their streams/rivers near or intersected by the Proposed Project and provides baseline data against which future changes can be assessed. It also assesses the general status of the potentially affected watercourses from an ecological and fisheries perspective in the context of downstream catchments, coastal SACs and SPAs from a freshwater ecology point of view.

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Habitat assessments upstream and for 1km downstream (where possible) of each of the freshwater sampling locations (see Figure 11.17 Freshwater Sampling Locations) were carried out in July 2012 and June 2015. Repeat habitat surveys at each surveyed location were carried out in June 2017. Each river reach (uninterrupted length of river) was assessed using the following criteria:

 Watercourse width and depth;  Substrate type, listing substrate fractions (e.g. bedrock, boulders, cobble, pebbles, gravel, sand and silt) in order of dominance (e.g. dominant, common);  Flow type, listing percentage of riffle, glide and pool in the sampling area;  In-stream vegetation, listing plant species occurring and their percentage coverage of the stream bottom at the sampling location;  Dominant bankside vegetation, listing the main species overhanging the stream and present in the riparian zone;  Estimated degree of shade of the sampling site by bankside vegetation; and  The degree of siltation was recorded on a scale of clean, slight, moderate and heavy, prior to kick sampling. Surveys were carried out at each of the watercourses within the optimum period to conduct macroinvertebrate and in-stream flora assessments, i.e. between the months of May and September, as light and river conditions are generally more suitable and diversity is greatest. Protected Freshwater Species

Criteria used for Assessment of Salmonid Habitat Quality

Each stream habitat section was rated as habitat for the different life stages of salmonid fish based on the habitat assessment features listed above.

Habitat quality for in-stream macroinvertebrates, plant communities, fish, and riparian birds and mammals is primarily a function of 'naturalness' and diversity. The more diverse the stream habitat, in terms of substrate, flow rate, depth, riparian vegetation and light conditions, the richer the biological community is likely to be, and the more suitable it is likely to be for salmonid fish (trout (Salmo trutta) and Atlantic salmon (Salmo salar)).

Assessment of the quality of salmonid spawning, nursery and adult habitats is based on professional expertise and judgement, and published information such as the following:

 Favourable locations for salmon spawning are likely to occur where the gradient of a river is 3% or less (Mills 1989);  Preferred current velocity for spawning is within the range 25–90cm/s, with a water depth in the range 17–76cm (Hendry and Cragg-Hine 1997);  Typical spawning sites are the transitional areas between pool and riffle where flow is accelerating and depth decreasing, where gravel of suitable coarseness is present and interstices are kept clean by up- welling flow (Bjornn and Reiser 1991);  Salmon fry and parr occupy shallow, fast-flowing water with a moderately coarse substrate with cover (Symons and Heland 1978, Baglinière and Champigneulle 1986);  Deep or slow-moving water, particularly when associated with a sand or silt substrate, does not support resident juvenile salmonids (Baglinière and Champigneulle 1986);  Suitable cover for juveniles includes areas of deep water, surface turbulence, loose substrate, large rocks and other submerged obstructions, undercut banks, overhanging vegetation, woody debris lodged in the channel, and aquatic vegetation (Heggenes 1990, Bjorn and Reiser 1991, Haury et al. 1995);

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 The juxtaposition of habitat types is also important. The proximity of juvenile habitat to spawning gravels may be significant to their utilisation. In addition, adults require holding pools immediately downstream of spawning gravels in which they can congregate prior to spawning. Cover for adult salmon waiting to migrate or spawn can be provided by overhanging vegetation, undercut banks, submerged vegetation, submerged objects such as logs and rocks, floating debris, deep water and surface turbulence (Bjorn and Reiser 1991); and  Proximity of cover to spawning areas may be a factor in the selection of spawning sites by some salmonid species (Bjorn and Reiser 1991). Criteria used for Assessment of Lamprey Habitat Quality

Lamprey habitat preferences change with the stages of their life cycle. They show a preference for gravel- dominated substratum for spawning. After hatching, the larvae swim or are washed downstream by the current to areas of sandy silt in still or slow-flowing water where they burrow and spend the next few years in tunnels. Lampreys therefore require mainly silt- and sand-dominated substratum for nursery habitat. Other important environmental characteristics for optimal ammocoete (juvenile) habitat are shallow waters with low water velocity, and the presence of organic detritus and/or plant material. Sub-optimal habitat supporting only a few individuals may consist of a few square centimetres of suitable silt in an open, comparatively high- velocity, boulder-strewn streambed. Spate rivers with high flow velocities tend to support fewer ammocoetes, as they contain smaller areas of stable sediment (Maitland 2003). Criteria used for Assessment of White-Clawed Crayfish Habitat Quality

White-clawed crayfish (Austropotamobius pallipes) are typically found in watercourses of 0.75m to 1.25m depth, but the species may occur in very shallow streams (about 50mm of water) and in deeper, slow-flowing rivers (2.5m) (Holdich 2003). The white-clawed crayfish typically occupies cryptic habitats under rocks and submerged logs, among tree roots, algae and macrophytes, although it usually emerges to forage for food. Juveniles in particular may also be found among cobbles and detritus such as leaf litter. Adults may burrow into suitable substrates, particularly in the winter months. In habitats with flowing water, the white-clawed crayfish may be found in association with:

 Undermined, overhanging banks;  Sections exhibiting heterogeneous flow patterns with refuges;  Under cobbles (juveniles) and rocks in riffles, and under larger rocks in pools;  Among roots of woody vegetation, accumulations of fallen leaves and boulder weirs; and  Under water-saturated logs (Holdich 2003). Peay (2003) lists the following habitat features as favoured by crayfish:

 Slow-flowing glides and pools (provided there are refuges), localised velocity of 0.1m/s or less;  Loose boulders (>250mm) or other similarly sized material;  Boulders or large cobbles in groups with crevices between them;  Deep crevices in bedrock;  Underlying substrate of fine gravel/sand with some pebbles;  Submerged refuges in stable banks (e.g. natural crevices, stone block reinforcement or stable, slightly undercut banks with overhanging vegetation, large tree roots);  Un-mortared stone revetting which protects banks from erosion; and  Stands of submerged and emergent aquatic plants.

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The rating of the sections as habitat for these protected species (salmonids, lamprey and crayfish) is on a scale of None/Poor/Fair/Good/Very Good/Excellent. This rating assesses the physical suitability of the habitat; the presence/absence/density of the species in question will also depend on present and historical water quality and accessibility of the section to these species. A rating of ‘None’ indicates that the ecologist carrying out the assessment regards it as impossible that the watercourse could support the species in question in the relevant life stage.

A rating of ‘None – Poor’ indicates that it is regarded as possible but extremely unlikely that the stream could support the species in the relevant life stage. ‘Fair’ indicates that it is possible that the stream section could support the species in question. ‘Good’ indicates that the ecologist considerers it possible and likely that the stream could support the species in question. ‘Very Good’ indicates that the stream certainly could support the species. ‘Excellent’ indicates that the ecologist regards the stream as the ideal habitat for the species in question.

Other Freshwater Taxa Macroinvertebrate Diversity and Biological Water Quality Assessment

Field surveys were carried out during July 2012, June 2015 and June 2017 following the EPA methodology for biological surveillance and water quality assessment of rivers (Toner et al. 2005). A two-minute kick and stone wash sample was taken at each of the freshwater sampling locations. Each of the samples was live sorted for a period of 30 minutes in situ. Relative abundance and sensitivity to organic pollution is used to indicate the water quality of the sampled watercourses. Relative abundance is determined by the percentage of the abundance each taxon represents (Table 11.4).

Table 11.4: Relative Abundance Categories Relative Abundance Category Approximate Percentage of Community

Present 1 or 2 individuals Scarce/Few <1% Small numbers <5% Fair numbers 5–10% Common 10–20% Numerous 20–50% Dominant 50–75% Excessive >75%

Q-values and water quality classes are assigned using a combination of habitat characteristics and structure of the macroinvertebrate community within the waterbody. EPA indices, EPA water quality status and WFD status are interpreted in Table 11.5.

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Table 11.5: Environmental Protection Agency Q Rating and Equivalent Water Framework Directive Water Quality Status Classes (Colour Coding as Employed under Water Framework Directive as Specified in Schedule 3 of European Communities Environmental Objectives (Surface Waters) Regulations 2009 (S.I. No 272 of 2009) (as amended)) Environmental Water Framework Biotic Index Environmental Quality Ratio Protection Agency Water Quality Directive Status Quality Status

Q5 1.0 Unpolluted Good High Q4-5 0.9 Unpolluted Fair to Good High Q4 0.8 Unpolluted Fair Good Q3-4 0.7 Slightly Polluted Doubtful to Fair Moderate Q3 0.6 Moderately Polluted Doubtful Poor Q2-3 0.5 Moderately Polluted Poor to Doubtful Poor Q2 0.4 Seriously Polluted Poor Bad Q1-2 0.3 Seriously Polluted Bad to Poor Bad Q1 0.2 Seriously Polluted Bad Bad Note: High – Blue, Good – Green, Moderate – Yellow, Poor – Orange, and Bad – Red) The Environmental Quality Ratio represents the relationship between the values of the biological parameters observed for a given body of surface water and the values for these parameters in the reference conditions applicable to that body. The ratio is expressed as a numerical value between zero and one, with high ecological status represented by values close to one and bad ecological status by values close to zero. In Ireland, it is calculated as Observed Q-value/Reference Q-value (e.g. Q5). The Environmental Quality Ratio allows comparison of water quality status across the European Union, as each member state has an Environmental Quality Ratio value for ‘High’; ‘Good’, ‘Moderate’, ‘Poor’ and ‘Bad’, based on an intercalibration of boundaries between water quality categories e.g., ‘High–Good’; ‘Good–Moderate’.

Freshwater Flora Assessment

In-stream vegetation was assessed during June 2015 and June 2017 at each of the biological sampling locations. Plant species occurring were listed, and their percentage coverage of the stream bottom at the sampling site was estimated.

11.2.4 Valuation and Impact Assessment The information gathered from non-statutory informal consultations, scoping, stakeholder feedback, the desk study and the suite of targeted ecological field surveys has been used to inform the assessment of the Proposed Project. The impact assessment has been undertaken following the methodology set out in:

 Guidelines for Ecological Impact Assessment in the UK and Ireland: Terrestrial, Freshwater and Coastal (Chartered Institute of Ecology and Environmental Management (CIEEM) 2016);  Guidelines for Assessment of Ecological Impacts of National Road Schemes Revision 2 (NRA 2009b);  Draft Guidelines on the Information to be Contained in Environmental Impact Assessment Reports (EPA 2017); and  BS 42020:2013 Biodiversity: Code of practice for planning and development (British Standards Institution 2013). The impact assessment is based upon a source-pathway-receptor model, where the source is defined as the individual elements of the Proposed Project that have the potential to affect identified ecological features. The pathway is defined as the means or route by which a source can affect the ecological features. An ecological receptor is the feature of interest, being a species, habitat or ecologically functioning unit of natural heritage

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importance. Each element can exist independently; however, an effect is created where there is a linkage between the source, pathway and feature. A significant effect is defined in the CIEEM (2016) guidelines as:

‘an effect that either supports or undermines biodiversity conservation objectives for ‘important ecological features’ [...] or for biodiversity in general. Conservation objectives may be specific (e.g. for a designated site) or broad (e.g. national/local nature conservation policy) or more wide-ranging (enhancement of biodiversity). Effects can be considered significant at a wide range of scales from international to local’; and ‘an effect that is sufficiently important to require assessment and reporting so that the decision maker is adequately informed of the environmental consequences of permitting a project. A significant effect is a positive or negative ecological effect that should be given weight in judging whether to authorise a project: it can influence whether permission is given or refused and, if given, whether the effect is important enough to warrant conditions, restrictions or further requirements such as monitoring’.

BS 42020:2013 states that if an effect is sufficiently important to be given weight in the planning balance or to warrant the imposition of a planning condition, e.g. to provide or guarantee necessary mitigation measures, it is likely to be ‘significant’ in that context at the level under consideration. The converse is also true: insignificant impacts would not warrant a refusal of permission or the imposition of conditions. Likely significant impacts are predicted on the basis of the Proposed Project as described in Chapter 4 Description of the Proposed Project.

Table 11.6 sets out a geographic frame of reference and criteria for valuing ecological features based on the Guidelines for Assessment of Ecological Impacts of National Road Schemes Revision 2 (NRA 2009b) which informs the assessment of the magnitude of impacts. Table 11.7 sets out criteria for predicting magnitudes of effect. The ecological importance of natural resources such as surface waters (freshwaters) and terrestrial habitats has been evaluated against these criteria for the Proposed Project.

The methodology for the assessment of impacts which has been employed for this Chapter is derived from and uses the terminology of Section 5 of the CIEEM (2016) guidelines, while also incorporating the principles outlined in Section 3.7 of the EPA (2017) guidelines. The impact assessment identifies and characterises impacts and assesses these impacts in the absence of mitigation in the first instance. Following the identification of measures to avoid or mitigate these impacts, an assessment of the significance of any residual impacts after mitigation is presented. The CIEEM (2016) guidelines also state that the impact assessment process should also identify opportunities for ecological enhancement where they arise within developments.

The CIEEM (2016) guidelines are complementary to the EPA (2017) guidelines when describing the nature of effects on biodiversity features:

 Positive or negative: Positive and negative impacts are determined according to whether the change is in accordance with nature conservation objectives and policy, e.g. improves the quality of the environment or reduces the quality of the environment - Quality of Effects (EPA 2017);  Extent: The spatial or geographical area over which the impact/effect may occur (Extent and Context of Effects) (EPA 2017);  Magnitude: ‘Magnitude’ refers to size, amount, intensity and volume. It should be quantified if possible and expressed in absolute or relative terms - Duration and Frequency of Effects (EPA 2017);  Duration: ‘Duration’ is defined in relation to ecological characteristics as well as human timeframes. Five years, which might seem short-term in the human context or that of other long-lived species, would span at least five generations of some invertebrate species. The duration of an activity may differ from the

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duration of the resulting effect caused by the activity. Effects may be described as short, medium or long- term and permanent or temporary. Short, medium, long-term and temporary will need to be defined in months/years - Duration and Frequency of Effects (EPA 2017);  Frequency and timing: The number of times an activity occurs will influence the resulting effect. The timing of an activity or change may result in an impact if it coincides with critical life-stages or seasons - Duration and Frequency of Effects (EPA 2017), and  Reversibility: An irreversible effect is one from which recovery is not possible within a reasonable timescale or there is no reasonable chance of action being taken to reverse it. A reversible effect is one from which spontaneous recovery is possible or which may be counteracted by mitigation. In some cases, the same activity can cause both reversible and irreversible impacts - Duration and Frequency of Effects (EPA 2017).

Table 11.6: Ecological Valuation Criteria for Ecological Biodiversity Features

Ecological Valuation: Examples

International importance:  ‘European Site’, including SACs and candidate SACs, Sites of Community Importance, SPAs or proposed SPAs (pSPAs).  Site that fulfils the criteria for designation as a ‘European Site’.  Features essential to maintaining the coherence of the Natura 2000 Network.  Site containing ‘best examples’ of the habitat types listed in Annex I of the Habitats Directive.  Resident or regularly occurring populations (assessed to be important at the national level) of species of animal and plants listed in Annex II and/or IV of the Habitats Directive.  Ramsar Site (Convention for the Protection of World Cultural & Natural Heritage, 1972).  Biosphere Reserve (UNESCO Man & The Biosphere Programme).  Site hosting significant species populations under the Bonn Convention (Convention on the Conservation of European Wildlife and Natural Habitats, 1979).  Sites hosting significant populations under the Berne Convention (Convention on the Conservation of European Wildlife and Natural Habitats, 1979).  Biogenetic Reserve under the Council of Europe.  European Diploma Site under the Council of Europe.  Salmonid water designated pursuant to the European Communities (Quality of Salmonid Waters) Regulations 1988 (S.I. No. 293 of 1988). National importance:  Site designated or proposed as an NHA/pNHA.  Statutory Nature Reserve.  Refuge for Fauna and Flora protected under the Wildlife Acts 1976-2012.  National Park.  Undesignated site fulfilling the criteria for designation as an NHA; a Statutory Nature Reserve; a Refuge for Fauna and Flora protected under the Wildlife Acts 1976-2012; and/or a National Park.  Resident or regularly occurring populations (assessed to be important at the national level) of species protected under the Wildlife Acts; and/or species listed on the relevant Red Data list.  Site containing ‘viable areas’ of the habitat types listed in Annex I of the Habitats Directive. County importance:  Area of Special Amenity.  Area subject to a Tree Preservation Order.  Area of High Amenity, or equivalent, designated under the County Development Plan (CDP).  Resident or regularly occurring populations (assessed to be important at the county level) of the following: species of bird, listed in Annex I and/or referred to in Article 4(2) of the Birds Directive; species of animal and plants listed in Annex II and/or IV of the Habitats Directive; species protected under the Wildlife Acts; and/or species listed on the relevant Red Data list.  Site containing area or areas of the habitat types listed in Annex I of the Habitats Directive that do not fulfil the criteria for valuation as of International or national importance.  County important populations of species or viable areas of semi-natural habitats or natural heritage features identified in the National or Local Biodiversity Action Plan (BAP), if this has been prepared.  Sites containing semi-natural habitat types with high biodiversity in a county context and a high degree of naturalness, or populations of species that are uncommon within the county.  Sites containing habitats and species that are rare or are undergoing a decline in quality or extent at a national level. Local importance (higher value):  Locally important populations of priority species or habitats or natural heritage features identified in the Local BAP, if this has been prepared.  Resident or regularly occurring populations (assessed to be important at the local level) of the following: species of bird, listed in Annex I and/or referred to in Article 4(2) of the Birds Directive; species of animal and plants listed in Annex II and/or IV of the Habitats Directive; species protected under the Wildlife Acts; and/or species listed on the relevant Red Data list.

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Ecological Valuation: Examples

 Sites containing semi-natural habitat types with high biodiversity in a local context and a high degree of naturalness, or populations of species that are uncommon in the locality.  Sites or features containing common or lower value habitats, including naturalised species that are nevertheless essential in maintaining links and ecological corridors between features of higher ecological value.  Locally important populations of priority species or habitats or features of natural heritage importance identified in a BAP, if this has been prepared.  Key features of local value, being sites or features containing common or lower value habitats that maintain links and function as ecological corridors between key features of local value. Local importance (lower value):  Sites containing small areas of semi-natural habitats that are of limited local importance for wildlife.  Sites containing areas of highly modified habitats.  Sites containing local populations of species that are common and not of conservation value.  Sites that are used by protected species or species of conservation value as part of their territories but which do not contain the breeding or resting places of these species.  Sites that do not maintain links or do not function as ecological corridors between key features of local value.

Table 11.7: Magnitudes of Effect upon Biodiversity Features

Magnitude of Effect Criteria

Major adverse  Adverse effect on the integrity of a European Site  Loss of or permanent damage to any part of a site of international or national importance  Loss of a key component or key feature of a site of county importance  Decline in favourable conservation status or condition of a legally protected species of county value  Causing of an offence under European Directives or domestic transposing legislation Moderate adverse  Temporary or short-term impacts to key features of a site of international or national importance, but no permanent damage or loss of favourable conservation status or condition  Medium to long-term or permanent impacts to any part of a site of county value  Medium to long-term or permanent loss of a key feature of local importance (higher value) where a feature is important for and supports other features  Causing of an offence under domestic legislation Minor adverse  Temporary or short-term impacts to any part of a site of county value  Temporary or short-term loss of a feature of local importance (higher value)  Medium to long-term or permanent loss of a feature of local importance (lower value) Negligible  No impacts above a de minimis threshold on identified biodiversity features  Beneficial and adverse impacts balance such that the resulting impact has no overall affect upon feature Minor beneficial  A small but clear and measurable gain in general wildlife interest, e.g. small-scale new habitats of wildlife value created where none existed before or where the new habitats exceed the area of habitats lost Moderate beneficial  New larger scale habitats (e.g. net gains >1ha in area) created leading to significant measurable gains, helping to achieve relevant objectives of a BAP or CDP Major beneficial  Major gains in new habitats (net gains >10ha) of high significance for biodiversity, helping to achieve relevant objectives of a BAP or CDP and underpinning government policy

11.2.5 Compliance with the Water Framework Directive The potential for the Proposed Project to impact upon water quality is assessed in the context of the WFD. The WFD established a framework for the management of water resources throughout the European Union. The WFD’s overarching goal is to achieve at least good ecological status and good chemical status for all surface waters by 2015, or by 2021/2027 via extended deadlines. The WFD aims are specified in Article 1:

 Prevent further deterioration and protect and enhance the status of aquatic ecosystems and associated wetlands;  Promote the sustainable consumption of water;  Reduce pollution of waters from priority substances and phasing out of priority hazardous substances;  Prevent the deterioration in the status and to progressively reduce pollution of groundwater; and  Contribute to mitigating the impacts of floods and droughts.

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The WFD established four core environmental objectives to be achieved for surface waters which include rivers, lakes, transitional and coastal waters (out to one nautical mile):

 Prevent deterioration;  Protect, enhance and restore Good status by 2015;  Protect and enhance artificial and heavily modified water bodies (aim to achieve Good Ecological Potential and good surface water chemical status); and  Progressively reducing pollution from priority substances and ceasing or phasing out emissions, discharges and losses of priority hazardous substances. In addition, the WFD requires achievement of compliance with any standards and objectives for protected areas set by other legislation, e.g. designated under the Directive 2006/7/EC of the European Parliament and of the Council of 15 February 2006 concerning the management of bathing water quality and repealing Directive 76/160/EEC (Bathing Water Directive), Directive 2006/113/EC of the European Parliament and of the Council of 12 December 2006 on the quality required of shellfish waters (Shellfish Water Directive), Council Directive 98/83/EC of 3 November 1998 on the quality of water intended for human consumption (Drinking Water Directive), Council Directive 91/271/EEC of 21 May 1991 concerning urban wastewater treatment (Urban Waste Water Treatment Directive) and the Habitats and Birds Directives. The Department of Housing, Planning, Community and Local Government set the environmental objectives for each waterbody, based on the scientific evidence, extensive surface water quality monitoring, and risk characterisation undertaken by the EPA. The European Communities Environmental Objectives (Surface Waters) Regulations 2009 (S.I. No. 272 of 2009) (as amended) place duties on public authorities to promote the requirements of the regulations and requires that sources of pollution be controlled to prevent or limit the input of pollutants. The impact assessment presented in this Chapter has reviewed the outcomes of the monitoring and characterisation processes undertaken by the EPA for the waters within the ZoI of the Proposed Project, and has incorporated the findings into the impact assessment for the Proposed Project.

More stringent requirements may apply to specific water bodies, in particular those within areas designated as SACs or SPAs. Given that all the relevant watercourses (streams and rivers) within the ZoI are not part of any SAC or SPA, but are directly hydrologically connected to the downstream SPAs of North Bull Island and Baldoyle Bay and the SACs of North Dublin Bay and Baldoyle Bay, the impact assessment and mitigation outlined are influenced by these designations. The environmental objective for these waters is good status, as per the Draft River Basin Management Plan for Ireland 2018–2021 (Department of Housing, Planning, Community and Local Government (DoHPLG) 2018).

11.3 Baseline Environment – Terrestrial Flora and Fauna

11.3.1 Designated Sites European Sites

Other than the proposed outfall pipeline route (marine section), the associated proposed temporary construction compounds for microtunnelling and the diffuser, there are no other Proposed Project elements near any European Site.

The proposed outfall pipeline route (marine section) will cross under the estuary habitats of Baldoyle Bay SAC and pNHA [Site Code: 000199] and Baldoyle Bay SPA [Site Code: 004016] and will terminate within the Rockabill to Dalkey Island SAC [Site Code: 003000] approximately 1km north-east of Ireland’s Eye.

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The proposed outfall pipeline route (marine section) will cross under Baldoyle Estuary between proposed temporary construction compound no. 9 and proposed temporary construction compound no. 10, and again will pass under Baldoyle Bay SAC 170m seaward of the top of the beach at Velvet Strand for a distance of approximately 100m. Proposed temporary construction compound no. 10 abuts Baldoyle Bay SAC/SPA/pNHA on its western edge where it meets the Golf Links Road. The Gold Links Road is the boundary of the estuarine SAC/SPA/pNHA.

After passing seaward of Baldoyle Bay SAC for the last time, the proposed outfall pipeline route (marine section) widens out to a 250m wide proposed construction corridor in the marine environment. Approximately 3.2km seaward from the beach at Velvet Strand, the proposed outfall pipeline route (marine section) enters the Rockabill to Dalkey Island SAC [Site Code: 003000], travelling for approximately 1.4km along the seabed in this European Site before ending at the proposed discharge location, approximately 1km north-east of Ireland’s Eye. Where the proposed outfall pipeline route (marine section) enters the Rockabill to Dalkey Island SAC, it passes 140m north of Ireland’s Eye SPA [Site Code: 004117] and 630m north of Ireland’s Eye SAC [Site Code: 002193]. The proposed outfall pipeline route (marine section) will terminate at a discharge point 440m north-east of Ireland’s Eye SPA. European Sites are shown in Figure 11.1 Special Areas of Conservation and Figure 11.2 Special Protection Areas and Ramsar Sites. These European Sites are discussed in greater depth in Chapter 9 Biodiversity (Marine) and Chapter 10 Biodiversity (Marine Ornithology), as their Qualifying Interests and Special Conservation Interests (SCIs) correspond to marine biodiversity features. Other Designated Areas

Baldoyle Bay is also designated as a pNHA, a Ramsar site and as a core area of the Dublin Bay United Nations Educational, Scientific and Culture Organisation (UNESCO) Biosphere Reserve. Similarly, Ireland’s Eye is a pNHA and also a core area of the Dublin Bay UNESCO Biosphere Reserve. Ramsar sites, NHAs and the Dublin Bay UNESCO Biosphere Reserve are all shown in Figure 11.1 Special Areas of Conservation to Figure 11.4 Dublin Bay UNESCO Biosphere Reserve. The Dublin Bay UNESCO Biosphere Reserve comprises three zones: a core area, a buffer zone and a transitional area. It is approximately 12.5km wide, stretching from Dublin Airport in the west to its seaward termination. The proposed outfall pipeline route (marine section) will terminate at a discharge point which will be located within the Dublin Bay UNESCO Biosphere Reserve. Approximately 14km of the Proposed Project (land based elements) will be located within all three (core, buffer or transitional) areas of the Dublin Bay UNESCO Biosphere Reserve, as illustrated in Figure 11.4 Dublin Bay UNESCO Biosphere Reserve.1 The Proposed Project passes below Baldoyle Bay pNHA. The boundary of Baldoyle Bay pNHA is the same as that of Baldoyle Bay SAC, and it is considered within Chapter 9 Biodiversity (Marine). Santry Demesne pNHA is located 340m south of the proposed orbital sewer route where it flanks the eastbound M50 Motorway verge east of the R108 Road junction (M50 Motorway, Junction 4).

The Royal Canal pNHA is located 350m south of the Proposed Project at Abbotstown near the proposed Abbotstown pumping station site. The Sluice River Marsh pNHA is 910m north of the proposed outfall pipeline route (land based section) where it crosses the Belfast–Dublin railway line.

Feltrim Hill pNHA is located approximately 1.2km north of the proposed outfall pipeline route (land based section) near where it passes through the Teagasc facility at Kinsealy.

1i.e. from where the proposed orbital sewer route is proposed to cross the R132 Swords Road to the proposed outfall pipeline route (marine section) discharge point within the Rockabill to Dalkey Island SAC, and including the proposed WwTP)

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NDAs and Ecological Buffer Zones (EBZs) have been identified in the FDP (FCC 2017) and the Fingal Biodiversity Action Plan 2010-2015 (FCC 2010). The Proposed Project passes through or encroaches into NDAs at (i) the origin of the proposed orbital sewer route in woodland enveloping Connolly Hospital at Abbotstown; and (ii) where the proposed orbital sewer route passes through Silloge Park Golf Club. Proposed compound no.7 and a portion of the proposed outfall pipeline route (land based section) will be located within an EBZ at Mayne.

Proposed temporary construction compound no. 9, west of Baldoyle Bay SPA, is within the ‘Portmarnock South Zoned Lands’. This is an area for which a Local Area Plan has been prepared and adopted. It includes a low intervention landscape approach to the EBZ lands in order to retain the supporting ecological functions this landscape provides to the estuary habitats, including a ‘quiet zone’ for migratory birds and arable crop areas for native bird species.

11.3.2 Terrestrial Habitats This Section should be read with reference to Figure 11.5 Habitat Survey Result and Figure 13.2 Proposed Construction Corridor, Access Routes, Compounds and Crossings. Only habitats above the mean high-water mark are detailed here. Intertidal, sub-tidal and marine habitats below the mean high-water mark are detailed in Chapter 9 Biodiversity (Marine). Freshwater aquatic habitats and species are detailed in Section 11.9 of this Chapter. Summary of Habitats

Table 11.8 lists the habitats which were identified within the Proposed Project boundary. Habitats are those described by A Guide to Habitats in Ireland (Fossitt 2000). Ecological valuation is based upon criteria explained in Section 11.2.4 and set out in Table 11.6.

Table 11.8: Summary of Habitats

Heritage Council Habitat Code Habitat Value

FL8 Other artificial lakes and ponds Local importance (higher value) FW2 Depositing lowland rivers Local importance (higher value) FW4 Drainage ditches Local importance (lower value) GA1 Improved agricultural grassland Local importance (lower value) GA2 Amenity grassland Local importance (lower value) GS1 Dry calcareous or neutral grassland Local importance (higher value) GS2 Dry meadows and grassy verges Local importance (higher value) GS4 Wet grassland Local importance (higher value) WD1 (Mixed) broadleaved woodland Local importance (higher value) WS1 Scrub Local importance (higher value) WS2 Immature woodland Local importance (higher value) WL1 Hedgerows Local importance (higher value) WL2 Treelines Local importance (higher value) ED2 Spoil and bare ground Local importance (lower value) ED3 Recolonising bare ground Local importance (lower value) BC1 Arable crops Local importance (lower value) BC2 Horticultural land Local importance (lower value) BC3 Tilled land Local importance (lower value) BL3 Buildings and artificial surfaces Local importance (lower value)

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Heritage Council Habitat Code Habitat Value CD3 Fixed dunes (managed golf course) Local importance (higher value)

Proposed Wastewater Treatment Plant The proposed WwTP footprint, ancillary Proposed Project elements and proposed temporary construction compound areas associated with the proposed WwTP are illustrated in Figure 13.2 Proposed Construction Corridor, Access Routes, Compounds & Crossings (Sheet 2 of 3) to Figure 13.2 Proposed Construction Corridor, Access Routes, Compounds & Crossings (Sheet 3 of 3). This is an area comprising arable crops (habitat code BC1), horticultural land (BC2), hedgerows (WL1) and a drainage ditch (FW4). These large fields were separated by three managed thin and gappy hedgerows travelling north to south. Common hedgerow species, notably hawthorn (Crataegus monogyna) were dominant. A dense and intact mature hedgerow (with a drainage ditch) extended east to west along the southern boundary of the proposed WwTP site.

Proposed Abbotstown Pumping Station The proposed Abbotstown pumping station, ancillary Proposed Project elements and proposed temporary construction compounds associated with the proposed Abbotstown pumping station are illustrated in Figure 13.2 Proposed Construction Corridor, Access Routes, Compounds & Crossings (Sheet 1 of 3). This area comprises an arable field (BC1) and immature woodland (WS2). Mixed broadleaved woodland (WD1) with mature broadleaved species occurs immediately to the south but outside of the footprint of the proposed Abbotstown pumping station site, and also immediately north-east of the proposed Abbotstown pumping station site. To the north-east, the woodland is noted for its mature ornamental conifers and broadleaved trees including oak (Quercus robur) and beech (Fagus sylvatica). The immature woodland within the Proposed Project boundary occurs within an NDA which includes a southward extension of woodland beyond the Tolka Valley Regional Park. Proposed Orbital Sewer Route – Blanchardstown to Clonshagh

The proposed orbital sewer route, ancillary Proposed Project elements and proposed temporary construction compounds associated with the proposed orbital sewer route are all contained within the Proposed Project boundary as illustrated in Figure 13.2 Proposed Construction Corridor, Access Routes, Compounds & Crossings (Sheet 1 of 3). The first section of the proposed orbital sewer route (chainage 0,000m to 1,000m) will be a gravity sewer drilled under the trees and the habitat. No footprint will occur in the surface. Extensive areas of mixed broadleaved woodland (WD1) were present around Connolly Hospital. Intermittent beech (Fagus sylvatica) grow amid younger sycamore (Acer pseudoplatanus), pine (Pinus sp.) and ash (Fraxinus excelsior). Ivy (Hedera helix), holly (Ilex aquifolium) and pine made much of this woodland particularly shaded, and woodland herbs were extremely patchy. A sizable area of neutral grassland (GS1) also occurs within the hospital grounds. Throughout, it had an unmanaged appearance. This woodland is part of an NDA referred to in the previous Section above. Parkland and scattered trees (WD5) were also found in the Connolly Hospital grounds, but not within the proposed construction corridor of the proposed orbital sewer route. The habitats along the proposed orbital sewer route include depositing lowland rivers (FW2), drainage ditches (FW4), improved agricultural grassland (GA1), wet grassland (GS4), mixed broadleaved woodland (WD1), scrub (WS1), hedgerows (WL1), spoil and bare ground (ED2), arable crops (BC1), tilled land (BC3), other artificial lakes and ponds (FL8), recolonising bare ground (ED3), horticultural land (BC2) and buildings and artificial surfaces (BL3). Species contained in the arable, tilled and improved fields along the proposed orbital sewer route were consistent. The improved fields were species poor, as expected. Typical agricultural grassland species were present such as perennial ryegrasses (Lolium spp.), white clover (Trifolium repens)

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and creeping buttercup (Ranunculus repens). Semi-natural habitats were very intermittent along the proposed orbital sewer route.

As the proposed orbital sewer route passes through the NSC towards Cappoge, it will pass through improved grassland fields. The proposed orbital sewer route will pass through 0.55ha of mixed broadleaved woodland (WD1) at chainage (1,300m to 1,400m) comprising ash, sycamore and beech. Disturbed soils which occurred on the periphery of these fields (recolonising bare ground (ED3)) are seemingly a consequence of recent infrastructure and development works. Only common grass and herb species were evident. Horses grazed most of this available grassland.

Some minor exceptions do occur such as the neutral grassland enclosures at Toberbunny. These are overgrown unmanaged enclosures. An area of recolonising bare ground (ED3) occurred here at the long-stay car park. A small pool and three drainage ditches occurred here and were surveyed for smooth newt in 2015. Smooth newt was not recorded in any of these waterbodies. These ditches had infilled with bulrush (Typha latifolia). Pointed spear-moss (Calliergonella cuspidata), willowherbs (Epilobium sp.) and sedges (Carex spp.) are colonising the gravels.

Drainage ditches (FW4) occurred throughout this section of the route. Many support species were found on upper field margins such as bramble (Rubus fruticosus agg.) and false oat grass (Arrhenatherum elatius). The occurrence of moisture-loving or purely aquatic herbs and forbs was highly variable. Identified species included brooklime (Veronica beccabunga), fool’s watercress (Apium nodiflorum) and floating sweet-grass (Glyceria fluitans). These habitats are useful breeding sites for common frog (Rana temporaria) as well as supporting many aquatic invertebrates.

Hedgerows were comprised mainly of hawthorn, ash (Fraxinus excelsior), occasional beech (Fagus sylvatica), blackthorn (Prunus spinosa) and hazel (Corylus avellana). Proposed Temporary Construction Compound No. 2

Proposed temporary construction compound no.2 at chainage 3,500m to 3,700m will be located along the proposed orbital sewer route, as illustrated in Figure 13.2 Proposed Construction Corridor, Access Routes, Compounds & Crossings (Sheet 1 of 3). Habitats are comprised of two enclosures of improved grassland (GA1) and horticultural land (BC2), with a line of trees and scrub around the site of proposed temporary construction compound no. 2. Improved grassland fields were the dominant habitat travelling towards the N2 National Road. There was an unmanaged wet grassland enclosure at chainage 5,300m just east of the N2 National Road. Common species were present such as glaucous sedge (Carex flacca), sweet vernal grass (Anthoxanthum odoratum), rushes (Juncus spp.) and pointed spear-moss (Calliergonella cuspidata). Creeping thistle (Cirsium arvense) and dandelion (Taraxacum officinale agg.) were frequent. Pioneer oak (Quercus spp.) and willow (Salix spp.) also occurred. This field bordered broadleaved woodland (WD1). Linear woodland occurred between the quarry access roads south of this enclosure.

A large area of recolonising bare ground was present immediately east of the N2 National Road at Coldwinters (chainage 5,600m to 6,100m). The site was entirely comprised of spoil (presumably from road infrastructure works) creating a very uneven hilly terrain. Ponds and pools formed in several hollows and in tracks made from heavy plant, some of which support aquatic plants. Sixteen pools and ponds were identified during the extended Phase 1 Habitat Survey. A macro algae (Chara) species was dominant. Smooth newt (Lissotriton vulgaris) was confirmed present in some of these ponds during smooth newt surveys. A smooth newt survey report is presented as Appendix A11.3. Horses have maintained a very short sward. Flowering

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herbs and grasses include common species like white clover (Trifolium repens), plantains (Plantago spp.) and common ragwort (Senecio jacobaea).

Intensively farmed enclosures (tillage, horticulture and pasture) and amenity grassland were the dominant habitats approaching Ballymun. Proposed Temporary Construction Compound No. 3

Proposed temporary construction compound no. 3 (chainage 8,900m to 9,100m) at Ballymun will be located along the proposed orbital sewer route, as illustrated in Figure 13.2 Proposed Construction Corridor, Access Routes, Compounds & Crossings (Sheet 1 of 3), and the site contains recolonised bare ground (ED3) and neutral grassland (GS1). The grassland was unmanaged and rank in parts. A series of ponds are located in the recolonising bare habitat. They have developed communities of aquatic plants and freshwater invertebrates. The 2015 smooth newt survey did not find any newts at this location.

The recolonising bare ground had an array of flowering herbs, including frequent birdsfoot trefoil (Lotus corniculatus), silverweed (Potentilla anserine), selfheal (Prunella vulgaris), cowslip (Primula veris) and scattered lady's mantle (Alchemilla sp.). A golf course surrounds these habitats to the north and west. Spoil and bare ground (ED2) and scrub (WS1) dominated by butterfly bush (Buddleja davidii) were present nearby. The spoil and bare ground (ED2) and scrub (WS1) habitats occupy the area of proposed temporary construction compound no. 3 on either side of the approach road to a National Car Test Centre.

Travelling east from proposed temporary construction compound no. 3, habitats comprise car parking and other hard standing associated with Dublin Airport and local industry. Intensively farmed lands (GA1) and amenity grasslands (GA2) were the dominant habitats.

Proposed Temporary Construction Compound No. 4

Proposed temporary construction compound no. 4 (11,700m to 11,800m) will be located at the Old Airport Road/R132 Swords Road junction (the Collinstown Crossroads), along the proposed orbital sewer route, as illustrated in Figure 13.2 Proposed Construction Corridor, Access Routes, Compounds & Crossings (Sheet 1 of 3). As with proposed temporary construction compound no. 3, the main habitat here was spoil and bare ground (ED2).

Proposed Outfall Pipeline Route (Land Based Section) (Clonshagh to Baldoyle)

The proposed outfall pipeline route (land based section) runs from the proposed WwTP to the R106 Coast Road. Habitats along the proposed outfall pipeline route (land based section) included drainage ditches (FW4), improved agricultural grassland (GA1), dry meadows and grassy verges (GS2), broadleaved woodland (WD1), immature woodland (WS2), scrub (WS1), hedgerows (WL1), tree lines (WL2), arable crops (BC1), horticultural land (BC2), tilled land (BC3) and buildings and artificial surfaces (BL3).

Arable, tilled and improved fields dominate the proposed outfall pipeline route (land based section). At Kinsealy, the proposed outfall pipeline route (land based section) overlies what appeared to be willow (Salix spp.) that had been invaded by bramble scrub. This area was mapped as scrub (WS1).

Drainage ditches (FW4) or drainage ditches with hedgerows (WL1) were common to all field boundaries. Treelines (WL2) were occasional. Common species which were present here included hawthorn, blackthorn and ash.

At Mayne, the proposed outfall pipeline route (land based section) will be located within an EBZ of Baldoyle Estuary: a European Site described in Chapter 9 Biodiversity (Marine) and Chapter 10 Biodiversity (Marine Ornithology).

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Proposed Outfall Pipeline Route (Marine Section) It is proposed to tunnel the proposed outfall pipeline route (marine section) from the R106 Coast Road, beneath the European Sites at Baldoyle Bay, Portmarnock Golf Club and Velvet Strand, to emerge on the seabed approximately 600m offshore, where it will then be dredged to its termination point approximately 1km orth-east of Ireland’s Eye.

Appendix A11.2 details findings of a more detailed botanical survey conducted in May 2016 to characterise the habitats within the footprint of proposed temporary construction compound no.10 at Portmarnock, as it is located across the Golf Links Road from Baldoyle Bay SAC and adjacent to sand dune habitats of the links course which may correspond to Annex I dune habitats. None of the species that were recorded in the three quadrats within the proposed temporary construction compound site, nor indeed around the perimeter of the study area, are considered rare, and the habitats present do not correspond to any Annex I habitat for which Baldoyle Bay SAC is designated. Rare plants, which have been previously recorded at Portmarnock, did not occur in the area surveyed. The site of proposed temporary construction compound no. 10 is not designated for conservation nor is the managed vegetation analogous with any of the sand dune habitats for which the SAC is designated.

The area around the car park and the re-vegetating overflow car park are characterised as improved amenity grassland (GA2). Floristically, there is little merit to this habitat, which is managed regularly through mowing. The car park, with its hard surfaces, is classified as buildings and artificial surfaces (BL3) and is separated from the site of proposed temporary construction compound no. 10 by a linear feature comprising partially buried wooden poles.

The site of proposed temporary construction compound no. 10 is level. The managed vegetation largely corresponds with dry meadows and grassy verges (GS2). There was evidence of occasional mowing: decaying thatch among the grass sward but no signs of grazing. Floristically, and unlike the typical Fossitt (2000) description of the habitat, the area was not species-rich. Although ascribed to the meadow habitat, the species assemblage in no way reflects the typical diversity that might be expected from such a diminishing habitat. Instead, a small number of consistently occurring grasses dominated the habitat with herbaceous species scattered throughout. There were subtle variations within the sward, which related to drier areas where pedestrian activity had left distinct trails characterised by low-growing sward. Elsewhere, the wetland influence was apparent, and the graminoid component became rather lush and was accompanied by silverweed. This is indicative of the groundwater influence which occasionally affects the area. Quadrats 1 to 3 were typical of the study site, and their species assemblage accounted for the majority of the variation noted. Other species that were present, and which have been described in Appendix A11.2 in Volume 3 Part B of this EIAR, were less common or else locally abundant, often along raised banks alongside the hedges, which were left unmown. Species such as nettles (Urtica dioica) and hogweed (Heracleum sphondylium) were the key components in these areas, but others included perennial ryegrass (Lolium perenne) and patchily distributed brambles (Rubus fruticosus agg.).

The transition to sand dune vegetation, although gradual, was apparent towards the eastern tip of the site, where the pedestrian trails lead onto the boardwalk and focus the walkers through a narrow access section between the two golf courses. The vegetation was dominated by marram (Ammophila arenaria) and contained locally common patches of gorse (Ulex europeaus) dominated scrub. Other species typical of the habitat were recorded, including kidney vetch (Anthylliss vulneraria), bird foot trefoil (Lotus corniculatus) and red fescue (Festuca rubra), but were not as abundant as marram and gorse. Locally abundant patches of burnet rose (Rosa pimpinellifolia) were indicative of an aging system, where the habitat was starved of a suitable supply of fresh sand, resulting in the gradual lowering of the pH and facilitating the spread of the burnet rose. Although

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gorse was the predominant shrub here, some sea buckthorn (Hippophae rhamnoides) was noted inside the fence of one golf club.

Portmarnock Golf Course and Portmarnock Hotel and Golf Links are well established and support a number of managed habitats. Originally, they would have supported fixed dune (CD3) habitats but have long since been altered. As such, they are excluded from the SAC. They are separated from the survey area on either side by a boundary fence along which hawthorn (Cratageus monogyna) was the main vegetative component. These planted linear features were classified as hedgerows (WL1). Despite being near sand, and its presence in the soil matrix in places, the lands proposed for the proposed temporary construction compound no. 10 site shared no similarities with fixed dune vegetation. The composition of the vegetation within the immediate study area had long since lost any resemblance to fixed dune habitat owing to the management of the area. Annex I sand dune habitat does not occur within the Proposed Project.

A description of intertidal habitats is detailed in Chapter 9 Biodiversity (Marine). Protected Plant Species

No protected habitats annexed to the Habitats Directive or species of flora protected by Section 21 of the Wildlife Act 1976 (as amended) or scheduled to the Flora (Protection) Order 2015 (S.I. No. 356 of 2015) were recorded during surveys within the Proposed Project footprint. At Mayne, two sites are listed under the Flora (Protection) Order (S.I. No. 356 of 2015) and also Fingal Rare Flora sites occur (refer to FDP (FCC 2017) Map Sheet No. 15 ‘Green Infrastructure 2’ for locations of those sites). The Proposed Project will not be located in either of those sites. See also the above Section describing the absence of protected plant species at the site of proposed temporary construction compound no. 10 at Portmarnock Golf Club.

Non-Native Invasive Species Non-native (or alien) invasive species are scheduled to the European Communities (Birds and Natural Habitats) Regulations 2011 (S.I. No. 477 of 2011) (as amended) and Regulation (EU) 1143/2014 on invasive alien species (Invasive Alien Species Regulation). Giant rhubarb (Gunnera tinctoria M.) was recorded along the Tolka River downstream of the proposed orbital sewer route and the proposed Abbotstown pumping station site during the aquatic surveys. The location of giant rhubarb is at a sufficient distance from the proposed construction corridor that it will not be impacted or disturbed by construction of the Proposed Project (refer to Section 11.9). No scheduled Invasive Alien Species Regulation were observed within the Proposed Project boundary during terrestrial flora and fauna surveys.

11.3.3 Bats Bat species are not listed as Qualifying Interests of any European Site or Nationally Designated Site within 15km of the Proposed Project.

Desktop Data

The review of existing records of bat species in the Ordnance Survey 10km x 10km grid squares the Proposed Project is situated within, or adjacent to, indicated that eight of the 10 known Irish species of bat have been recorded in grid squares O03, O04, O13, O14, O23 and O24. These included common, soprano and Nathusius’ pipistrelles, Leisler’s Bat, brown long-eared bat, Daubenton’s bat, whiskered bat and Natterer’s bat as shown in Table 11.9. Known or potential bat roosts of some of these species were identified within 5km of the Proposed Project, but not within the Proposed Project boundary, and these are also shown in Table 11.9. Data on roosts were obtained from the National Bat Database (NBDC 2017), and results of previous on-site studies were obtained (Keeley 2013a; 2013b).

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Table 11.9: Bat Records in Grid Squares O03, O04, O13, O14, O23 and O24

Common Name Scientific Name O03 O04 013 O14 O23 O24 Known Known or Potential Sources Roosts Within Roosts Within the the Grid Proposed Project Squares Boundary NBDC Common pipistrelle Pipistrellus pipistrellus √ √ √ √ √ √ √ None Previous on-site studies NBDC Soprano pipistrelle Pipistrellus pygmaeus √ √ √ √ √ √ √ None Previous on-site studies NBDC Nathusius’ pipistrelle Pipistrellus nathusii √ √ None Previous on-site studies NBDC Leisler’s bat Nyctalus leisleri √ √ √ √ √ √ √ None Previous on-site studies NBDC Brown long-eared bat Plecotus auritus √ √ √ √ √ √ √ None Previous on-site studies NBDC Daubenton’s bat Myotis daubentonii √ √ √ √ √ None Previous on-site studies NBDC Whiskered bat Myotis mystacinus √ √ √ √ None Previous on-site studies NBDC Natterer’s bat Myotis nattereri √ √ √ √ None Previous on-site studies NBDC Lesser horseshoe bat Rhinolophus hipposideros None Previous on-site studies NBDC Brandt’s bat Myotis brandtii None Previous on-site studies

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Summary of Previous Survey and Desktop Data for the Proposed Project Area and its Wider Environs The bat survey and assessment conducted in 2013 (Keeley 2013a; Keeley 2013b) and 2015 found that the most widespread and abundant bat species recorded was the common pipistrelle. This species was present in suburban areas, the border between a city or suburb and its surrounding environment (urban edge) and in agricultural rural lands. Soprano pipistrelle was also widespread throughout Fingal, but less so than common pipistrelle. Leisler’s bat was recorded in several locations within the Proposed Project study area. Keeley (2013a) also noted that, while no brown long-eared bats were recorded in the course of the surveys, the echolocation of this species is weak and consequently difficult to identify from detector survey. Brown long- eared bats are known from several locations in Fingal; therefore, it is probable that this is a widespread species throughout the region.

Nathusius’ pipistrelle has been recorded in few locations in the Dublin area, including the Grand Canal (2009), Phoenix Park (2008-2013) and Islandbridge (2013). Nathusius pipistrelle is associated with broadleaved woodland, wetlands and waterbodies (Roche et al. 2014), and these habitats are not common within the Proposed Project study area.

Daubenton’s bat has been recorded throughout the Proposed Project study area, with the exception of the Grid Squares located next to the coast. A Daubenton’s roost has been recorded near Castleknock, south of Blanchardstown. Daubenton’s bat typically forages over water, and is also associated with broadleaf woodland. There are several records of Daubenton’s bat from the Tolka River at Blanchardstown.

Whiskered bat is uncommon in Fingal. There is one record from the industrial estates north of Blanchardstown, and the species is known from Phoenix Park, with a roost having been recorded to the east of Phoenix Park (1997). Records suggest that this species is associated with woodland cover, small areas of pasture, urban and scrub land cover (Roche et al. 2014). Natterer’s bat is widespread in Ireland but is much less common in the Dublin area. There are a very small number of Natterer’s bat records from Fingal. This species is associated with broadleaf woodland, riparian habitats and areas with a larger scale provision of mixed forest (Roche et al. 2014). Records for lesser horseshoe bats are mainly from Counties Cork, Kerry, Limerick, Clare, Galway and Mayo, with some records outside this core ranging from Counties Sligo and Roscommon. There are no records of lesser horseshoe bat from the Fingal area. There is one confirmed record of Brandt’s bat in Ireland, recorded in County Wicklow. There are no records of Brandt’s bat from the Fingal area.

Field Survey i. Preliminary Survey Features of potential use by foraging and commuting bats identified in the study area during the preliminary surveys undertaken between June 2012 and October 2013 included areas of broadleaved mixed woodland (Blanchardstown and Abbotstown), immature woodland (Balgriffin), lowland depositing rivers (the Tolka River at Blanchardstown) and hedgerows and treelines (throughout the Proposed Project study area). There were a number of standing trees in hedgerows within the proposed orbital sewer route. None of these trees were identified as being of high potential for supporting roosting bats or confirmed as roost sites. However, a number were of low-moderate potential for roosting bats. There were a number of mature broadleaved trees of moderate potential for roosting bats within the mixed broadleaf woodland at Blanchardstown and Abbotstown.

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The principal areas of ecological interest in relation to bats present within the Proposed Project study area include:

Hedgerows and treelines: The improved grassland and arable land covering the majority of the Proposed Project study area was of low conservation interest, and was of low interest to bats. However, many of the hedgerows which bound field systems offered connectivity in the landscape and shelter for commuting and foraging bats. Some of the older trees within hedgerows offered some potential roosting opportunities for individual/small numbers of bats. Therefore, the hedgerows and treelines in the Proposed Project study area are considered as being of local importance (higher value).

Woodlands and watercourses: The woodland along the Tolka River and the connected broadleaf woodland at Blanchardstown and Abbotstown provided an important foraging area and commuting corridor for bats, particularly as the woodland is associated with a watercourse, and there are potential roosting opportunities in mature trees. Therefore, this habitat is considered as being of local importance (higher value). ii. Activity Survey The manual and passive detector surveys undertaken within the active season in spring, summer and autumn of 2017 recorded the presence of at least six bat species within the Proposed Project study area. The results of the survey are presented in Table 11.10 along with the location and activity type. The calls on the passive detector are recorded as bat passes. For figures of survey results and raw survey data, please refer to Appendix A11.1. Proposed Wastewater Treatment Plant

The most frequently recorded species within the proposed WwTP area during the bat activity surveys undertaken between 2012 and 2017 was common pipistrelle, followed by soprano pipistrelle. These species were recorded foraging or commuting along the hedgerows bounding the fields, with most activity concentrated along the treeline adjacent to Cuckoo Stream and a hedgerow with mature standard trees located towards the south-east of the site. Leisler’s bat was occasionally recorded commuting overhead. Roosts

No evidence of bat roosts in trees within or adjacent to the footprint of the site was found during the course of the bat surveys of the Proposed Project study area conducted in 2017, or in previous surveys conducted in 2012, 2013 and 2015. A number of mature trees were identified within the proposed WwTP site that are of low-moderate potential for use by bats as roosting or resting places. These trees may be used by individuals or small numbers of bat species, but it is considered to be unlikely that large numbers of bats roost in trees in the proposed site.

Proposed Abbotstown Pumping Station

The predominant habitat within the proposed Abbotstown pumping station area is arable land. No bats were recorded within the arable field during the activity surveys undertaken between 2012 and 2017. However, common and soprano pipistrelle and brown long-eared bat were recorded foraging along the immature woodland bordering the south of the proposed Abbotstown pumping station site. A low level of common and soprano pipistrelle and Myotis species activity was recorded in the mature woodland to the north-east, outside of the proposed Abbotstown pumping station site.

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Roosts

No evidence of bat roosts in trees within or adjacent to the footprint of the proposed Abbotstown pumping station site was found during the course of the bat surveys of the Proposed Project study area conducted in 2017, or in previous surveys conducted in 2012, 2013 and 2015. Proposed Orbital Sewer Route – Blanchardstown to Clonshagh Common pipistrelle was recorded in the 2017 activity surveys foraging or commuting along the hedgerows and treelines throughout the proposed orbital sewer route. As in 2013 and 2015, there were no locations that were entirely devoid of bat activity, but some locations, such as near Dublin Airport, recorded much lower bat activity. This species was most commonly recorded foraging or commuting along hedgerows adjacent to agricultural and amenity land and at the edge of broadleaf woodland.

Soprano pipistrelle was also recorded in the 2017 activity surveys foraging or commuting along the hedgerows and treelines throughout the study area. This species was recorded alongside roads, local lanes and agricultural land.

Leisler’s bat was recorded in 2017 commuting overhead at Blanchardstown, Balseskin and Silloge. Leisler’s bat was also recorded foraging along the treelines/hedgerows at Coldwinters. The passive detector recorded Leisler’s bat passes at Williamsville and Silloge.

Whiskered/Brandt’s bat was recorded during the manual activity surveys foraging over the pond at Waterville Park at Blanchardstown (outside and to the north of the proposed orbital sewer route). Daubenton’s bat was recorded foraging in the broadleaf woodland to the north-west of Connolly Hospital at Blanchardstown, near to the Tolka River. The passive detector also recorded a relatively high level of Myotis species (unidentifiable to species level) activity in the broadleaved woodland at Blanchardstown during the manual activity surveys. Myotis species were mainly recorded in the Blanchardstown area, indicating the importance of the woodland and aquatic habitats in this area for this genus of bats. A single brown long-eared bat call was recorded during the manual activity surveys in the broadleaved woodland at Blanchardstown. Brown long-eared bat was not recorded on the passive detector, however. As mentioned previously, this species has a weak call that is difficult to pick up on detector surveys, and it is possible that this species is widespread in the Proposed Project study area.

Roosts

One soprano pipistrelle was recorded before sunset on 19 June 2017 in the woodland at Blanchardstown, and one large mature Sycamore tree in the woodland directly adjacent to the boundary of the proposed orbital sewer route at Blanchardstown was identified as a probable bat roost for an individual soprano pipistrelle. Small numbers of both soprano pipistrelle and common pipistrelle were recorded at dawn swarming around two mature oak trees located approximately 21m to 25m to the north-west of the proposed orbital sewer route in the woodland at Blanchardstown. (For the location of these trees, refer to Figure 3.5 of the Bat Survey Report in Appendix A11.1.) No further evidence of bats roosts in trees was found during the course of the bat survey of the Proposed Project study area conducted in 2017, or in previous surveys conducted in 2012, 2013 and 2015. However, a number of mature trees were identified within the Proposed Project study area that are of low-moderate potential for use by bats as roosting or resting places. These trees may be used by individuals or small numbers of bat species, but it is considered to be unlikely that large numbers of bats roost in trees in the Proposed Project study area.

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During the course of the bat surveys undertaken in 2015, soprano pipistrelle and common pipistrelle were recorded early in the evening at Silloge, indicating the potential presence of a roost in the vicinity. This area was re-surveyed in 2017, and no-evidence of a roost was observed within the Proposed Project study area or its immediate environs at this location. Leisler’s bat was recorded near the proposed orbital sewer route at Coldwinters early in the evening during surveys in 2013 and again in 2017. The nearest roosting site at Coldwinters was not shown to be a roost site in 2013 or 2017. As noted previously, the trees within the Proposed Project study area may have been used by individuals or small numbers of bat species but were not suitable to support larger numbers of bats (i.e. a maternity roost).

Proposed Outfall Pipeline Route (Land Based Section) (Clonshagh to Baldoyle) Common and soprano pipistrelle were recorded foraging or commuting along the mature hedgerows present in the Kinsealy area.

Leisler’s bat was recorded commuting overhead throughout the proposed outfall pipeline route (land based section). This species was also recorded foraging along the R123 Moyne Road to the south of the proposed outfall pipeline route (land based section).

A single brown long-eared bat call was recorded adjacent to a hedgerow at Kinsealy. Roosts

Soprano pipistrelle was recorded on 22 June 2015 emerging from a farm building at Bohammer, near Kinsealy, adjacent to the proposed outfall pipeline route (land based section) (see Figure 3.5 of Appendix A11.1). During the course of the bat surveys undertaken in 2015, soprano pipistrelle was recorded early in the evening at Drumnigh. This area was re-surveyed in 2017, and no evidence of a roost was observed within the Proposed Project study area or its immediate environs at this location. It is noted that no structures within the Proposed Project study area will require demolition as part of the Proposed Project.

Information on bat roosting preferences adapted from Irish Bats in the 21st Century (Roche et al. 2014) and Bat Surveys for Professional Ecologists (Collins 2016) is included in the bat report (Appendix A11.1), where the roosting preferences of bat species that have either been confirmed as present, or are likely to be present, in the study area are described.

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Table 11.10: Bat Activity Recorded Within the Proposed Project Study Area in 2017

Species Location Project Element Activity Habitat Proposed orbital Blanchardstown Foraging Broadleaf woodland edge and pond sewer route Proposed Abbotstown Abbotstown pumping Foraging Broadleaf woodland edge station Proposed orbital Coldwinters Foraging Pasture and treeline sewer route Common pipistrelle Proposed orbital Balseskin Foraging Pasture and treeline sewer route Proposed orbital Silloge Foraging Hedgerow/treeline sewer route Clonshagh Proposed WwTP Foraging Hedgerows/treelines Proposed outfall Kinsealy pipeline route (land Foraging/commuting Hedgerow/treeline/amenity based section) Proposed orbital Blanchardstown Foraging/commuting Broadleaf woodland and park sewer route Proposed Broadleaf woodland edge and improved Abbotstown Abbotstown pumping Foraging grassland station Proposed orbital Balseskin Foraging Pasture and treeline sewer route Proposed orbital Williamsville Pass Hedgerow/treeline sewer route Soprano pipistrelle Proposed orbital Coldwinters Foraging Hedgerows/treelines lining local road sewer route Clonshagh Proposed WwTP Foraging Hedgerows/treelines Proposed outfall Kinsealy pipeline route (land Foraging Conifer plantation edge based section) Proposed outfall Portmarnock pipeline route Foraging Hedgerow/treeline (marine section) Proposed orbital Blanchardstown Foraging Broadleaf woodland sewer route Proposed Broadleaf woodland edge and improved Abbotstown Abbotstown pumping Foraging/commuting grassland station Proposed orbital Pasture and hedgerows/treelines lining local Coldwinters Foraging sewer route road Proposed orbital Balseskin Foraging/commuting Pasture and treeline sewer route Proposed orbital Williamsville Pass Hedgerow/treeline sewer route Leisler’s bat Proposed orbital Dubber’s Cross Pass Hedgerow/treeline sewer route Proposed orbital Silloge Pass and foraging Hedgerow/treeline sewer route Clonshagh Proposed WwTP Foraging/commuting Hedgerows/treelines Proposed outfall Kinsealy pipeline route (land Foraging/commuting Hedgerow/treeline/amenity based section) Proposed outfall Portmarnock pipeline route Foraging Hedgerows/treelines (marine section)

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Species Location Project Element Activity Habitat Proposed orbital Blanchardstown Foraging Broadleaf woodland sewer route Proposed Brown long-eared Abbotstown Abbotstown pumping Foraging Broadleaf woodland edge bat station Proposed outfall Kinsealy pipeline route (land Foraging/commuting Hedgerow/treeline/amenity based section) Whiskered/Brandt’s Proposed orbital Blanchardstown Foraging Pond and parkland bat sewer route Proposed orbital Daubenton’s bat Blanchardstown Foraging Broadleaf woodland sewer route Proposed orbital Blanchardstown Pass Broadleaf woodland sewer route Proposed Myotis spp. Abbotstown Abbotstown pumping Pass Broadleaf woodland ride station Proposed orbital Coldwinters Pass Hedgerow sewer route

The results of the activity survey are illustrated in Figure 3.3 and Figure 3.4 of the Bat Survey Report in Appendix A11.1.

11.3.4 Mammals (Other than Bats) Badger

Badger was recorded during the surveys. Due to the high level of persecution of badger and legal protection afforded to this species (badger is listed in the Fifth Schedule of the Wildlife Act 1976 (as amended) and protected under Section 23), information pertaining to the location of setts is treated as confidential. For this reason, figures illustrating and identifying the location of badger setts are not provided with this Chapter. This information is contained within a separate confidential report which has been provided to ABP and the Development Applications Unit of the Department of Culture, Heritage and the Gaeltacht. Eight badger setts were identified within the Proposed Project study area, and they are summarised in Table 11.11.

Table 11.11: Badger Setts Occurring Within the Proposed Project Study Area

Sett Location Distance to Proposed Project Description

Within proposed construction corridor. Old and disused five-entrance sett, with old spoil heaps. S1 Tolka River Valley No sign of recent activity. Completely overgrown with ivy 6m north of the proposed 20m and bramble. wayleave. 110m east-north-east of S1. 7m north of the proposed Two entrances recently used set within a large area of construction corridor. undisturbed dense scrub and felled trees. No bedding or S2 Connolly Hospital 17m north of the proposed 20m active spoil heaps were visible, but surveyor views were wayleave. extremely obscured. Over six well-trodden mammal paths 30m west of proposed Abbotstown leading in and out of area. pumping station. 340m north-east of S2. 3m north-west of the proposed Disused outlier, two-entrance sett, with small spoil heaps S3 NSC construction corridor. within mature deciduous woodland. Sett occupied by rabbit 23m north-west of the proposed 20m at time of survey. Adult badger skull found nearby. wayleave.

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740m north-east of S3. Disused outlier, single-entrance sett within earth S4 NSC 90m north-west of the proposed embankment and dense unmanaged hedgerow of dense construction corridor. bramble and ivy. No visible paths or tracks. 100m north-east of S4. Disused outlier, single-entrance sett within earth S5 NSC 70m north-west of the proposed embankment with field drain and dense unmanaged construction corridor. hedgerow of dense bramble and ivy. Occupied by rabbit.

62m north-east of S5. Disused outlier, single-entrance sett within earth embankment with dense unmanaged hedgerow of dense S6 NSC 38m west-north-west of the bramble and ivy. Small spoil heap present, and some proposed construction corridor. mammal paths in ivy. Occupied by rabbit. 150m north-east of S6. 6m east of the proposed Disused outlier, single-entrance sett within earth S7 NSC construction corridor. embankment with wet ditch at base, Small spoil heap 5m east of the proposed 20m present overgrown by dense ivy. Occupied by rabbit. wayleave. Abandoned outlier, two-entrance sett with small spoil On boundary of the proposed heaps, currently being used by rabbit. Signs of human interference are evident with entrances blocked by large Private land at construction corridor. S8 boulders and fence post. 33kV Electricity Supply Board Kinsealy 8m north of the proposed 20m overhead line directly adjacent. Another disused and wayleave. overgrown single-entrance sett occurs 25m east along the hedgerow.

The badger setts identified in these surveys are of local importance (higher value), as they provide shelter for a local population of a protected species.

Badger prints were recorded within the footprint of the proposed WwTP. There were some mammal paths along the hedgerows at the proposed WwTP site, but there were no badger guard hairs or latrines observed at the proposed WwTP site, and no signs of excavations or underground structures providing shelter for protected species.

Other Mammal Structures Four fox dens were noted within the Proposed Project boundary. Two were discovered in woodland of the Tolka River Valley Park between the Proposed Project boundary and the N3 National Road. One was recorded in woodland 25m from the Proposed Project boundary beside the R135 Finglas Road. One was recorded on the northern boundary of the Proposed Project boundary at Merryfalls.

Evidence of Other Mammals

There are records of otter along the Tolka River, Santry River and Mayne River as well as along Baldoyle Bay (Biodiversity Ireland 2017). As such, otters may reasonably be expected to occur in the area. No signs of otter were observed in terrestrial ground mammal field surveys. Section 11.9 of this Chapter describes the potential for otter at each of the main watercourses within the Proposed Project study area.

In the wider Proposed Project boundary, badger latrines, fox faeces, mammal prints and significant mammal tracks were noted infrequently during surveys, and their locations are presented in a confidential appendix to ABP. Many prints found within the Proposed Project study area were that of domestic cats and dogs. Rabbit (Oryctolagus cuniculus) was observed on many occasions and numerous small holes and burrows attributable to rabbits were observed throughout the Proposed Project study area.

Grey squirrel was observed at four locations along the proposed pipeline routes. The locations of these sightings are illustrated in Figure 11.11 Mammal Survey Results (1 of 6) to Figure 11.16 Mammal Survey Results (6 of 6) contained in the separate confidential report.

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11.3.5 Farmland Birds The purpose of this Section is to highlight the existing nature of bird interests, specifically to report on those bird species that were present within the Proposed Project boundary and adjacent buffer, that are categorised as being of conservation importance and on which there is the potential for significant impacts to arise from the Proposed Project. The bird species present within the 250m buffer of the Proposed Project boundary were all typical common birds associated with highly modified agricultural landscapes, with open fields, hedgerows, treelines, pockets of woodland, drainage ditches and watercourses. The species recorded are therefore entirely in keeping with what would be anticipated, given the land uses and habitats revealed by the extended Phase 1 Habitat Survey.

The breeding bird data demonstrate that the only Birds Directive Annex I species present within the study area was kingfisher, which was present at a single location on the Tolka River west of Abbotstown. No other Annex I species were present within the Proposed Project study area (or at a distance from the Proposed Project boundary). The only other species of note, in conservation terms, are those listed as Red or Amber Birds of Conservation Concern in Ireland (BOCCIs) (Colhoun and Cummins 2013). Seven Red-listed species were recorded within the survey area, of which grey wagtail, yellowhammer, lapwing and meadow pipit were confirmed, probable or possible breeders, albeit in very low numbers and black-headed gull, curlew and herring gull were recorded over-flying, loafing or foraging. Twenty-two Amber-listed species were recorded, but there was no indication that the Proposed Project study area was of special importance for any of these species, reflecting the highly modified and largely semi-urban or intensively farmed nature of the majority of habitats.

Given the habitats recorded throughout the terrestrial footprint of the Proposed Project, the breeding bird assemblage present is judged to be an ecological feature of site level importance. There were no agglomerations of winter birds, such as geese or other wildfowl, or species reliant on farmland. The Proposed Project study area is therefore of no more than local importance for wintering birds.

The proposed WwTP site will have the largest permanent footprint of all elements of the Proposed Project, and it is considered helpful to provide a more detailed breakdown of the Red- and Amber-listed breeding birds recorded for this part of the Proposed Project. All bird species encountered within the footprint of the proposed WwTP were recorded, including those in flight, resulting in a total of 25 species being recorded over the combined breeding season surveys of 2012, 2013, 2015 and 2017. Of these, three were Red-listed BOCCIs and nine were Amber-listed BOCCIs. A full list of the bird species recorded is provided in Table 11.12.

The arable fields and defunct hedgerows, which dominated the proposed WwTP site, provide some limited nesting to species typical of the intensified agricultural environment. The presence of two to three pairs of yellowhammer was a noteworthy interest, given this is a Red-listed BOCCI, and breeding is considered probable. The overall breeding bird assemblage within the footprint of the proposed WwTP site was therefore considered to be an ecological feature of local importance (higher value).

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Table 11.12: Breeding Bird Survey Results and Sensitivity of Species at the Proposed WwTP Site

Approx. No. of Territories Breeding Conservation Ecological Species 2012 2013 2015 2017 Evidence Status Sensitivity Black-headed gull 0 0 0 0 N – F Red (Breeding) Medium Greenfinch 1 1 0 0 Pr – P Amber Low Grey wagtail 0 0 0 0 N – U Red (Breeding) Medium House martin 0 0 0 0 N – F Amber Low House sparrow 0 0 0 0 Po – H Amber Low Linnet 0 0-1 0 0 Po – H Amber Low Sparrowhawk 0 0 0 0 N – F Amber Low Starling 0 0 0 0 N – F Amber Low Swallow 0 0 0 0 N – F Amber Low Swift 0 0 0 0 N – F Amber Low Teal 0 0 0 1 N – U Amber Low Yellowhammer 3 2 2 2 Pr – N Red (Breeding) Medium Key to Table Red- and Amber-listed BOCCIs (Colhoun and Cummins 2013) The breeding status of all species encountered during survey were classified into four categories: Confirmed (Br), Probable (Pr), Possible (Po) and Non-breeder (N), based on BTO categories of breeding evidence. Only the strongest level of breeding evidence recorded for each species is presented. Where a species was encountered within suitable nesting habitat but was known with a high degree of confidence not to have bred within the survey area, the species was categorised as a non-breeder. N = Non-breeding – F (flying over), U (summering non-breeder) Po = Possible breeding – H (observed in suitable nesting habitat) Pr = Probable breeding – P (pair in suitable nesting habitat), N (visiting probable nest site) Sensitivity rated according to Percival (2003)

11.3.6 Other Species Groups Smooth Newt

Smooth newts are listed in the Fifth Schedule of the Wildlife Act 1976 (as amended) and protected under Section 23 of the Act. They were recorded at five ponds within Site 1 Coldwinters in 2017 and at eight ponds in 2015. No smooth newts were recorded at Sites 2 and 3. The Smooth Newt Survey Report (Appendix A11.3) provides full details of the survey results.

Site 1, Pond 1 was observed to contain adult male and females and also juvenile newts in all three surveys undertaken in 2017. This site was approximately 56m from the Proposed Project boundary. Pond 7 contained a single male and female newt on the third visit only. Pond 7 was approximately 50m from the Proposed Project boundary. Pond 11 contained small numbers of newts during the first two visits and was within the Proposed Project boundary. Pond 15 was dry during the first visit and two female newts were found during the third visit. Pond 15 is located on the Proposed Project boundary. A single juvenile newt was found in Pond 16 on the second visit only. Pond 16 approximately 130m from the Proposed Project boundary. Pond 11 and Pond 15 are approximately within or on the boundary of the Proposed Project boundary and also contained smooth newt during surveys carried out in May and June 2017.

The above results and pond locations are illustrated in Figures 1-4 of Appendix A11.3. Site 2 had multiple waterbodies with submerged and emerging vegetation, but both fish (stickleback) and birds were present. Predators reduce the likelihood of a waterbody being of any significance for newts. A golf course lies immediately north and west, and a flowing stream occurs immediately south as well as major road network to the south and east.

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Site 3 had suitable habitat, damp un-grazed grassland with scrub, but was deemed to be sub-optimal for newts due to the presence of a large car park immediately south and a major road immediately east. Waterbody no. 4 showed signs of oil on the water's surface. Such pollutants may deter smooth newt or their prey. Damp un-grazed fields were present to the north and west. The ponds identified in these surveys are of local importance (higher value) as they provide shelter for a local population of a protected species.

11.3.7 Summary Valuation of Terrestrial Biodiversity Features Table 11.13 outlines the terrestrial biodiversity features recorded along the Proposed Project and their value at a geographic scale.

Table 11.13: Terrestrial Biodiversity Features

Feature Value Baldoyle Bay SAC, SPA International importance Dublin Bay UNESCO Biosphere Reserve International importance Baldoyle Bay proposed NHA National importance Abbotstown NDA County importance Silloge Park Golf Club NDA County importance Baldoyle Bay EBZ County importance Habitats Of varying local importance, from lower to higher value Terrestrial non-native invasive species Do not occur Mammals (other than bats) Local importance (higher value) Bats Local importance (higher value) Farmland birds (proposed pipeline corridor) Local importance (lower value) Farmland birds (proposed WwTP) Local importance (higher value) Smooth newts Local importance (higher value)

11.4 Impact of the Proposed Project on Terrestrial Biodiversity – Construction Phase ‘Significant’ impacts are moderate or major impacts which require avoidance, reduction or counterbalancing measures to mitigate or offset their adverse impacts. Beneficial impacts do not require mitigation measures as their effects are welcomed. Impacts have been assessed in accordance with the geographic frame of reference and criteria for valuing ecological features described in Table 11.6 and criteria for predicting magnitudes of effect described in Table 11.7. The total construction period for the overall Propose Project will be approximately 48 months, including 12 months of commissioning. Potential impacts of the Proposed Project on terrestrial biodiversity have been predicted in the absence of mitigation. The Proposed Project has been designed, as far as possible, to avoid high value biodiversity receptors, and much of the Proposed Project (i.e. the proposed orbital sewer route and the proposed outfall pipeline route) will be placed underground with surface habitats reinstated. The proposed Abbotstown pumping station, WwTP, permanent access/egress roads, access chambers, manholes, air valves and scour valves will have an above ground footprint through the Operational Phase. Therefore, loss of habitats of local importance (both lower and higher value) is inevitable for elements of the Proposed Project with an above ground footprint into

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the Operational Phase. Locations are shown on Planning Drawing Nos. 32102902-2101 to 32102902-2109 and details as shown on Planning Drawing Nos. 32102902-2200 to 32102902-2204.

The construction methodology for the proposed pipeline routes will involve both open cut and trenchless methods. The construction methodology that will be employed for the majority of the proposed orbital sewer route will be conventional open cut, whereby the land is stripped of topsoil, a trench of suitable dimension is excavated and the pipe is installed, on suitable bedding material, to the lines and levels determined by the design, depending on whether the pipeline is a gravity sewer or a rising main. Following testing of the pipeline, it is then surrounded with specified material and the trench is backfilled.

For the proposed WwTP, the land will be stripped of topsoil. Construction of the proposed WwTP will involve excavation for building foundations and tanks; reinforced concrete works; erection of structural steel/concrete building frames; erection/building walls (concrete/blockwork); erection of prefabricated cladding panels to walls and roofs of buildings; erection of prefabricated steel tanks; mechanical and electrical fit out of buildings and tanks; installation of below and above ground pipework; construction of screening berms; construction of access/egress roads to site and internal circulation roads, car parks and footpaths; landscaping and final planting.

At those boundaries adjoining the rural context to the east, north and west, a series of embankments planted with dense bands (approx. 15-20m wide) of hedgerow tree species will provide visual screening of the proposed WwTP. The embankments will rise to a maximum height of about 4m with gentle outward facing slopes in order to blend with the flat to mildly undulating terrain context that surrounds the site. This will be achieved using a buffer zone width of approximately 60m. Between the mounds, specimen trees will rise from a more open wildflower meadows context. The dense but linear bands of hedgerows vegetation topping the mounds will reference the hedgerows and tree-lined field boundaries of the agricultural fields nearby. The meadow and specimen trees between the dense sections of hedgerow planting reference the parkland aesthetic of the nearby demesne landscapes to the east.

For the proposed Abbotstown pumping station site, the land will be stripped of topsoil followed by wet/dry well construction, i.e. the pumps will be mounted in a dry well with the suction pipework being constructed in the pumping station wet well. The superstructure will be located directly above the wet/dry well, with the cover slab acting as a foundation for the superstructure. This will also facilitate access to the pumps. The superstructure will be a maximum of 10m above ground level. Due to the invert level of the incoming sewer from the Blanchardstown Regional Drainage Scheme, the wet well will be 17m below ground level. This will involve deep excavation, with most of this taking place in rock. For all elements of the Proposed Project, including the proposed temporary construction compounds, site clearance works will generally require the removal of hedgerows and surface habitats within the working width of the Proposed Project boundary. Therefore, there will be direct, although not necessarily permanent, impacts on all habitats along the Proposed Project boundary.

Where protected species have been found to occur along the Proposed Project boundary, construction of the Proposed Project may result in disturbance to or displacement of protected species to adjacent habitats. Removal of habitats may impede the ability of species to move throughout the landscape within their territories.

Potentially significant Construction Phase impacts are summarised in Table 11.14 and described thereafter.

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Table 11.14: Potentially Significant Construction Stage Impacts of the Proposed Project on Terrestrial Biodiversity

Feature Value Potential Impacts During Construction Phase

Habitat Loss, Deterioration and Disturbance to or Displacement of Protected Fragmentation Species or Reduction in Habitat Availability European Sites, International No impact. No impact. their buffer importance There will be no direct or indirect loss, There will be no direct or indirect disturbance to zones and the deterioration or fragmentation of terrestrial or displacement of terrestrial protected species, UNESCO habitats for which these sites have been or reduction in terrestrial habitat availability to Biosphere designated. protected species for which these sites have Reserve been designated. Inland NHAs National No impact. No impact. importance There will be no direct or indirect loss, There will be no direct or indirect disturbance to deterioration or fragmentation of terrestrial or displacement of terrestrial protected species, habitats for which terrestrial pNHAs have been or reduction in terrestrial habitat availability to designated. protected species for which any terrestrial pNHA sites have been designated. NDAs County No likely significant impact. No impact. importance The Proposed Project will pass 10m below the Not applicable as NDAs are not designated in NDA at Abbotstown and will partially tunnel the FDP (FCC 2017) for the occurrence of through the golf course at Silloge. NDAs have protected species been identified to provide opportunities for habitat improvement. A temporary construction site corridor running through the NDA does not prevent those opportunities arising. GS2 grassland Local No likely significant impact. Not applicable importance Direct impact will occur, as areas of dry (higher value) meadows and grassy verges will be removed during construction. GS4 grassland Local No likely significant impact. Not applicable importance Direct impact will occur, as areas of wet (higher value) grassland will be removed during construction. (Mixed) Local No likely significant impact. Potentially significant impact. broadleaved importance Direct impact will occur, as areas of (mixed) Indirect impact on species will occur, as these woodland, (higher value) broadleaved woodland, scrub, hedgerows and habitats are used by protected species to move scrub, treelines will be removed during construction. throughout the wider area and their removal hedgerows and may impede the ability of species to do that treelines throughout construction. Fixed dune Local No impact. Not applicable habitat at importance Construction of the project will avoid this Portmarnock (higher value) habitat. GA1 and GA2 Local No likely significant impact. Not applicable grasslands, spoil importance Direct impact will occur, as areas of grasslands, and recolonising (lower value) spoil and recolonising bare ground, arable bare ground, crops, horticultural land and tilled land will be arable crops, removed during construction. horticultural land and tilled land Bats Local Not applicable Potentially significant impact. importance No direct impacts on roosts. Indirect impact on (higher value) bats may occur as their foraging and commuting routes may be severed by loss of broadleaved woodland, scrub, hedgerows and treelines.

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Feature Value Potential Impacts During Construction Phase

Habitat Loss, Deterioration and Disturbance to or Displacement of Protected Fragmentation Species or Reduction in Habitat Availability Farmland birds Local Not applicable Potentially significant impact. importance No direct impacts on nests in use, but nesting (higher value) habitat will be removed during construction. Breeding species will be displaced to adjacent woodland, scrub, hedgerows and treeline habitat. Smooth newt Local Not applicable Potentially significant impact. importance Direct impacts on ponds used by newts may (higher value) occur during construction. Species will be displaced to adjacent ponds. Newts may be accidentally harmed in the absence of any special measures. Wildlife offence may occur. Otters Local Not applicable No impact. importance No direct or indirect impacts on any features (higher value) identified as being used by otters shall be affected during the Construction Phase. Badgers Local Not applicable Potentially significant impact. importance Direct impacts on badger setts within the (higher value) proposed construction corridor will occur during construction. Species will be displaced to adjacent habitat. Badgers may be accidentally harmed in the absence of any special measures. Wildlife offence may occur.

11.4.1 Designated Sites European Sites No component or aspect of the Proposed Project is proposed to be located within any habitat above the mean high-water mark which is part of a European Site. The Golf Links Road separates the location of proposed temporary construction compound no. 10 and the saltmarsh habitats of Baldoyle Bay. No Annex I habitat for which the Baldoyle Bay SAC has been designated occurs at proposed temporary construction compound no. 10 on the Golf Links Peninsula. Chapter 9 Biodiversity (Marine) and Chapter 10 Biodiversity (Marine Ornithology) set out an impact assessment of the Construction Phase of the Proposed Project on European Sites, as their Qualifying Interests and SCIs correspond to ecological features described under each of these respective chapters.

Other Designated Areas No component or aspect of the Proposed Project is proposed to be located within any terrestrial NHA or pNHA. The nearest pNHA is located 350m from the Proposed Project and is an enclosed canal. No indirect impacts upon the pNHA are predicted. The Sluice River Marsh is over 900m from the Proposed Project and Feltrim Hill is over 1km from the Proposed Project. No indirect impacts are predicted upon these features at such distances.

The Proposed Project will pass under an NDA at its western terminal end in woodland enveloping Connolly Hospital at Abbotstown. The NDA includes a southward extension of woodland beyond the Tolka Valley Regional Park, and will turn north-east, skirting the M50 Motorway for approximately 1km. The proposed

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orbital sewer route will be directionally drilled at a depth of approximately 10m for the first 1km (Planning Drawing No. 32102902-2100) and will pass underneath the roots of trees (Dobson 1995) comprising woodland in the Tolka Valley Regional Park part of the NDA, avoiding any direct or indirect habitat impact. The proposed orbital sewer route will be constructed by shallow trench through the remainder of the NDA as it skirts along the M50 Motorway. A temporary and direct habitat impact will occur whilst the proposed orbital sewer route is being constructed in the proposed construction corridor. The temporary direct habitat loss will not undermine the NDA in terms of its potential to achieve longer-term opportunities for habitat improvement, as in the longer-term the proposed orbital sewer route will be installed underground, and will pass through only a small part of the NDA. The overall impact is minor adverse and short-term. This is not significant.

The Proposed Project will pass through and encroach into an NDA at Silloge Park Golf Club. The proposed orbital sewer route shall be constructed through this area by combination of surface trench and directional drill. The temporary direct habitat loss will not undermine the NDA at Silloge Park Golf Club in terms of its potential to achieve longer-term opportunities for habitat improvement as the proposed orbital sewer route will be installed underground, and will pass through only a small part of the NDA. The overall impact is minor adverse and short-term. This is not significant.

The Proposed Project will be located within an EBZ at Mayne. Proposed temporary construction compound no. 9, accommodating the tunnel drive reception shaft, west of Baldoyle Bay SPA and north of Baldoyle Bay SAC will be within the ‘Portmarnock South Zoned Lands’. This is an area for which a Local Area Plan has been prepared and adopted. It includes a ‘quiet zone’ as a supporting function for migratory birds using the estuary and arable crop areas for native bird species. Proposed temporary construction compound no. 9 comprises approximately 20% of the quiet zone. Construction Phase impacts of the Proposed Project at this location, including predicted noise levels and how the bird species which use the estuary are likely to react, are discussed in Chapter 10 Biodiversity (Marine Ornithology), and in the NIS.

11.4.2 Terrestrial Habitats Proposed Wastewater Treatment Plant

With reference to Figure 11.8 Habitat Survey Results (Sheet 4 of 6), the arable fields (BC1) and horticultural lands (BC2) which the proposed WwTP overlies are of ecological value at a site level. Approximately 1.6km of hedgerows will be removed to facilitate the Proposed Project, 800m of which abut a drainage ditch (FW4) travelling east to west along the southern boundary of the proposed WwTP site, including small sections of hedgerow removed for the proposed access road. Hedgerows are a feature of local importance (higher value) and their loss will be permanent. Drainage ditches and hedgerows provide valuable habitat, giving refuge for flora and fauna absent in intensively managed crop fields and they provide an ecological corridor function. The overall impact will be the direct loss of hedgerows. In accordance with Table 11.6, a feature of local importance (higher value) is evaluated as a key feature of local importance where that feature is important for and supports other features (such as an ecological corridor function for species). The overall impact is moderate adverse and permanent. This is significant.

Proposed Abbotstown Pumping Station

With reference to Figure 11.5 Habitat Survey Results (Sheet 1 of 6), the proposed Abbotstown pumping station will result in the loss of 0.4ha of an arable field (BC1). The ecological value of the arable field is of local importance (lower value). The immature (WS2) and mixed broadleaved woodlands (WD1) between the proposed Abbotstown pumping station and the M50 Motorway are of local importance (higher value) and part of a key linear feature of local importance. The arable grassland will be lost but the woodland will not be affected by construction. The overall impact is negligible and permanent. This is not significant.

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Proposed Orbital Sewer Route (Blanchardstown to Clonshagh) Including Proposed Temporary Construction Compounds

With reference to Figure 11.5 Habitat Survey Results (Sheet 1 of 6) to Figure 11.8 Habitat Survey Results (Sheet 4 of 6), the construction method employed will be trenches of varying depths that will be backfilled with granular material and excavated topsoil once the laying of the proposed orbital sewer route is complete. For certain natural or man-made obstructions, such as rivers, roads or major infrastructure, trenchless techniques will be used. Much of the proposed construction corridor habitats are intensively farmed lands (such as GA1, BC1) or heavily modified habitats (ED2, ED3) of local importance (lower value). Some hedgerows (WL1), immature woodland (WS2) and (mixed) broadleaved woodland (WD1) were found along the proposed orbital sewer route and will be disturbed when they are subject to open trenching. These habitats are of local importance (higher value) and evaluated as a key feature of local importance where they support other features (such as an ecological corridor function for species) in an otherwise agricultural grassland dominated landscape. In the absence of mitigation, the hedgerow and woodland will be permanently lost. The overall impact is moderate adverse and permanent. This is significant.

Up to 0.6ha of neutral grassland (GS1) in Connolly Hospital grounds will be directly impacted. These are overgrown, species-poor swards and are of local importance (lower value). This habitat is not considered to be a key feature of local importance. The impact is slight adverse and short-term. This is not significant.

The wet grassland (GS4) field at Kildonan is of ecological value in a local context (higher value) given the reasonable diversity of flora occurring in it. Topsoil stripping will result in removal of the seedbank of this wet grassland community unless it is retained and reused. In the absence of mitigation, this habitat will be permanently lost. This habitat does not occur elsewhere in the locality, and it is a key feature of local importance. The overall impact is moderate adverse and permanent. This is significant. Proposed Outfall Pipeline Route (Land Based Section) (Clonshagh to Baldoyle) Including Proposed Temporary Construction Compounds

With reference to Figure 11.9 Habitat Survey Results (Sheet 5 of 6) and Figure 11.10 Habitat Survey Results (Sheet 6 of 6), the proposed outfall pipeline route (land based section) will mostly be constructed using open trench excavation. The habitats are mainly intensive agricultural lands of local importance (lower value). Hedgerows (WL1), a treeline (WL2), wet grassland (GS4) occurring at Drumnigh and willow-bramble scrub (WS1) will be directly impacted by construction. Up to 0.9ha of willow-bramble scrub (WS1) will be directly impacted resulting in habitat loss. These habitats are of local importance (higher value). Much of the remainder of the proposed outfall pipeline route (land based section) comprises intensively farmed lands (such as GA1, BC1) or heavily modified habitats (ED2, ED3) of local importance (lower value). In the absence of mitigation, the scrub and hedgerow habitat will be permanently lost. The scrub habitat occurring along this section of the proposed outfall pipeline route (land based section) which will be lost occurs widely in the locality. The wet grassland strip is narrow and small in size. It is not a key feature of local importance, and the overall impact is slight adverse and permanent. The hedgerow and scrub habitat is considered to be a key feature of local importance where it supports other features (such as an ecological corridor function for species) in an otherwise agricultural grassland dominated landscape. In the absence of mitigation, the hedgerow and scrub will be permanently lost. The overall impact is moderate adverse and permanent. This is significant. Sections of hedgerow (WL1) and their variable components (earth banks (occasional), ground flora, trees and shrubs) will be removed. The hedgerow network will be severed. The proposed construction corridor for the proposed outfall pipeline route (land based section) is 40m wide to allow for the movement of heavy plant and temporary storage of construction materials. The proposed construction corridor will be reduced to a proposed

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20m wayleave to facilitate maintenance of the pipeline for its operational life. The main Construction Phase impact will be the loss of up to 40m sections of existing hedgerows that are crossed by the proposed outfall pipeline route (land based section). However, normal practice is not to strip hedgerow sections from the full proposed construction corridor width, but instead to remove only what is required to facilitate the pipeline trench, haul route and any topsoil strip storage area beside the trench (approximately 20m). This type of hedgerow loss will occur at 35 separate sections of hedgerow, replaced by a strip of bare ground the width of the proposed construction corridor which will remain until a grass sward is reinstated. In the absence of mitigation, approximately 1.4km of hedgerows will be permanently lost, and the local network of hedgerows functioning as wildlife corridors will be severed. This habitat is of local importance (higher value) and a key feature of local importance. The overall impact is moderate adverse and permanent. This is significant.

Proposed Outfall Pipeline Route (Marine Section) - Proposed Temporary Construction Compounds for Microtunnelling With reference to Figure 11.10 Habitat Survey Results (Sheet 1 of 6), proposed temporary construction compound no. 9 west of Baldoyle Bay will be located in horticultural land (BC2). East of Baldoyle Bay, proposed temporary construction compound no. 10 will overlie an area of improved amenity grassland (GS2). These habitats are of local importance (lower value). Managed fixed dune (CD3) habitat (of local value) occurs to the east of proposed temporary construction compound no. 9, but the proposed outfall pipeline route (marine section) will be tunnelled under here, so no habitat loss is likely to occur. Habitats will be lost in the footprint of proposed temporary construction compounds no. 9 and no. 10. These habitats will be permanently lost. The value of the features is of local importance (lower value). The overall impact is negligible and permanent. This is not significant.

11.4.3 Bats Results of the most recent 2017 survey supplemented by previous surveys between 2012 and 2015 indicate that the Proposed Project study area supports at least six species of bat. Furthermore, there are existing records of eight bat species from the 10k grid squares that the Proposed Project study area is located within. Due to their use of wide areas of landscape and their low birth rate, bats are vulnerable to potential impacts from linear projects such as the installation of the proposed pipeline routes.

Proposed Wastewater Treatment Plant The removal of sections of linear features such as hedgerows and treelines may act as a barrier to species that are reluctant to cross open ground. Woodland adapted species (such as Myotis species, brown long- eared bat, lesser horseshoe bat) and small generalists (Pipistrellus species) make more use of, and are more dependent on, these features than larger open-air species (Leisler’s bat). The construction of the proposed WwTP will involve the removal of approximately 1.6km of hedgerows of local value that currently function as flight lines for common and soprano pipistrelle. The removal of hedgerows that function as foraging and commuting habitat would have a direct and moderate adverse impact on bats at the local level. This impact would be permanent and significant.

The loss or fragmentation of foraging habitats (such as hedgerows) may reduce the available insect prey species and also reduce feeding area for bats. The reduction of foraging habitat would have a direct significant adverse impact on bats at the local level. This impact would be permanent and irreversible.

Loss of mature trees within hedgerows may reduce potential roosting sites for individual bats. No bat roosts were identified within the footprint of the proposed WwTP. However, occupation of roosts in trees by bats may

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be very transient, and there is potential that the mature broadleaf trees in the footprint of the proposed WwTP may be used occasionally as roosting or resting places by individual/small numbers of bats. Therefore, there is potential for significant direct adverse impacts to individual bats as a result of the clearance of mature broadleaf trees during the Construction Phase. This would be significant at the local level. When bats emerge from roosts they tend not to echolocate but rely on eyesight to fly from the roost to adjoining treelines or hedgerows. Various studies have shown that bats’ eyesight works best in dim light conditions; where there is too much luminance bats’ vision can be reduced, resulting in disorientation. Too much luminance at bat roosts may cause bats to desert a roost. Light falling on a roost exit point can delay bats from emerging and miss peak levels of insect activity at dusk, and any delays of emergence can reduce feeding periods. Studies have also found that lighting can cause avoidance of an area for commuting bats and can prevent or reduce foraging for Myotis species and brown-long-eared bats. As noted above, no bat roosts were identified within the footprint of the proposed WwTP. There is potential that the disturbance of bats due to lighting during the Construction Phase would have an indirect, significant adverse impact at the local level. The impact would be temporary and would persist for the duration of the Construction Phase.

Proposed Abbotstown Pumping Station

Common and soprano pipistrelle and brown long-eared bat were recorded foraging along the immature woodland bordering the south of the proposed Abbotstown pumping station lands. A low level of common and soprano pipistrelle and Myotis species activity was recorded in the mature woodland to the north-east, outside of the proposed Abbotstown pumping station site. The removal of immature woodland and mixed woodland of local value would result in the removal of bat foraging habitat and may reduce the available insect prey species and the feeding area for bats. The reduction of foraging habitat would have a direct significant adverse impact on bats at the local level. In the absence of mitigation, this impact would be permanent and irreversible.

Lighting can cause avoidance of an area for commuting bats and can prevent or reduce foraging for Myotis species and brown long-eared bats. There is potential that the disturbance of bats due to lighting during the Construction Phase would have an indirect, significant adverse impact at the local level. The impact would be temporary, and would persist for the duration of the Construction Phase.

Proposed Orbital Sewer Route (Blanchardstown to Clonshagh) and Proposed Outfall Pipeline Route (Land Based Section) (Clonshagh to Baldoyle)

Common and soprano pipistrelle were recorded foraging and commuting throughout the proposed orbital sewer route and along the mature hedgerows present in the Kinsealy area. Leisler’s bat was recorded commuting overhead throughout the proposed orbital sewer route and outfall pipeline route (land based section). Brown long-eared bat, whiskered/Brandt’s bat, Daubenton’s bat and Myotis species of bat were all recorded in the Blanchardstown area, and a single brown long-eared bat call was recorded adjacent to a hedgerow at Kinsealy (see Section 11.3.3 for further details).

The Proposed Project Construction Phase works will require the removal of sections of hedgerows, immature woodland and (mixed) broadleaved woodland of local value. Loss of treelines and hedgerows or other linear features during construction will impact on commuting and foraging bats. The removal of foraging and commuting habitat would have a direct and significant adverse impact on bats at the local level. In the absence of mitigation, this impact would be permanent and irreversible. Loss or fragmentation of foraging habitats (such as hedgerows, treelines and woodlands) may reduce the available insect prey species and the feeding area for bats in some locations. The reduction of foraging

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habitat would have a direct, significant adverse impact on bats at the local level. In the absence of mitigation, this impact would be permanent and irreversible.

Loss of mature trees within hedgerows and mixed woodland may reduce potential roosting sites for individual bats. No bat roosts were identified within the Proposed Project boundary. However, occupation of roosts in trees by bats may be very transient, and there is potential that the mature broadleaf trees in the footprint of the proposed orbital sewer route may be used occasionally as roosting or resting places by individual/small numbers of bats. Therefore, there is potential for significant direct adverse impacts to individual bats as a result of the removal of mature broadleaf trees during the Construction Phase. This would be significant at the local level.

One mature sycamore and two mature oak trees have been identified as probable roosts for individual/small numbers of bats at Blanchardstown. The sycamore tree is directly adjacent to the proposed orbital sewer route construction corridor, and the two oak trees are approximately 21m to 25m to the north-west of the proposed orbital sewer construction corridor. There is potential that the disturbance of bats due to lighting during the Construction Phase would have an indirect, significant adverse impact at the local level. The impact would be temporary, and would persist for the duration of the Construction Phase.

11.4.4 Mammals (Other than Bats) No likely or significant impacts are predicted upon any ground mammals other than badgers. Section 23(5)(d) of the Wildlife Act 1976 (as amended) makes it an offence to wilfully interfere with or destroy the breeding place of any protected wild animal, including badger.

Three setts out of a total of eight setts identified in the survey area (S4, S5 and S6) are located sufficiently far from the Proposed Project boundary (90m, 70m and 40m respectively) that Construction Phase disturbance to those setts is not expected to occur.

Two badger setts (S2 and S3) are in very close proximity to the Proposed Project boundary, and Construction Phase activities are likely to cause disturbance to badger occupying these setts. S2 is active, located within the proposed construction corridor. S3 is disused and located within the proposed construction corridor. Setts S2 and S3 are both located on the northern side of the Proposed Project, and their foraging grounds extend both to the north and the south of the Proposed Project boundary and proposed 20m wayleave. A Wildlife Act disturbance licence will be obtained to temporarily close these badger setts during construction. Neither sett is a main breeding sett or an annex sett to a main breeding sett. Three setts (S1, S7 and S8) are within or in such close proximity to the Proposed Project boundary that they will be directly impacted upon during construction and must be closed under licence. These setts will be permanently closed prior to the commencement of construction. A Wildlife Act disturbance licence will be obtained to permanently close these badger setts during construction. These setts are either disused or long abandoned. Further, none of the setts have been characterised as a main breeding sett or an annex sett to a main breeding sett. The main breeding setts in each territory were not located during surveys. As such, it is considered that the main breeding setts are located at the least 100m from the Proposed Project boundary and therefore will not be impacted by the construction of the Proposed Project. The affected badger groups whose territories include land in the Proposed Project boundary will have a temporary boundary fence erected at the proposed construction corridor within their territories and through part of their foraging areas. The animals are principally nocturnal and construction activities will be principally undertaken during the daytime. The proposed construction corridor will be fenced off as noted above. In the

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case of Sett S1 to Sett S7, the affected badger territories are enclosed on the south-east by the M50 Motorway. As the Proposed Project skirts the M50 Motorway, only a fraction of their territory will be affected by construction of the Proposed Project.

Lands within the Proposed Project boundary are normally available to animals to pass through and forage within, but they may be displaced from the proposed construction corridor for the duration of construction, either because a fence prevents them accessing the land (without the animals digging under), or badger may choose to avoid foraging in these areas. Open pipes, excavations and/or trenches within the proposed construction corridor present a risk to foraging animals which could become trapped within them.

In the absence of mitigation, foraging habitats will be temporarily lost or present additional risks of entrapment to animals which venture into them. The overall impact is moderate adverse. This is significant. The three setts to be permanently closed under licence (S1, S7 and S8) are disused. Setts S2 and S3 require temporary closure under licence. Setts S4, S5 and S6 shall not be impacted upon by construction. No main breeding setts within any territory will be affected. In the absence of mitigation, badger setts would be disturbed or destroyed and an offence under wildlife law would occur. This is a moderate adverse impact and significant.

11.4.5 Farmland Birds The key construction impacts of the Proposed Project relevant to farmland birds are the potential for disturbance to nesting birds and damage to their nests. The works are short-term and disturbance impacts will be localised. In respect of the proposed orbital sewer route, outfall pipeline route (land based section) and terrestrial components of the proposed outfall pipeline route (marine section), together with the associated proposed temporary access tracks and proposed temporary construction compounds, the great majority of habitat comprises highly modified and intensively farmed agricultural landscapes (refer to Section 11.3.2 describing results of the habitat survey). These open fields support bird interests of local significance throughout the year. Farmland bird habitat will be lost in the short-term. Land will subsequently be reinstated. The overall impact is minor adverse. This is not significant.

In the case of the proposed WwTP site and the proposed Abbotstown pumping station site, there will be the permanent loss of habitat, although the great majority of this is again, characteristically, intensively farmed fields chiefly of local importance (lower value) (see Section 11.4.2 above).

Removal of habitats that do support breeding birds will occur, leading to some loss of nesting habitat and feeding opportunities. Birds will be displaced to alternative nesting habitat in the wider area beyond the Proposed Project boundary in the short-term. The overall impact is minor adverse. This is not significant.

Accidental destruction of nests or disturbance of nests could occur during the Construction Phase in the breeding season. This would be a moderate adverse impact and is significant. Mitigation is required.

11.4.6 Other Species Groups Smooth Newt

A series of ponds occur in the recolonising bare ground habitat at Coldwinters. Smooth newt was confirmed to be present in waterbodies here in both 2015 and 2017. In 2015, five ponds were located within the Proposed Project boundary. In response to 2015 survey findings, the Proposed Project boundary was modified to avoid three of the ponds. Now, only two ponds (11 and 15) occur within or on the Proposed Project boundary and in which newts were recorded in 2017.

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The core breeding pools/ponds (including the largest pond seen to retain water year-round) will be avoided. No significant impact is predicted upon the local population of this protected species as a result of the Proposed Project. However, in the absence of any special measures taken to avoid mortality of any individuals of a protected species, these ponds used by smooth newt (ascribed a local value) would be disturbed or destroyed. This is a moderate adverse impact and is significant.

11.5 Impact of the Proposed Project on Terrestrial Biodiversity – Operational Phase The normal operation of the Proposed Project and its constituent elements will be fully automated, which will be monitored, controlled and managed from a control centre located at the proposed WwTP.

The automated control systems will report through supervisory control and data acquisition and telemetry systems to the control centre. The proposed WwTP will be manned 24 hours a day, seven days a week. Between 30 and 40 operations staff will be employed, working in normal shift patterns, to ensure the continued and efficient operation of all elements of the Proposed Project.

Normal operational activities would typically include general maintenance, periodic inspections and monitoring of influent and treated wastewater discharges, sludge/septage imports and biosolids produced, depth of flow in the proposed orbital sewer route and outfall pipeline route (land based section and marine section) and pressure in the pumped rising mains amongst other things.

Potentially significant Operational Phase impacts are summarised in Table 11.15 and described thereafter.

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Table 11.15: Potentially Significant Operational Stage Impacts of the Proposed Project on Terrestrial Biodiversity

Feature Value Potential Impacts During Operational Phase

Habitat Loss, Deterioration and Disturbance to or Displacement of Protected Fragmentation Species or Reduction in Habitat Availability European International No impact. No impact. Sites, their importance There will be no direct or indirect loss, There will be no direct or indirect disturbance to buffer zones deterioration or fragmentation of terrestrial or displacement of terrestrial protected species, and the habitats for which these sites have been or reduction in terrestrial habitat availability to UNESCO designated. Marine habitats are assessed in protected species for which these sites have Biosphere EIAR Chapter 9 Biodiversity (Marine) and the been designated. Impacts on marine species Reserve NIS. are assessed in EIAR Chapter 10 and the NIS. Inland NHAs National No impact. No impact. importance There will be no direct or indirect loss, There will be no direct or indirect disturbance to deterioration or fragmentation of terrestrial or displacement of terrestrial protected species, habitats for which terrestrial pNHAs have been or reduction in terrestrial habitat availability to designated. pNHAs with marine habitats are protected species for which any terrestrial assessed in EIAR Chapter 9. pNHA sites have been designated. Impacts on marine species are assessed in EIAR Chapter 9 Biodiversity (Marine) and Chapter 10 Biodiversity (Marine Ornithology) and the NIS. NDAs County No likely significant impact. No impact. importance NDAs have been identified to provide Not applicable as NDAs are not designated in opportunities for habitat improvement. A the FDP (FCC 2017) for the occurrence of proposed 20m wayleave through the NDA does protected species not prevent those opportunities arising. GS2 Local No impact. Not applicable grassland importance The operation of the project will not result in any (higher value) ongoing impacts to areas of dry meadows and grassy verges. GS4 Local No impact. Not applicable grassland importance The operation of the project will not result in any (higher value) ongoing impacts to areas of wet grassland. (Mixed) Local No impact. Not applicable broadleaved importance The operation of the project will not result in any woodland, (higher value) ongoing impacts to areas of (mixed) scrub, broadleaved woodland, scrub, hedgerows and hedgerows treelines. and treelines Fixed dune Local No impact. Not applicable habitat at importance The operation of the project will not result in any Portmarnock (higher value) ongoing impacts to areas of fixed dune habitat. GA1 and Local No impact. Not applicable GA2 importance The operation of the project will not result in any grasslands, (lower value) ongoing impacts to areas of grasslands, spoil spoil and and recolonising bare ground, arable crops, recolonising horticultural land and tilled land. bare ground, arable crops, horticultural land and tilled land Bats Local Not applicable No likely significant impact. importance No direct impacts on roosting, commuting or

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Feature Value Potential Impacts During Operational Phase

Habitat Loss, Deterioration and Disturbance to or Displacement of Protected Fragmentation Species or Reduction in Habitat Availability (higher value) foraging bats. No further nesting habitat will be removed during operation and no further displacement will occur. Farmland Local Not applicable No likely significant impact. birds importance No direct impacts on farmland birds. (higher value) No further roosting, commuting or foraging habitat will be removed during operation and no further displacement will occur. Smooth newt Local Not applicable No likely significant impact. importance No direct impacts on newts are likely at occur at (higher value) operational stage. No further pond habitat will be removed during operation and no further displacement will occur. Otters Local Not applicable No impact. importance No direct or indirect impacts on any features (higher value) identified as being used by otters shall be affected at operational stage. Badgers Local Not applicable No likely significant impact. importance No direct impacts on badgers are likely at occur (higher value) at operational stage. No further sett disturbance will occur during operation and no further displacement will occur.

11.5.1 Designated Sites European Sites No component or aspect of the Proposed Project is to be located within any habitat above the mean high- water mark (i.e. a terrestrial habitat) which is part of a European Site. No Annex I habitat for which the Baldoyle Bay SAC has been designated occurs at proposed temporary construction compound no. 10 on the Portmarnock Peninsula. Chapter 9 Biodiversity (Marine) and Chapter 10 Biodiversity (Marine Ornithology) set out an impact assessment of the Operational Phase of the Proposed Project on European Sites, as their Qualifying Interests and SCIs correspond to ecological features falling under Chapter 9 Biodiversity (Marine) and Chapter 10 Biodiversity (Marine Ornithology) respectively.

Other Designated Areas

No component or aspect of the Proposed Project is proposed to be located within any terrestrial NHA or pNHA.

There will be no impacts on designated areas during the Operational Phase.

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11.5.2 Terrestrial Habitats All Elements of the Proposed Project As there is no requirement for any additional land-take during the Operational Phase, there will be no further loss of habitat after the Construction Phase. As such, there are no direct or indirect impacts on terrestrial habitats anticipated during the Operational Phase.

11.5.3 Bats Proposed Wastewater Treatment Plant and Proposed Abbotstown Pumping Station

There is potential for disturbance to bats due to lighting of the proposed WwTP during the hours of darkness. As detailed in Appendix A11.1, bats’ eyesight works best in dim light conditions; where there is too much luminance, bats’ vision can be reduced resulting in disorientation. Disturbance of bats due to lighting would have an indirect, significant adverse impact at the local level. Former semi-natural habitats at the proposed Abbotstown pumping station and the proposed WwTP will remain unavailable. Proposed Orbital Sewer Route (Blanchardstown to Clonshagh) and Proposed Outfall Pipeline Route (Land Based Section) (Clonshagh to Baldoyle)

After land reinstatement, habitats along the proposed orbital sewer route and outfall pipeline route (land based section) within the Proposed Project boundary will be available for bats foraging and commuting within their territories. Hedgerow replanting will re-establish ecological corridors which will be maintained throughout the Operational Phase. There is no requirement for any additional land-take during the Operational Phase, and there will be no further loss of habitat after the Construction Phase. There are no anticipated operational activities giving rise to visual stimuli likely to disturb bats. As such, there are no direct or indirect impact on bats anticipated during the Operational Phase.

11.5.4 Mammals (Other than Bats) After land reinstatement, habitats along the proposed pipeline routes within the Proposed Project boundary will be available for ground mammal foraging within their territories. Former semi-natural habitats at the proposed Abbotstown pumping station and the proposed WwTP will remain unavailable. Hedgerow replanting will re-establish ecological corridors which will be maintained throughout the Operational Phase. There is no requirement for any additional land-take during the Operational Phase, and there will be no further loss of habitat after the Construction Phase. There are no anticipated operational activities giving rise to noise or visual stimuli likely to disturb ground mammals. As such, there are no direct or indirect impacts on other mammals anticipated during the Operational Phase.

11.5.5 Farmland Birds After land reinstatement, habitats along the proposed pipeline routes within the Proposed Project boundary will be available for farmland birds to forage and build nests their territories. Former semi-natural habitats at the proposed Abbotstown pumping station and the proposed WwTP will remain unavailable. Hedgerow replanting will re-establish ecological corridors which will be maintained throughout the Operational Phase. There is no requirement for any additional land-take during the Operational Phase, and there will be no further loss of habitat after the Construction Phase. There are no anticipated operational activities giving rise to noise or visual stimuli likely to disturb farmland birds. As such, there are no direct or indirect impacts on farmland birds anticipated during the Operational Phase.

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11.5.6 Other Species Groups After land reinstatement, habitats where smooth newts were recorded along the proposed pipeline routes within the Proposed Project boundary will be available for smooth newts to hold territories. Ponds where newts are to be relocated will not be affected. There is no requirement for any additional land-take during the Operational Phase, and there will be no further loss of suitable newt habitat after the Construction Phase. There are no anticipated operational activities likely to disturb smooth newts. As such, there are no direct or indirect impacts on smooth newts anticipated during the Operational Phase.

11.6 ‘Do Nothing’ Impact on Terrestrial Biodiversity Not constructing and operating the Proposed Project would result in terrestrial flora and fauna along the Proposed Project persisting under its current land use and management regimes. The impact of such a course of action is neutral upon terrestrial biodiversity features near the Proposed Project.

11.7 Mitigation Measures – Terrestrial Biodiversity Where the assessment of impacts has concluded that there are no significant effects, it is considered that no mitigation is required. and therefore no mitigation is proposed, in accordance with Section 11.2.4.

11.7.1 Overarching Measures All Proposed Project Elements An Ecological Clerk of Works (ECoW) will be appointed by Irish Water to advise on effective implementation of biodiversity mitigation specified in the EIAR, NIS and the Outline CEMP, and to act as a liaison between Irish Water and ABP in the discharge of planning conditions relating to biodiversity. The ECoW shall be supported by other specialist ecologists as necessary to ensure effective implementation of biodiversity mitigation.

Tool-box talks will be provided for the appointed contractor(s), subcontractors and operatives on their legal obligations in relation to wildlife legislation, and good practice in relation to construction and protected species.

Tool-box talks will be provided by the ECoW in consultation with the appointed Environmental Manager of the main appointed contractor(s), prior to the commencement of the Construction Phase.

11.7.2 Designated Sites (All Proposed Projects Elements) Construction Phase

No mitigation is proposed. Operational Phase

No mitigation is proposed.

11.7.3 Terrestrial Habitats Construction Phase Proposed Wastewater Treatment Plant

All hedgerows removed during the Construction Phase shall be replaced.

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Planting of native hedgerow and perimeter screening with native species of trees will be implemented as part of the landscape strategy presented in Chapter 12 Landscape and Visual.

Proposed Abbotstown Pumping Station

No mitigation is proposed. Proposed Pipeline Routes Including All Proposed Temporary Construction Compounds

Grassland sward along the proposed construction corridor will be reinstated.

Sections of hedgerows and treelines which are removed to facilitate construction will be replanted. Topsoil shall be retained from wet grassland and neutral grassland habitats subject to topsoil stripping and will be reused for reinstatement in its original location.

Operational Phase No mitigation is proposed.

11.7.4 Bats Construction Phase

Proposed Wastewater Treatment Plant Loss or Fragmentation of Habitat

Hedgerow removal will create a barrier and reduce the foraging area for foraging and commuting bats during the construction of the proposed WwTP. This will be mitigated by the landscape proposed, which include the planting of hedgerow, specimen trees and wildflower meadow to the north, east and west of the proposed WwTP site (refer to Chapter 12 Landscape and Visual, Section 12.7 for further details).

Loss of Potential Roost Sites

In order to protect potential roost sites, any existing mature trees adjacent to the Proposed Project or construction areas which will not be removed shall be protected from root damage in accordance with BS 5837:2012 Trees in relation to design, demolition and construction (British Standards Institution 2012) as part of the construction contract.

Mature standard trees within the hedgerows to be cleared at the proposed WwTP site shall be felled in the period from late August to late October, or early November, in order to avoid the disturbance of any roosting bats as per the Guidelines for the Treatment of Bats Prior to the Construction of National Road Schemes (NRA 2005a). During this period bats, are still capable of flight having not entered hibernation, and undertaking works in this period may reduce the risks of tree-felling if proper measures are undertaken. Once felled, trees that have potential bat roost features shall be left intact on-site for 24 hours prior to disposal to allow any bats to escape overnight.

Tree roosts may be established for short periods and may not be detectable when bats are not occupying the roost from an examination of a suitable tree. Furthermore, trees may become suitable for roosting bats through damage from storm, machinery, rot or human interference. Therefore, trees that are at present unsuitable may become roosts between the pre-planning assessment contained within this EIAR and the Construction Phase of the Proposed Project. All trees within the boundary of the Proposed Project shall be checked for Potential Roost Features (PRFs) by an experienced bat ecologist as part of a pre-construction survey.

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Resulting from the pre-construction PRF survey, all trees with medium to high roost potential shall be examined by an experienced bat ecologist reporting to the ECoW prior to work commencing by any appointed contractor(s) or subcontractors on any part of the Construction Phase (including enabling works) of the Proposed Project, including fencing, vegetation clearance or topsoil stripping. Following this examination, should any tree be identified as a bat roost then a derogation licence application will be made to exclude the bats and fell the tree. The roost must not be altered or affected in any way prior to works being undertaken as stipulated within the derogation licence and using the measures stipulated in the licence for the exclusion of bats and felling must be carried out under the supervision of a bat specialist named on the licence.

The loss of PRFs in trees as a result of vegetation clearance will necessitate the installation of bat boxes to compensate for potential roost loss. Bat boxes will be installed at least three months in advance of removal of existing potential roosting sites. One box per tree with moderate to high bat suitability scheduled to be felled will be installed by the appointed contractor(s); the appropriate number of bat boxes to compensate for loss of potential roosting features will be finalised following pre-construction PRF inspection presence/absence surveys. The boxes will be attached to suitable trees in hedgerows, treelines and woodland along the route but outside the area of clearance. The final box locations will be confirmed on-site with the bat specialist. The principal recommended type along the proposed pipeline routes is the Schwegler 1FF bat box. Boxes shall be erected in pairs and all boxes placed in sites that will be protected from disturbance. These boxes must be away from any felling or trimming to ensure that they are not accidentally damaged or removed. Bat boxes must be clear of scrub and away from ivy encroachment as well as lighting and traffic. Monitoring

It is essential to monitor boxes for their acceptance of use by bats, and those boxes that remain unused two years after the date of erection should be relocated. Seasonal inspection of bat boxes shall be undertaken (excluding mid-June to mid-August, the lactation period of females, where any disturbance at this time can be detrimental to the survival of young) to monitor bat usage and in wintertime for general wear and tear and to remove droppings following use the previous summer. This should be undertaken by a licensed bat-handler (NRA 2005a).

Light Pollution

Where construction lighting is required, lighting will be directed away from all woodland, hedgerow and linear habitats. Directional lighting (i.e. lighting which only shines on the Proposed Project and not on the nearby countryside) will be used to prevent overspill. This will be achieved by the design of the luminaire and by using accessories such as hoods, cowls, louvres and shields to direct the light to the intended area only. Proposed Abbotstown Pumping Station

Loss or Fragmentation of Habitat

The loss of foraging and commuting habitat as a result of the removal of immature and mixed broadleaved woodland for construction of the proposed Abbotstown pumping station will be mitigated by planting schemes utilising advanced nursery stock.

Light Pollution

Where construction lighting is required, lighting will be directed away from all woodland, hedgerow and linear habitats to be retained. This can be achieved by the use of directional lighting to prevent overspill.

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Proposed Orbital Sewer Route (Blanchardstown to Clonshagh) Loss or Fragmentation of Habitat

The loss of foraging and commuting habitat as a result of hedgerow and treeline removal for construction will be mitigated by replacement and replanting. Where feasible, trees and hedgerows disturbed by the construction works will be re-instated. Depending on the season in which construction work takes place, it may be possible to store and replace sections of dormant hedgerows once work in a particular section is complete. Where this is not practicable, new planting will take place utilising advanced nursery stock. Loss of Potential Roost Sites

Mitigation as per measures provided for loss of potential roost sites at the proposed WwTP.

Light Pollution

Where construction lighting is required, lighting will be directed away from all woodland, hedgerow and linear habitats to be retained. This can be achieved by the use of directional lighting.

There will be no direct illumination of known bat roosts. Lights will be positioned to avoid sensitive areas and restricted so that there are dark areas. When works are conducted adjacent to known or potential bat roosts (as identified in Figure 3.5 of the Bat Survey Report at Appendix A11.1, the timing of lights shall be restricted to avoid bat activity (i.e. from dusk until dawn). Proposed Outfall Pipeline Route (Land Based Section) (Clonshagh to Baldoyle)

Loss or Fragmentation of Habitat

Mitigation as per measures provided for loss or fragmentation of habitat for the proposed orbital sewer route. Loss of Potential Roost Sites Mitigation as per measures provided for loss of potential roost sites at the proposed WwTP. Light Pollution Mitigation as per measures provided for light pollution for the proposed orbital sewer route. Operational Phase

Proposed Wastewater Treatment Plant

Landscaping treatment for the proposed WwTP includes planting of hedgerow, specimen trees and wildflower meadow to the north, east and west of the proposed WwTP site. Lighting will be minimised in these areas, and the times during which the lighting is on will be limited to provide some dark periods. Should security lighting be necessary, directional lighting will be used to prevent overspill. Proposed Abbotstown Pumping Station

No significant impacts have been identified; therefore, no mitigation is proposed.

Proposed Orbital Sewer Route (Blanchardstown to Clonshagh) No significant impacts have been identified; therefore, no mitigation is proposed.

Proposed Outfall Pipeline Route (Land Based Section) (Clonshagh to Baldoyle)

No significant impacts have been identified; therefore, no mitigation is proposed.

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11.7.5 Mammals (Other than Bats) Construction Phase Proposed Orbital Sewer Route Including Proposed Abbotstown Pumping Station

In order to ensure there are no significant changes to the badger territory’s identified in the EIAR and the mitigation measures specified, a pre-construction badger survey should be undertaken prior to the commencement of any works.

A wildlife disturbance licence will be obtained from NPWS for the exclusion and closure (two temporarily and three permanently) of five badger setts identified within the Proposed Project boundary.

The licence application will be made by the appointed ECoW, who will conduct or otherwise supervise all licensed activities.

All works under licence will be monitored as necessary by the appointed ECoW throughout the Construction Phase.

Setts closed for the duration of the Construction Phase shall be re-opened at the earliest opportunity in consultation with the licencing authority. An Ecological Exclusion Zone will be set up around setts S2 and S3 at a radius of 25m to protect them from construction activities, facilitating their re-opening after the Construction Phase is complete. The Ecological Exclusion Zone fence will keep appointed contractor(s) out of the Ecological Exclusion Zone, and warning signs will be erected at intervals on the fence. No vehicles, storage or stockpiling of materials will be allowed within the Ecological Exclusion Zone. An ECoW will supervise the erection of each Ecological Exclusion Zone and inspect it regularly to ensure that it is in working condition and functioning as required. The specification of the temporary fence for the proposed construction corridor will allow unimpeded movement of badger at the bottom of the fence so they can continue to move within their territorial boundaries. Open excavations and/or trenches will either be covered to avoid access by wildlife or a means of escape installed to facilitate egress at the end of each working day. All pipes will be capped overnight to prevent access by mammals. Operational Phase

No mitigation is proposed.

11.7.6 Farmland Birds Construction Phase All Proposed Project Elements

Grassland sward along the proposed construction corridor will be reinstated.

Sections of hedgerows and treelines which are removed to facilitate construction will be replanted. Vegetation clearance and topsoil stripping will be programmed to be undertaken outside of the breeding bird season between 1 March and 31 August.

If any small pockets of vegetation must be cleared within the breeding season, due to circumstances beyond the control of the applicant, then an experienced ornithologist, appointed by Irish Water or its agents, will report to the ECoW and inspect the vegetation to check for breeding birds.

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These checks will be done no more than three days ahead of the required clearance, and if a nest is found, suitable buffers will be cordoned off and clearly marked. The ECoW shall ensure that no works including fencing, vegetation clearance or topsoil stripping shall occur within a cordoned area.

Nest boxes and nest cavities shall be incorporated into the building design of the proposed Abbotstown pumping station and proposed regional WwTP.

Operational Phase (All Proposed Project Elements)

No mitigation is proposed.

11.7.7 Other Species Groups Construction Phase

Proposed Orbital Sewer Route

A disturbance licence shall be obtained from NPWS. Smooth newts shall be captured at Coldwinters under licence during the spring migration period.

Smooth newts shall be relocated from affected ponds to an alternative pond at Coldwinters prior to the commencement of construction. All works under licence will be monitored as necessary by the appointed ECoW throughout the Construction Phase. The pond within the Proposed Project boundary from which newts are removed must be drained down and remain unavailable to smooth newts throughout the Construction Phase until the land is reinstated. Operational Phase

No mitigation is proposed.

11.8 Residual Impacts – Terrestrial Biodiversity An assessment of residual impacts identifies the impacts associated with the Proposed Project and the likely significance of impacts on the environment and its ecological features after the implementation of mitigation measures. With the successful implementation of mitigation measures outlined within Section 11.7, no significant residual impacts on terrestrial biodiversity features are predicted, as summarised in Table 11.16.

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Table 11.16: Residual Impacts of the Proposed Project on Terrestrial Biodiversity

Feature Value Residual Impacts During Construction Phase Residual Impacts During Operational Phase

Habitat Loss, Disturbance to or Habitat Loss, Disturbance to or Deterioration and Displacement of Protected Deterioration and Displacement of Protected Fragmentation Species or Reduction in Fragmentation Species or Reduction in Habitat Availability Habitat Availability

European Sites, their buffer zones International importance Not significant Not significant Not significant No impact and the UNESCO Biosphere Reserve Inland NHAs National importance No impact No impact No impact No impact

NDAs County importance Not significant No impact Not significant No impact GS2 grassland Local importance (higher value) Not significant Not applicable No impact Not applicable GS4 grassland Local importance (higher value) Not significant Not applicable No impact Not applicable (Mixed) broadleaved woodland, Local importance (higher value) Not significant Not significant No impact Not significant scrub, hedgerows and treelines Fixed dune habitat at Local importance (higher value) No impact Not applicable No impact Not applicable Portmarnock GA1 and GA2 grasslands, spoil Local importance (lower value) Not significant Not applicable No impact Not applicable and recolonising bare ground, arable crops, horticultural land and tilled land Bats Local importance (higher value) Not applicable Not significant Not applicable Not significant Farmland birds Local importance (higher value) Not applicable Not significant Not applicable Not significant Smooth newt Local importance (higher value) Not applicable Not significant Not applicable Not significant Otters Local importance (higher value) Not applicable No impact Not applicable No impact Badgers Local importance (higher value) Not applicable Not significant Not applicable Not significant

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11.8.1 Difficulties Encountered in Compiling Required Information For the terrestrial flora and fauna surveys, there were a small number of locations along the Proposed Project where access permission could not be secured for the suite of ecological surveys undertaken. These areas were small, discrete, visible from distance and/or from adjoining lands where access was permitted and were generally comparable in nature to other habitats.

11.9 Baseline Environment – Freshwater Aquatic Biodiversity The proposed orbital sewer route will commence in the townland of Abbotstown, where the proposed Abbotstown pumping station will be located, approximately 130m from the Tolka River (survey location 1, see Figure 11.17 Freshwater Sampling Locations). This site has a footprint of approximately 4,000m3. Travelling in an easterly direction, the proposed orbital sewer route will cross the Santry River (survey location 2) in the townland of Silloge, followed by the Mayne River (survey location 3) in the townland of Ballystruan before entering the proposed WwTP at Clonshagh. The northern boundary of the proposed WwTP at Clonshagh, located on a 29.8ha site, is set back 50m from the Cuckoo Stream, a tributary of the Mayne River. A SHC will also be co-located at this site, while the proposed NFS diversion sewer will also be connected to the proposed WwTP. On exiting the proposed WwTP, the proposed outfall pipeline route (land based section) will cross the Cuckoo Stream (survey location 4). A proposed access road will be constructed from the R139 Road to the proposed WwTP, and this will require the installation of a culvert and widening of the bridge over the Mayne River, currently leading to Craobh Chiaráin Gaelic Athletic Association (GAA) pitches (survey location 5). All watercourse crossings are identified on Figure 11.17 Freshwater Sampling Locations.

Catchment Description The Tolka River rises near Dunshaughlin in Co. Meath and flows in a south-easterly direction where it crosses through the north of Dublin City before entering the sea at Clontarf through South Dublin Bay and the River Tolka Estuary SPA (004024) and North Dublin Bay pNHA (000206). The Tolka River has a length of approximately 20km from source to the sea, nearly half of which is located within the urban sprawl of Dublin City. The Tolka River will not be crossed by the proposed orbital sewer route; however, the proposed Abbotstown pumping station will be located approximately 130m from the Tolka River. The course of the Tolka River has been altered in this location and flows in a straight line under the M50 Motorway within an artificial channel with concrete banks.

The Santry River rises near Harristown, in Co. Dublin, and flows east via Santry, Kilmore, Edenmore and Raheny, through several designated nature conservation areas, before entering the sea at Dublin Bay. The Santry River flows through the Santry Demesne pNHA (00178) and discharges through North Bull Island SPA (004006) and North Dublin Bay SAC and pNHA (000206). The Santry River will be crossed once by the proposed orbital sewer route at Silloge. Proposed temporary construction compound no. 3 will be located at the M50 Motorway Junction 4, and will be located approximately 100m from this river.

The Mayne River rises near Harristown, in Co. Dublin, and flows east, entering the sea via Portmarnock Estuary at Mayne Bridge. The Cuckoo Stream, a tributary of the Mayne River, rises near Huntstown, in Co. Dublin, and flows east, merging with the Mayne River at Balgriffin. The Mayne River discharges through Baldoyle Bay SAC and pNHA (000199) and Baldoyle Bay SPA (004016). The Mayne River will be crossed once by the proposed orbital sewer route just north of the M50 Motorway and south of Ballystruan. Proposed temporary construction compound no. 4 will be located at the Old Airport Road/R132 Swords Road junction (the Collinstown Cross) and will be located approximately 650m from the Mayne River and approximately 235m from the Cuckoo Stream. The Mayne River will also be crossed by a new culvert system which will be

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constructed to provide access to the Craobh Chiaráin GAA pitches and the proposed WwTP at Clonshagh. The Cuckoo Stream will be crossed once by the proposed orbital sewer route directly downstream of the proposed WwTP which will be constructed at Clonshagh. The Cuckoo Stream also lies immediately north of the proposed WwTP site, while the Mayne River lies approximately 400m to the south. The site of the proposed WwTP will also house temporary construction compound no. 5 for the duration of the Construction Phase.

Other designations of relevance have been presented in Section 11.3.1 of this Chapter. Water Quality

The EPA Catchments website (EPA 2017) identifies the current ecological status of the Tolka River, Santry River, Mayne River and Cuckoo Stream near the Proposed Project being Poor (refer to Table 11.17 below). The EPA biological water quality monitoring data indicate that all three rivers have suffered from pollution problems since monitoring commenced in 1973 for the Tolka River and 1988 for the Santry River and the Mayne River. All three rivers and the Cuckoo Stream are classified as ‘at risk’ of failing to achieve the environmental objectives of the Draft River Basin Management Plan for Ireland 2018–2021 (DoHPLG 2017) and therefore will require significant measures to improve their condition.

Table 11.17: Condition of Rivers Crossed by the Proposed Project

River Overall Status2 Overall Risk Q-Value3 Fisheries Status4 Heavily Modified* Tolka Poor At risk Q3 Poor (2011) No Santry Poor At risk Q3 Not surveyed by IFI Yes Mayne Poor At risk Q3 Poor (2016) No Cuckoo Stream Poor At risk Not surveyed by Bad (2016) No EPA *Heavily modified waterbodies have been substantially altered from their natural condition by human activity and cannot therefore attain Good ecological status. Heavily modified waterbodies have targets relating to their ecological potential. Designated Areas and Protected Species (Existing Records) The land based elements of the Proposed Project are not within the footprint of any site designated for nature conservation, as outlined in Section 11.3.1. The proposed outfall pipeline route (marine section) of the Proposed Project will pass under Baldoyle SAC and Baldoyle SPA and is discussed further in Chapter 9 Biodiversity (Marine).

The land based elements of the Proposed Project intersect three watercourses (Mayne River, Santry River and Cuckoo Stream) and are near to a fourth (Tolka River). These are the aquatic Ecological Receptors (AERs) potentially impacted by the Proposed Project. Via the ERs, the Proposed Project is hydrologically connected to several downstream Natura 2000 sites (see Chapter 9 Biodiversity (Marine)). These include eight SACs and eight SPAs. Interactions between the Proposed Project and Natura 2000 sites are considered in greater detail in the NIS for the Proposed Project.

The Proposed Project is not within the footprint of any NHAs or pNHA sites. Table 11.18 below lists the NHAs and details on their supporting connectivity to the Proposed Project. The pNHAs numbered 3, 4, 5, 6 and 7 in Table 11.18 are marine locations and are considered in Chapter 9 Biodiversity (Marine).

2 Data sourced from www.catchments.ie, based on data from 2010 to 2015 (latest available and published survey data by the EPA). 3 Q-value for the river segment at the location of the crossing for the Santry, Mayne and at the proposed Abbotstown pumping station for the Tolka. There is no EPA monitoring station on the Cuckoo Stream. 4 Data sourced from www.wfdfish.ie, based on surveys undertaken in 2011 and 2016 by Inland Fisheries Ireland.

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Table 11.18: Proposed Natural Heritage Areas Supporting Connectivity to the Proposed Project

No. Site Site Name Distance (km) Qualifying Features Code

1 000128 Liffey 2.2 This site is part of the Liffey Valley Special Amenity Areas Order 1990 (SDCC Valley 2016). The site is important due to the diversity of the habitats within the site, both aquatic and terrestrial. A number of rare and threatened plant species have been recorded from the site. The Proposed Project is not connected to the Liffey Valley pNHA. Therefore, there will be no impact to this site. 2 000178 Santry 0.3 The primary importance of this site is that it contains a legally protected plant Demesne species. The woodland, however, is of general ecological interest as it occurs in an area where little has survived of the original vegetation. There is a hydrological connection to the Santry Demesne pNHA. However, this pNHA is designated for terrestrial woodlands which are not at risk of impact from the Proposed Project. 3 000199 Baldoyle 0.0 Mudflats and sandflats not covered by seawater at low tide (1140) Bay Salicornia and other annuals colonising mud and sand (1310) Atlantic salt meadows (Glauco-Puccinellietalia maritimae) (1330) Mediterranean salt meadows (Juncetalia maritimi) (1410) 4 000202 Howth 4.3 Vegetated sea cliffs of the Atlantic and Baltic coasts (1230) Head European dry heaths (4030) 5 000203 Ireland’s 3.4 Perennial vegetation of stony banks (1220) Eye Vegetated sea cliffs of the Atlantic and Baltic coasts (1230) 6 000206 North 2.3 Mudflats and sandflats not covered by seawater at low tide (1140) Dublin Bay Annual vegetation of drift lines (1210) Salicornia and other annuals colonising mud and sand (1310) Atlantic salt meadows (Glauco-Puccinellietalia maritimae) (1330) Mediterranean salt meadows (Juncetalia maritimi) (1410) Embryonic shifting dunes (2110) Shifting dunes along the shoreline with Ammophila arenaria (white dunes) (2120) Fixed coastal dunes with herbaceous vegetation (grey dunes) (2130) Humid dune slacks (2190) Petalophyllum ralfsii (Petalwort) (1395) 7 000210 South 7.3 Mudflats and sandflats not covered by seawater at low tide (1140) Dublin Bay Annual vegetation of drift lines (1210) Salicornia and other annuals colonising mud and sand (1310) Embryonic shifting dunes (2110) 8 001208 Feltrim Hill 1.2 Feltrim Hill is regarded as a good example of a knoll-reef and is a valuable geological education site. There is no connection between the Proposed Project and Feltrim Hill. 9 001763 Sluice 1.0 This site is of importance as a relatively intact freshwater marsh, a habitat that is River now rare in County Dublin. Marsh There is no connection between the Proposed Project and the Sluice River Marsh.

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No. Site Site Name Distance (km) Qualifying Features Code

10 002103 Royal 0.3 The value of the canal lies in the diversity of species it supports along its linear Canal habitats. It crosses through agricultural land and therefore provides a refuge for species threatened by modern farming methods. There is no connection between the Proposed Project and the Royal Canal pNHA. 11 002104 Grand 6.1 The ecological value of the canal lies in the diversity of species it supports along Canal its linear habitats and the presence of rare species. It crosses through agricultural land and therefore provides a refuge for species threatened by modern farming methods. There is no connection between the Proposed Project and the Grand Canal pNHA.

Protected Freshwater Species A review of the NBDC website (Biodiversity Ireland 2017) revealed no records for white-clawed crayfish, salmon or lamprey in any of the watercourses potentially impacted by the Proposed Project. IFI has confirmed that the Tolka River is an important salmonid river, and supports eel (Anguilla anguilla) and river lamprey. A review of the NPWS website (NPWS 2015) revealed no records of rare and protected freshwater species in the area of the Proposed Project. During macroinvertebrate surveys of the watercourses, no salmonids, lamprey or white-clawed crayfish were identified at any of the sampling locations. Low quality spawning habitat for salmonids and lamprey were recorded on the Tolka River and in the lower reaches of the Mayne River.

Fishery Value

The Tolka River (which is not crossed by the proposed orbital sewer route (refer to Figure 11.17 Freshwater Sampling Locations) is an important salmonid system under significant ecological pressure from urbanisation. One site was surveyed by IFI on the Tolka River in 2011 (IFI 2012) as part of the Irish WFD fish monitoring programme. The site was located downstream of the N2 National Road bridge, between the Violet Hill estate and Glasnevin Cemetery. A total of six species were recorded during the survey. Minnow (Phoxinus phoxinus) was the most abundant species, followed by three-spined stickleback (Gasterosteus aculeatus), lamprey (Lampetra sp.), eels (Anguilla anguilla), stone loach (Barbatula barbatula) and salmon (Salmo salar). This site was classified at Poor ecological status. However, the surveys confirmed the presence of salmon in this river for the first time in over 100 years, which indicates the potential for this river as a salmon fishery. Significant improvement in water quality would be required before a sustainable population can be established in the future5. IFI has also confirmed that this system supports a resident population of brown trout, a migratory population of sea trout, eels and river lamprey (Gretta Hannigan, IFI, pers. comm. 2015).

The Santry River is a non-salmonid system due to impassable features located at the lower end of the system (Gretta Hannigan, IFI 6 , pers. comm. 2015). There is no WFD fish monitoring undertaken on this river; however, a survey undertaken by IFI in 2013 found only five three-spined stickleback. Water quality is also under significant pressure due to urbanisation in the catchment, and the river has been significantly modified through culverting and channelization which has caused straightening and widening of the river channel.

The Mayne River and tributaries including the Cuckoo Stream are currently a non-salmonid system due to a combination of factors, namely impassable barriers and historically poor water and habitat quality. The Mayne River is included as part of the Irish WFD fish monitoring programme. The survey in 2011 at Wellfield Bridge surveyed 42m of channel consisting of pool, glide and riffles, and recorded only two fish species: three-spined

6 http://laetitiabeschus.weebly.com/uploads/2/8/4/3/28435135/santry_river_and_santry_woods.pdf

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stickleback (Gasterosteus aculeatus) and eels (Anguilla anguilla). The Mayne River was also surveyed at two sites in 20167, and three fish species were recorded: eel and three-spined stickleback were present at two sites surveyed, and flounder (Platicthys flesus) was found at one site due to the close proximity of the site to the sea. There was a reduced density of three-spined stickleback when compared with the 2011 survey at the Wellfield Bridge site. This represented deterioration in ecological status for the Mayne River at the Wellfield Bridge site, from Moderate ecological status in 2011 to Poor ecological status in 2016. The Snugborough site was also classified as Poor ecological status. The Cuckoo Stream (a tributary of the Mayne River) was surveyed by IFI in 2016. European eel was the only species recorded at the site surveyed at Limekiln Lane. The ecological status at this site was deemed to be Bad. It is the view of IFI that salmonid status (i.e. waters capable of supporting salmon and trout) could be regained on the river, and therefore IFI have sought and secured fish-friendly culverts when consulted with respect to developments (Gretta Hannigan, IFI, pers. comm. 2015).

Invasive Species The introduction and spread of invasive species can have significant impacts on the ecological functioning of watercourses. The following invasive species have been identified in the lower reaches of the Tolka River (Biodiversity Ireland 2017): Japanese knotweed (Fallopia japonica), giant hogweed (Heracleum mantegazzianum) and Himalayan balsam (Impatiens glandulifera). Japanese knotweed and giant hogweed are also present in the lower reaches of the Santry River (Biodiversity Ireland 2017). Giant rhubarb (Gunnera tinctoria M.) was recorded along the Tolka River downstream of the proposed orbital sewer route and the proposed Abbotstown pumping station during the freshwater surveys in 2015.

Drainage Ditches near the Proposed Project

Several drainage ditches, in addition to the above watercourses, will be crossed by the proposed orbital sewer route and the proposed outfall pipeline route (land based section) and within the proposed WwTP site. During surveys in the spring (February to April 2014), the drainage ditches were recorded as containing low water levels, and were either recently cleared as part of agricultural drainage maintenance or contained filamentous algal growth. These ditches had no fisheries habitat or potential to support fisheries habitat. These drainage ditches were not subject to macroinvertebrate sampling, as they were considered inappropriate for Q-value assessments. Further surveys of the drainage ditches were not deemed to be required on the basis of these findings.

11.9.1 Field Survey Results Habitats

Along the potentially affected watercourses (i.e. those near or crossed by the proposed orbital sewer route (land based section) or new culvert system), the habitat sections surveyed and the sites at which biological sampling was undertaken are shown in Figure 11.17 Freshwater Sampling Locations. One site, a tributary of the Tolka River between the back of Connolly Hospital and the N3 National Road which will be crossed by the proposed orbital sewer route, was not suitable for survey due to significant morphological alternations to its channel, which have impacted its aquatic characteristics. There were no suitable areas of this tributary within which a survey could be conducted. The Tolka River itself will not be crossed by the proposed orbital sewer route (lies south-west); however, it has salmonid potential. All other watercourses surveyed had limited salmonid potential. Salmonid spawning and nursery habitat of poor quality was recorded in some of the downstream sections surveyed, e.g. the Mayne River and Cuckoo Stream, and are known to be non-salmonid rivers/streams due to an impassable barrier to fish movement at the lower end of the system (Gretta

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Hannigan, IFI, pers. comm. 2015). Poor lamprey nursery habitats were present in the surveyed reaches, and lamprey spawning habitat was classified as poor quality.

Macroinvertebrate Biodiversity

Across the five sampled locations, macroinvertebrate diversity was generally low with six or fewer taxa identified at each location in 2015, and again in 2017 (refer to Table 11.19). The Mayne River (Location 5) had the highest number of taxa (six) and was the only location that had a sensitive taxon present in the 2015 survey (Ecdyonurus spp.). During the 2017 survey, no taxa considered sensitive were identified at any location. Each of the watercourses exhibited a community impacted by urbanisation, eutrophication and other pressures.

Table 11.19: Macroinvertebrate Community Composition from Sampled Watercourses

Habitat Site Macroinvertebrate Relative Abundance Relative Sensitivity to Organic Pollution Taxa List 2015 Abundance 2017 Location 1 – Chironomidae spp. Numerous None recorded Relatively tolerant Tolka River Gammaridae sp. Numerous None recorded Relatively tolerant but acid sensitive Hydrophsyce spp. Few None recorded Relatively tolerant Caenidae spp. Few None recorded Less sensitive Baetidae spp. Few None recorded Relatively tolerant but acid sensitive Location 2 – Gammaridae sp. Numerous Excessive Relatively tolerant but acid sensitive Santry River Ceratopogonidae spp. Few None recorded Relatively tolerant Simuliidae spp. Few None recorded Relatively tolerant Chironomidae spp. Few Few Relatively tolerant Hirudinea None recorded Few Tolerant Chironomus None recorded Few Tolerant Location 3 – Asellus sp. Numerous Common Very tolerant Mayne River Gammaridae sp. Numerous Excessive Relatively tolerant but acid sensitive Erpobdella Few None recorded Tolerant Chironomidae spp. Few Common Relatively tolerant Location 4 – Baetidae spp. Numerous Excessive Relatively tolerant but acid sensitive Cuckoo Stream Gammaridae sp. Numerous None recorded Relatively tolerant but acid sensitive Ephemerlla spp. Few None recorded Less sensitive Simuliidae None recorded Common Relatively tolerant Chironomidae spp. None recorded Few Relatively tolerant Chironomus sp. None recorded Few Tolerant Hirudinea sp. None recorded Few Tolerant Diptera Larvae None recorded Few Relatively tolerant Location 5 – Gammaridae sp. Numerous Excessive Relatively tolerant but acid sensitive Mayne River Chironomidae None recorded Scarce/Few Relatively tolerant Hirudinea sp. None recorded Scarce/Few Tolerant Asellus sp. None recorded Scarce/Few Very tolerant

Biological Water Quality Assessment The water quality survey of the invertebrate community (Q-values) in the potentially impacted watercourses ranged from Q2 (Bad ecological status) at the Santry River (Location 2) and Mayne River (Location 3) to Q3 (Poor ecological status) at the Cuckoo Stream (Location 4), with the Tolka River falling between Q2 and Q3 (Poor ecological status) (refer to Table 11.20 and Plate 11.1). All sites are indicative of low diversity communities of unsatisfactory condition and less than Good status.

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Freshwater Flora In-stream plant diversity was low across all sites surveyed, with only bulrush (Typha latifolia L.) and yellow iris (Iris pseudacorus L.) being recorded in the Tolka River. Bulrush was also recorded in the Santry River, and lesser water-parsnip (Berula erecta (Hudson) Coville) and fool’s watercress (Apium nodiflorum (L.) Lagasca) were recorded in the Mayne River. These species are common throughout Ireland (Preston and Croft 1997) and are often found in shallow water in nutrient rich sites.

Fish All the watercourses surveyed had limited salmonid potential, except for the Tolka River, due to the presence of impassable barriers to fish movement in the lower reaches of these systems.

Salmonid spawning and nursery habitat of poor quality were recorded in some of the downstream sections surveyed. Fair lamprey nursery habitat was recorded in some of the surveyed reaches, and the lamprey spawning habitat was classified as poor quality. The Tolka River contains suitable salmonid habitat and supports brown trout, sea trout and eels both upstream and downstream of the proposed Abbotstown pumping station, in addition to other fish species. Salmon have also recently been recorded from the lower reaches of the Tolka River system (IFI 2011).

Table 11.20 presents a description of the habitats and macroinvertebrate communities found at the sampling locations, together with information on fisheries value and the presence of Annex II Habitats Directive species. The ecological valuation for each identified AER is also presented.

Ecological Importance A total of four aquatic AERs were recorded within the ZoI of the Proposed Project. Table 11.20 provides a description of each of these AERs. The ecological valuation system follows the NRA Geographic Context for determining value set out in the Guidelines for Assessment of Ecological Impacts of National Road Schemes (NRA 2009b). In the context of national projects, ecological resources of below local importance (higher value) should not be selected as Key Ecological Receptors, for which detailed assessment is required.

The Tolka River has been determined to be of county importance, as there are records of Atlantic salmon in the river from 2011, although it is not designated as a salmonid river. The presence of a protected species in the watercourse indicates it is of a high ecological importance, albeit not at a national or international level.

The Santry River, Mayne River and Cuckoo Stream are evaluated to be of local importance (lower value), based on desktop and field survey findings. The rivers/stream contained limited areas of natural habitat and have limited biodiversity, with Q-values ranging from Q2 to Q3 (Bad to Poor ecological status). Following the criteria set out by the Guidelines for Assessment of Ecological Impacts of National Road Schemes (NRA 2009b), these ERs should not be selected as Key Ecological Receptors for which detailed assessment is required. However, given that these ERs act as pathways to downstream protected areas in the marine environment, and therefore the potential for indirect impacts exists, they are retained in the assessment to ensure full consideration of these potential impacts, and to allow for appropriate mitigation measures to be incorporated into the Proposed Project.

The downstream SACs and SPAs that are hydrologically connected to the Proposed Project works areas are considered to be of international importance.

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Table 11.20: Description of Habitats and Macroinvertebrate Communities at the Sampled Locations

Aquatic Habitat River Connectivity, Habitat Characteristics Potential Annex II Fishery Value Q-Rating Q-Rating Ecological Ecological Site Downstream Species/Supporting 2015 2017 Valuation Receptor Receptors Habitat ER1 Location 1 Tolka River Direct connectivity to  Shaded upstream of the M50 None observed. Fair spawning Q2-3. Not sampled County Not crossed by the North Dublin Bay Motorway bridge, limited habitat for Moderately in 2017 due Importance Proposed Project. SAC, South Dublin shading downstream. Good habitat for salmonids and polluted. to (upstream and Bay and River Tolka white-clawed lamprey. access downstream of the M50 Estuary SPA and  8m to 10m wide. crayfish. Abundant Poor difficulties Motorway at North Bull Island refugia and foraging Good nursery ecological at the time Abbotstown Bridge, SPA  The substrate consisted of potential. habitat for status. of survey. south of the proposed bedrock and boulder/cobble salmonids. Abbotstown pumping mix upstream with sand/silt River will not station). deposition downstream. Good habitat for be crossed by lamprey the Proposed  Water depth was 0.8m to 3m. ammocoetes Project. utilising marginal  In-stream vegetation consisted soft sediments. of bulrush and yellow iris downstream of the M50 Motorway and algae on the hard surfaces.

 Filamentous algal cover age: approx. 30%.

 Oil slick visible on downstream section.

 Excessive rubbish on riverbed on upstream section.

 Riverbanks are well-vegetated, forming a near-continuous riparian corridor comprising a dense mix of mainly grasses, nettle, giant rhubarb, willow, alder and thistle (see Plate 11.1 – Photos 1 and 2 below).

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Aquatic Habitat River Connectivity, Habitat Characteristics Potential Annex II Fishery Value Q-Rating Q-Rating Ecological Ecological Site Downstream Species/Supporting 2015 2017 Valuation Receptor Receptors Habitat ER2 Location 2 Santry River Direct connectivity to  Shaded section of stream None observed. Poor spawning Q2. Q2-3. Local (Accessed via pasture North Dublin Bay channel with a glide/riffle type habitat for salmon Seriously Moderately importance land west of Silloge SAC, South Dublin habitat and a substratum of Poor habitat for and lamprey. polluted. polluted. (lower Park Golf Club). Bay and River Tolka bedrock, sand and silt white-clawed value) Estuary SPA and deposition. crayfish due to low Poor nursery Bad Poor North Bull Island quality aquatic habitat for ecological ecological SPA  Water depth 0.2m to 0.6m. habitat and reduced salmonids and status. status. foraging potential. lamprey due to low  In-stream vegetation consisted flow channel and of rooted bulrush along central poor water quality. channel.

 Filamentous algae attached to hard substrates.

 Riverbanks are well-vegetated, forming a near-continuous riparian corridor comprising a dense mix of bramble, beech, willow, ivy, nettle, thistles, rumex, hazel, hogweed, cow parsley and grasses (see Plate 11.1 – Photos 3 and 4 below).

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Aquatic Habitat River Connectivity, Habitat Characteristics Potential Annex II Fishery Value Q-Rating Q-Rating Ecological Ecological Site Downstream Species/Supporting 2015 2017 Valuation Receptor Receptors Habitat ER3 Location 3 Mayne River Direct connectivity to  Slow-flow habitat over a None observed. Poor spawning for Q2. Q2. Local (Section accessed at Baldoyle Bay SAC compacted substratum salmon and Seriously Seriously importance Collinstown Business and Baldoyle SPA comprised of predominantly Poor habitat for lamprey. polluted. polluted. (lower Park east of Turnapin cobble and some coarse white-clawed crayfish value) Bridge). gravel with overlying silt. due to lack of Poor nursery Bad Bad overhanging banks, habitat for salmon ecological ecologic  Depth varies from 0.1m to poor invertebrate and lamprey due status. al 0.4m. assemblages and to low flow, status. degraded water channel and poor  No in-stream vegetation or quality. water quality. macrophyte beds present.

 Filamentous algal coverage was patchy with silty plumes observed after bed disturbance.

 Very steep banks either side of channel. (see Plate 11.1 – Photos 5 and 6 below).

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Aquatic Habitat River Connectivity, Habitat Characteristics Potential Annex II Fishery Value Q-Rating Q-Rating Ecological Ecological Site Downstream Species/Supporting 2015 2017 Valuation Receptor Receptors Habitat Location 5 Mayne River  Low flow pool dominated No otters observed. Poor spawning for Not Q2. Local (at proposed access section with only a small area salmon and sampled. Seriously importance road to proposed of riffle habitat. No prints or spraints lamprey New site polluted. (lower WwTP and Craobh recorded along bank. Established value) Chiaráin GAA grounds)  Bed comprised predominantly However, there is Poor nursery in 2017. of cobble with covering layer of potential for otter habitat for Bad silt. activity with some salmonids. Ecological cleaner sections of status.  Depth varies from 0.15m to 1m the river downstream Poor habitat for in parts. providing more Lamprey suitable for foraging Ammocoetes  Bramble and willow common sites. utilising marginal and riparian grasses present soft sediments. Poor habitat for white  No filamentous algal cover and clawed crayfish due large plumes of silt suspended to siltation of on disturbance. potential refugia.

 Horses accessing channel downstream.

 Highly shaded along the length of the habitat due to grassy verges and excessive bramble and fern growth.

 Butterfly bush present in the riparian zone.

 Some dumping.

 (see Plate 11.1 – Photos 9 and 10 below)

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Aquatic Habitat River Connectivity, Habitat Characteristics Potential Annex II Fishery Value Q-Rating Q-Rating Ecological Ecological Site Downstream Species/Supporting 2015 2017 Valuation Receptor Receptors Habitat ER4 Location 4 Cuckoo Stream Direct connectivity to  Moderate to fast flow with None observed. Poor spawning for Q3. Q2-3. Local (Mayne River Tributary) Baldoyle Bay SAC compacted substratum salmon and Moderately Moderately importance Intersecting arable field. and SPA comprised of predominantly Good habitat for lamprey polluted. polluted. (lower cobble and boulder. white clawed crayfish value) was observed as silty Poor nursery Poor Poor  Silt deposits line undercut marginal sections habitat for ecological ecological bankside edges. and undercut banks salmonids status. status. provide good habitat. Poor habitat for  Depth varies from 0.1m to Lamprey 0.8m. Ammocoetes utilising marginal  No in-stream vegetation or soft sediments. macrophyte beds present.

 Filamentous algal coverage was extensive on downstream channel and proliferated along extraneous material recorded on river bed.

 Upstream channel dominated either side by overhanging hazel and hawthorn trees lining bankside intertwined with excessive bramble (Rubus) growth (see Plate 11.1 – Photos 7 and 8 below).

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Photo 1: Tolka River at Abbotstown – Upstream Photo 2: Tolka River at Abbotstown – Downstream (Location 1) (Location 1)

Photo 3: Upstream of Santry River Tributary West of Photo 4: Downstream of Santry River Tributary West Silloge Park Golf Club (Location 2) of Silloge Park Golf Club (Location 2)

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Photo 5: Cobble/Gravel/Silt Mix Substratum at Mayne Photo 6: Steep Bank with Narrow Channel at Mayne River Tributary East of Turnapin Bridge (Location 3) River Tributary East of Turnapin Bridge (Location 3)

Photo 7: Downstream View of Narrow, Shaded Channel Photo 8: Upstream View of Cuckoo Stream (Location at Cuckoo Stream (Mayne River Tributary) (Location 4) 4)

Photo 9: Downstream of Mayne River Proposed Photo 10: Downstream of Mayne River Proposed Access Road to Proposed WwTP (Location 5) Facing Acess Road to Proposed WwTP (Location 5) Facing Upstream. Downstream.

Plate 11.1: Images of Sampled Watercourse Locations

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11.10 Impact of the Proposed Project on Freshwater Aquatic Biodiversity – Construction Phase In the absence of adequate mitigation, the Proposed Project has the potential for impacts on the watercourses within the ZoI of the Proposed Project, which includes the downstream marine sites which are hydrologically connected to the Proposed Project via river pathways. The potential impacts include contamination with deleterious substances generated during the Construction Phase, including the possible introduction of invasive species, and during the Operational Phase, runoff from hard surfaces at the proposed WwTP at Clonshagh and proposed Abbotstown pumping station. The primary discharge from the proposed WwTP will be to the marine environment, and therefore there will be no untreated wastewater discharged to freshwater ERs. The potential impact from the primary discharge has been assessed in Chapter 9 Biodiversity (Marine).

All watercourse crossings by the proposed orbital sewer route (total of three crossings) as shown in Figure 11.17 Freshwater Sampling Locations will be by trenchless techniques. The proposed construction corridor for the proposed outfall pipeline route (land based section) is 40m wide to allow for the movement of heavy plant and temporary storage of construction materials. The proposed construction corridor will be reduced to a proposed 20m wayleave to facilitate maintenance of the pipeline for its operational life. The use of trenchless techniques for the watercourse crossings will protect the watercourses from the potential significant impacts associated with traditional in-stream trench type methods or wet open cut methods. Trenchless techniques are commonly used to avoid impacts to environmentally sensitive areas such as SACs or SPAs, or to streams/rivers which are within the upstream catchment of an SAC or SPA as is the case for this Proposed Project. The specific method to be employed will be either pipe jacking or microtunnelling, to be confirmed at the detailed design stage when the ground conditions have been determined in greater detail (see Chapter 4 Description of the Proposed Project for further details). The potential impacts associated with trenchless crossing techniques are the same regardless of the specific method used.

The drilling methods will involve microtunnelling through the soil and passing the pipe through the tunnel behind a bore. The installation starts with a pilot hole being drilled along the predetermined drill path. Bentonite clay suspension or a polymer mix is used to reduce friction between the soil and the pipe. The pipe, once in place and prior to backfilling around the pipe, will be pressure tested using a hydrostatic/water test on the full length of pipeline to ensure there are no leaks. Each of the trenchless techniques follow similar steps and carry similar potential risks, e.g. bentonite blow out, risk of sedimentation generated at launch and reception pits and during pressure testing, which are described below. Trenchless watercourse crossings must consider a number of factors, including the width of the channel and topography of the river valley, suitable locations for entry and exit pits, disturbance associated with the pits, pipe bending radius, stresses associated with pulling the pipe through the drill bore, geotechnical conditions and restoration of conditions at the works areas post construction.

No in-stream works are proposed for any watercourse crossed by the proposed orbital sewer route or the proposed outfall pipeline route (land based section). In-stream works will be required where a proposed access road will be constructed from the R139 Road to the proposed WwTP, and this will require the installation of a culvert and widening of the bridge over the Mayne River, currently leading to Craobh Chiaráin GAA pitches (survey location 5, Figure 11.17 Freshwater Sampling Locations).

The Proposed Project onshore elements are spread from Blanchardstown to Portmarnock, and as a result, proposed construction access routes are widespread. Proposed construction access routes will be required for the delivery and removal of material, plant and personnel to the works locations. Works on public roads are limited to a number of crossing points, and the majority of these will be crossed by trenchless techniques. Other than at the new entrance to the proposed WwTP/Craobh Chiaráin GAA grounds, there will be no new roads constructed over watercourses to facilitate the Proposed Project. The potential for impacts associated with proposed access roads arise from the generation of dust, dirty machinery, spillage or leakage of fuels, oils or onboard materials.

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The potential significant impacts during the Construction Phase associated with these works are described below. General impacts associated with all elements of the works include sedimentation, pollution with other substances, introduction of invasive species, and the risk of incidences or accidents. Site specific impacts are associated with trenchless river/stream crossing works, installation and use of proposed temporary construction compounds during the Construction Phase, culvert system installation at survey location number 5, use of access roads and potential changes in hydrology as a result of the construction of hardstanding areas.

Suspended Solids Pollution The potential for pollution with suspended solids will be an issue within the Proposed Project at all locations where:

 Demolition works are undertaken;  The proposed temporary construction compounds will be temporarily established;  Construction site drainage takes place;  Permanent drainage features are constructed;  Permanent hard surfaces are constructed;  There are 19 proposed outfalls to ditches, road drainage and local watercourses (post-attenuation);  Earthworks (cut/fill) occurs. The Proposed Project has the potential to generate significant quantities of waste material, the primary sources being surplus excavated material associated with the proposed orbital sewer route construction, excess material from deep excavations required for the construction of the proposed Abbotstown pumping station, excess material from the construction of the proposed WwTP, and excess material from the construction of the proposed outfall pipeline route (marine section) and tunnel spoil. Surplus material in the order of 215,000m3 has been quantified, and  At river/stream crossing locations during trenchless works and culvert system construction (three river crossings and one access road crossing). Sediment-laden runoff from construction areas and introduction of fine sediments can pose adverse impacts to aquatic life in watercourses resulting in the following range of impacts:

 Reduction of visibility in the stream, impairing foraging ability for fish;  Settled sediments can smother and displace aquatic organisms, such as macroinvertebrates, reducing the amount of food items available to fish;  Suspended solids particles can clog or damage the gills of salmonid fish;  The settlement of suspended solids particles on spawning areas can smother the eggs in the gravel;  Higher concentrations of suspended solids may also serve as a sink or carrier for toxins/chemicals; and  Water with higher concentration of solids retards photosynthesis. In the absence of mitigation, suspended solids impacts would be expected to be moderately negative on a local scale, with short-term impacts during the Construction Phase for all AERs with the potential for sedimentation to be transported downstream to the marine environment. This is based on the reduced capacity of these streams to sustain further sedimentation, which would further reduce their water quality status. Each of the three rivers and the Cuckoo Stream are currently failing to meet their Good status objectives. Pollution with Other Substances

There is potential for a range of pollutants to enter watercourses during the construction of the Proposed Project at river crossings, activities at proposed temporary construction compounds and satellite offices/welfare facilities, and during the construction of the new culvert system at location 5. The following will have harmful impacts on fish, plants and invertebrates if allowed to enter the freshwater:

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 Raw or uncured concrete and grouts;  Excessive dust emissions from excavation and transportation of materials can potentially dissipate to nearby watercourses;  Wash down water from exposed aggregate surfaces, cast-in-place concrete and from concrete trucks; and  Fuels, lubricants and hydraulic fluids for equipment used for construction purposes. In the absence of mitigation, contaminated substances released to the environment during the Construction Phase would be expected to impact moderately negatively, on a local scale with medium-term impacts for all AERs and with the potential for these substances to indirectly affect the downstream marine environment. The assessment takes into account the toxic nature of the inputs, e.g. concrete, and the already reduced status within these watercourses which require significant protection in order to restore them to Good status.

Trenchless Crossings

Trenchless crossing methods will be employed at three crossing points: one on the Santry River, one on the Mayne River and one on the Cuckoo Stream (tributary of the Mayne River). The use of trenchless techniques for watercourse crossings is a mitigation measure in itself, and has been built into the design of the Proposed Project in order to avoid significant impacts to the freshwater and downstream marine environment. However, there remains the risk of some impacts associated with trenchless crossing works, which include:

 Large volumes of spoils will be removed from the tunnel under the watercourse. Spoil material, if improperly stored, can act as a source of sedimentation. Increased suspended solids can lead to increased deposition of fine sediment (silt/clay) onto the river bed. By altering the bed structure, excessive deposited sediment removes habitats for macroinvertebrates, reduces suitable substrate for fish spawning and impacts on the river’s morphological condition;  Interception of the hyporheic zone (zone of interaction between river and groundwater) or groundwater during trenchless crossing of streams may lead to large volumes of sediment-contaminated waters being produced, which would require treatment prior to discharge;  During trenchless crossing techniques, bentonite clay or other suitable material is pumped at pressure into the space between the pipe’s surface and the soil. There is potential for ‘blowout’, where bentonite escapes to the surface, potentially entering the watercourse. Release of bentonite to the watercourse would alter the substrate structure by coating habitats for macroinvertebrates, reducing suitable substrate for fish spawning and impairing in-stream water clarity; and  Noise and vibration impacts to the stream bed which may disturb fish in-stream is a potential risk. Anthropogenic noise and vibration impacts to freshwater fish is not a well understood area of science, although there is growing evidence that anthropogenic noise has an adverse effect on fish behaviour and physiology. In the absence of mitigation, impacts resulting from trenchless crossing techniques would be expected to be moderately negative on a local scale, with short-term impacts during the Construction Phase for AERs 2, 3 and 4 (Santry River, Mayne River and Cuckoo Stream).

Construction of Culvert System at Location 5

Installation of a new culvert system and proposed access road at location 5 is proposed. The primary impacts associated with these activities on aquatic receptors are:

 The potential for the obstruction of the passage of fish and aquatic fauna. The effect of a particular culvert on salmonids will depend on, e.g., water depth, speed and volume, length of culvert, type of culvert, species of fish, size and condition of fish. Physical alteration of stream channels can result in altered hydraulic characteristics and changes in stream profile, particularly in width, depth, gradient and current speed. Above a critical flow velocity, fish can only sustain progress for a limited period of time without resting. The faster the current velocity above this critical speed, the shorter the distance the fish can travel against the current. The impact of a culvert on fish movement is therefore primarily due to changes in

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hydrological conditions. Other factors such as the length of the structure and light are commonly used as significant criteria in determining the fish passage capability of an installation. The preference of IFI (2016) is the use of clear span bridge structures, followed by bottomless box culverts instead of box culverts or pipe culverts; and  Aquatic invertebrates may travel long distances within a stream by their own power in the case of snails, amphipods, crayfish and other crustaceans. As many of these species are confined to the water, any barrier to their dispersal impacts their populations. By eliminating the natural aquatic vegetation and its associated invertebrate fauna, culverts can result in a significant reduction in invertebrate drift downstream which constitutes a significant food source for salmonid fish. In the absence of mitigation, culvert impacts would be expected to be moderately negative on a local scale and permanent for AER 3 (Mayne River), given the existing physical alterations on the Mayne River, which are already leading to a barrier to fish migration, and the existing stream flow conditions. That said, IFIs comments which seek fish passible structures on the Mayne River are recognised. Construction of the Proposed Access Roads

Construction access will be required for delivery and removal of material, plant and personnel. Access routes for use as part of the Proposed Project primarily involve national primary and secondary existing routes, e.g. N2 National Road and N3 National Road, M50 Motorway and the R132 Swords Road, and short sections of regional roads. Three temporary proposed access roads are also required within the proposed construction corridor. The importation and disposal of construction related material will entail the transportation of materials from quarries and to licensed waste disposal facilities. There is potential for site traffic to carry soil or other material on the wheels of vehicles out onto public roads, and also for debris lost on the road network to enter watercourses which are crossed by these public roads. Dust emissions from loads of materials leaving site could also be a source of impact.

In the absence of mitigation, impacts would be expected to be slight negative, on a local scale and of short duration during the Construction Phase for all AERs. It is unlikely that there will be an impact to downstream marine receptors via freshwater pathways given the potential volumes of debris or dust that could be emitted.

Potential Changes to Hydrology as a Result of Hardstanding Areas

The pattern of runoff from hardstanding areas and the location of outfalls from these areas as a consequence of the installation of temporary drainage systems (to facilitate the Proposed Project works) to the freshwater environment can lead to localised scouring and increased flow rates during rainfall events, in particular during peak events. Contaminated runoff to the aquatic environment at outfall locations may lead to localised point source loading of relevant pollutants and suspended solids.

Increases in hard standing and new proposed access roads can alter surface water infiltration rates and flow paths. The creation of impermeable and permanent surfaces will alter drainage patterns in the immediate vicinity of the proposed WwTP and at the proposed Abbotstown pumping station site and may lead to localised surface water flow path preferences.

In the absence of mitigation, hydraulic impacts would be expected to be moderate negative on a local scale and permanent for AER 1 (Tolka River) as a consequence of the proposed Abbotstown pumping station and AER 4 (Cuckoo Stream) as a consequence of the proposed WwTP. Impacts are predicted to be slightly negative on a local scale for AER 3 (Mayne River) as a consequence of the new proposed access road to be built to the proposed WwTP. These impacts would be slightly negative on downstream marine receptors, and short-term in duration.

Proposed Temporary Construction Compound Areas Including Office and Welfare Facilities There is potential for site disturbance during the setup and utilisation of the proposed temporary construction compound areas to facilitate the works. Proposed temporary construction compound areas located close to

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watercourses have the potential to impact stream/river riparian corridors and alter surface water attenuation and flow paths. Activities such as vehicle movements and refuelling can all create the potential for spillages and leakages which may enter nearby watercourses.

The construction of proposed temporary construction compounds will require the removal of wastewater from toilets and domestic water from washing facilities which will require treatment and safe disposal to a suitable location. Inadequate treatment of on-site toilets and washing facilities has the potential to cause faecal contamination. In the absence of mitigation, impacts associated with the proposed temporary construction compound areas would be expected to be slightly negative on a local scale and short-term for all AERs and downstream marine receptors. Introduction or Transport of Invasive Species

The introduction and spread of invasive species, such as Japanese knotweed (Fallopia japonica), Himalayan balsam (Impatiens glandulifera), Giant hogweed (Heracleum mantegazzianum), on vehicles during the Construction Phase can have significant impacts on the ecological functioning of watercourses.

In the absence of mitigation, impacts from the introduction of invasive species would be expected to be significant negative on a local scale and long-term for all AERs and downstream marine protected areas. Environmental Incidents and Accidents

An environmental incident or accident during the Construction Phase, e.g. a large-scale spillage of a contaminant such as diesel or cement which could enter local streams or the marine environment, would have a negative impact on the aquatic environment.

In the absence of mitigation, impacts would be expected to be significant negative on a local scale and long- term for all ecological receptors and downstream protected areas. Spillages of contaminants, depending on their concentration and volume, could lead to a toxic reaction within the streams, with further impacts on an already degraded fisheries habitat, with consequences for the chemical status of the watercourse as per WFD environmental quality standards.

11.11 Impact of the Proposed Project on Freshwater Aquatic Biodiversity – Operational Phase The potential significant impacts due to the existence and operation of the Proposed Project include:

 Pollution of the Tolka River, Santry River or Mayne River systems from the leakage or spillage of untreated wastewater during the Operational Phase of the proposed WwTP and the proposed Abbotstown pumping station or from the proposed orbital sewer route would have significant negative short-term impacts at a local scale for all AERs and downstream marine protected areas, until the pollution is contained and the breach rectified;  Any changes in hydrology due to runoff from impermeable surfaces within the proposed WwTP and the proposed Abbotstown pumping station sites reflected in changes in maximum and minimum flows would have a slightly negative impact at a local scale on in-stream flora and fauna, and will be temporary (i.e. associated with high rainfall events) given the sizes of the areas involved relative to the sizes of the catchments within which they sit; and  Accidental spillage of fuels, oils, chemicals or other polluting substances would be expected to be slightly negative on a local scale and temporary, given that this risk is largely associated with the Construction Phase when vehicle activity will be greatest, rather than the Operational Phase of the Proposed Project, which will see lower activity associated with maintenance requirements.

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11.12 Summary of Potential Impacts in the Absence of Mitigation Measures Table 11.21 outlines the potential impacts from the Proposed Project in the absence of mitigation.

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Table 11.21: Impacts of the Proposed Project in the Absence of Mitigation

Potential Impacts During the Construction Phase Potential Impacts during the Operational Phase Aquatic Location and Suspended Pollution with Introduction of Trenchless Culvert and Construction of Compound Areas Hydrological Environmental Pollution from Pipe Pollution from Accidental Ecological Rating Solids Pollution Other Substances Invasive Species Crossing Bridge Access Roads Changes Incidents and Leakage/Spillage of Runoff from Spillage of Receptor Construction Accidents Untreated Wastewater Hardstanding Fuels/Oil/ Areas Chemicals

ER1 Tolka River Moderately Moderately negative Significantly negative No impact No impact Slightly negative on a Slightly negative on a Moderately Significantly Slightly negative on a local Slightly negative on Slightly (Location 1) negative on a on a local scale, on a local scale, long- local scale, short-term local scale, short-term negative on a negative on a local scale, temporary a local scale, negative on a of county local scale, short- medium-term term local scale, scale, long-term temporary local scale, importance term permanent temporary

ER2 Santry River Moderately Moderately negative Significantly negative Moderately No impact Slightly negative on a Slightly negative on a No impact Significantly Slightly negative on a local No impact Slightly (Location 2) negative on a on a local scale, on a local scale, long- negative on a local local scale, short-term local scale, short-term negative on a local scale, temporary negative on a of local local scale, short- medium-term term scale, short-term scale, long-term local scale, importance term temporary (lower value) ER3 Mayne River Moderately Moderately negative Significantly negative Moderately No impact Slightly negative on a Slightly negative on a No impact Significantly Slightly negative on a local Slightly negative on Slightly (Location 3) negative on a on a local scale, on a local scale, long- negative on a local local scale, short-term local scale, short-term negative on a local scale, temporary a local scale, negative on a of local local scale, short- medium-term term scale, short-term scale, long-term temporary local scale, importance term temporary (lower value) Mayne River Moderately Moderately negative Significantly negative No impact. Moderately Slightly negative on a No impact Slightly negative Significantly No impact Slightly negative on No impact (Location 5) negative on a on a local scale, on a local scale, long- negative on a local scale, short-term on a local scale, negative on a local a local scale, of local local scale, short- medium-term term local scale, permanent scale, long-term temporary importance term permanent (lower value) ER4 Cuckoo Stream Moderately Moderately negative Significantly negative Moderately No impact Slightly negative on a Slightly negative on a Moderately Significantly Slightly negative on a local Slightly negative on Slightly (Location 4) negative on a on a local scale, impact on a local negative on a local local scale, short-term local scale, short-term negative on a negative on a local scale, temporary a local scale, negative on a of local local scale, short- medium-term scale, long-term scale, short-term local scale, scale, long-term temporary local scale, importance term permanent temporary (lower value)

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11.13 ‘Do Nothing’ Impact on Freshwater Aquatic Biodiversity If the Proposed Project does not proceed, ongoing activities would continue within the Proposed Project boundary which may include further urbanisation, airport activities and intensive agriculture. These activities would be likely to result in localised and moderate scale impacts to the AERs within the ZoI, with resulting indirect impacts to the downstream marine environment. This would result in the freshwater biodiversity along the Proposed Project route potentially remaining as it is at present or potentially being impacted further in terms of its ecological status classification. Environmental objectives under the Draft River Basin Management Plan for Ireland 2018–2021 (DoHLG 2017) have not yet been established for these waterbodies; however, Good status is the minimum environmental objective set under WFD, with varying timelines for the achievement of that objective.

11.14 Mitigation Measures – Freshwater Aquatic Biodiversity This Section prescribes best practice measures to be employed throughout the works area, and where required, site specific mitigation measures that will be implemented to avoid, reduce or remedy potential impacts identified above in Section 11.10 and Section 11.11.

11.14.1 Construction Phase An ECoW will be appointed by Irish Water or its agents to monitor and regularly inspect the implementation of all ecological mitigation contained in this EIAR, associated NIS and the Outline CEMP, and to act as a liaison between Irish Water and ABP in the discharge of planning conditions relating to biodiversity.

A detailed CEMP will be developed by the appointed contractor(s). An Outline CEMP and Outline Surface Water Management Plan have been developed and are included as part of the Planning Documentation for the Proposed project. This includes the best practice measures outlined in this Chapter, and site specific mitigation measures, where identified. All site operatives shall be fully informed in advance of any works of the ecological sensitivities in the surrounding environment, and the required mitigation measures will be in place in advance of works.

Suspended Solid Pollution The reduction and prevention of suspended solid pollution will be required during all elements of the Proposed Project works, including:

 During site preparation and clearance works (cut/fill operations);  Where trenchless operations are undertaken;  Where the culvert system at location 5 is constructed along with the new proposed access road to the proposed WwTP;  Where site proposed access roads are constructed;  Where the proposed WwTP and Abbotstown pumping station construction works are undertaken, and  Where proposed temporary construction compounds are temporarily installed. As such, this Section outlines best practice mitigation measures for the control of suspended solid pollution to the freshwater environment, and site-specific measures, where required. The key factors in erosion and sediment control are to intercept and manage runoff. This limits the potential for soils to be eroded and enter streams in runoff and traveling downstream to marine protected areas. Best practice measures to be implemented are:

 The appointed contractor(s) will develop the Outline Surface Water Management Plan and Sediment Control Plan, which will form part of the CEMP, in advance of any construction activities commencing for

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the Proposed Project (the principles of which are detailed in the Outline CEMP). The Surface Water Management Plan will adopt mitigation proposed in Chapter 17 Hydrology and Hydrogeology of this EIAR;  All discharges to surface waters will be suitably treated prior to discharge. There will be no direct discharge of surface water from any element of the works without proper attenuation and treatment. The level of suspended solids in any discharges to fisheries waters, e.g. the Tolka River (or waters with fisheries potential e.g. the Santry River, Mayne River and Cuckoo Stream), as a consequence of construction works shall not exceed 25mg/l8 nor result in the deposition of silts on gravels or any element of aquatic flora and fauna as per IFI guidelines (IFI 2016). If baseline suspended solid levels in pre-construction monitoring show that these rivers exceed this threshold, the baseline suspended solid levels will not exceed baseline levels during the Construction Phase of the Proposed Project;  Pathways of preferential flow are identified within the works area in the Outline Surface Water Management Plan, and the appropriate mitigation measures will be undertaken by the appointed contractor(s), as presented, to ensure contaminated water from the site is treated before being discharged to the watercourse. Pathways of preferential flow on a small scale are determined by the topography of the site and are subject to change as works are undertaken, and therefore will need to be determined on-site by the appointed contractor(s), and agreed with the ECoW. All vulnerable infrastructure, e.g. the proposed WwTP and Abbotstown pumping station, are to be located in Flood Zone C – low risk. Similarly, all proposed temporary construction compounds, storage areas and launch pits (for trenchless technologies) will be located, where possible, within Flood Zone C – low risk. The following best practice guidelines for erosion and sediment control will be adhered to during the Construction Phase, and will inform appropriate mitigation. These guidelines are largely based on publications by CIRIA (Murnane et al. 2006), Goldman et al. (1986), Murphy (2004) and IFI (2016): o Sediment traps or settlement ponds shall be provided for all works near watercourses during construction in order to attenuate and treat all water prior to discharge, and will adhere to the IFI guidelines (IFI 2016); o Works within and adjacent to watercourses will only be conducted during forecast low flow periods; o The design of the outfalls and settlement ponds and the construction method statements for their installation shall be agreed with IFI prior to construction; o Topsoil stripping near to any watercourses will be undertaken in dry weather conditions, and all stockpiles will be located further than 100m from a watercourse or removed off site. Stockpiles within 200m of a watercourse will be covered; o Stripped areas will be revegetated, particularly cut and fill slopes and disturbed slopes, as soon as possible (for example by use of hydroseeding (larger areas) and replacement of turves (smaller areas)). Mulches or other organic stabilisers will be used to minimise erosion until vegetation is established on sensitive soils. Hydroseeding shall not be carried out in close proximity to water, and these areas will be seeded by hand or placement turves used; o Runoff velocities and erosive energy will be minimised by maximising the lengths of flow paths for precipitation runoff, constructing interceptor ditches and transport, and lining unavoidably steep interceptors or conveyance channels with low gradients to minimise secondary erosion and ditches with filter fabric, rock or polyethylene lining to prevent channel erosion; o The crossing of watercourses at natural fords will not be permitted due to the uncontrolled sedimentation that can be generated; o The creation of fords on streams and rivers through the introduction of stone shall be prohibited; o There will be designation of appropriate locations set back from watercourses and methods for stockpiling, for example, soil, aggregates and chemicals; o Heavy vehicle movements will be restricted adjacent to watercourses and tidal areas in order to avoid inputs;

8 The standard is expressed as an average concentration over a period of 12 months and does not apply to suspended solids with harmful chemical properties. European Communities (Quality of Salmonid Waters) Regulations 1988 (S.I. No. 293 of 1988).

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o Runoff from stockpiles will be collected via a shallow toe-drain which will discharge to a settlement pond. Settlement ponds will be designed and sized to adequately attenuate suspended solid runoff from stockpile areas. Sediment build-up will be removed at regular intervals by manual means only and will be treated at an appropriately authorised waste management facility; o Existing and proposed surface water drainage and discharge points shall be mapped on a site plan including the location of existing and proposed measures such as monitoring points, sediment traps, settlement lagoons and hydrocarbon separators; o Site access roads shall be constructed of a non-friable, clean, well-graded material, typically of NRA Clause 804, to ensure the material does not break down under loading; o No water that has gathered on-site from any source (groundwater, surface water or precipitation) will be pumped directly to the surface water drainage network. All water intercepted on-site must be attenuated in sediment control structures for sufficient time to ensure that sediment concentrations are appropriate before discharge; o No in-stream structures, strictly no temporary stream crossings or temporary culverting shall take place without the prior agreement of IFI; and o Excavations for foundations will be carried out so as to minimise sediment runoff. Chapter 17 Hydrology and Hydrogeology provides further specification for suspended solid control.

Site specific measures to be implemented are as follows:

 The northern boundary of the proposed WwTP site is set back from the Cuckoo Stream. Earth mounds and planting will occur within 50m of the stream. However, these works will not take place within 20m of the stream, as riparian vegetation plays a crucial role in removing sediment in over-land flows. Riparian vegetation is a vital component of a healthy stream ecosystem and will be preserved. The site will be stripped and earth mounds will be formed as work progresses along the site boundary. These mounds/planting will provide a buffer to further protect the Cuckoo Stream in conjunction with the maintained 20m riparian buffer. Earth mounds will be revegetated as soon as possible, e.g. by use of hydroseeding (for larger areas). Broadleaves will be planted in this area adjacent to the Cuckoo Stream to encourage a mixture of dapple and shade conditions benefiting in-stream flora and fauna;  Where trenchless crossing works take place, i.e. within 200m of the Tolka River and crossing under the Santry River, Mayne River and Cuckoo Stream, a riparian buffer strip at least 20m in width (from the edge of the watercourse on either bank) shall be clearly marked and maintained, to protect the watercourse from any potential impact. Reception and launch pits from trenchless operations will not be located within this 20m buffer. Silt fencing will be installed along the 20m buffer line to isolate the works area from the relevant watercourses. A detailed Pollution Control Plan, Emergency Response Plan and Method Statements will be drafted in agreement with IFI and other relevant authorities;  Suspended solid pollution associated with culvert system installation will be avoided by use of a clear span structure if possible or, where a bottomless box culvert is installed, will follow IFI guidelines (IFI 2016) for works in or adjacent to watercourses. Mitigation will include protection of the riparian bank structure, minimisation of sedimentation to the watercourse by use of silt fencing, sand bags or other sediment reducing measures, and minimisation of in-stream activity; and  The appointed contractor(s) will inspect and monitor the water quality of surface waters near any works, paying particular attention to suspended solids and turbidity levels. This monitoring will form part of the CEMP for the works. Trenchless Crossing of Watercourses

The primary mitigation measure for the protection of the freshwater environment during the Construction Phase of the Proposed Project is the use of trenchless techniques to cross the watercourses. This approach will protect the streams and downstream marine protected areas from the significant impacts of traditional trench based methods. Nevertheless, there are some risks associated with the various trenchless methods, and mitigation for these is outlined below:

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 Reception and launch pits for the directional drilling process shall not be located within 20m of any watercourse;  Direct disposal of arisings from excavations and from groundwater dewatering activities to the nearby watercourses will not be allowed. Any discharge of such water, after proper treating/de-silting, will be discussed and agreed with the landowner, and if necessary, discharge consent will be acquired from the concerned authority (EPA, IFI) prior to the commencement of work;  If drilling fluids are being returned for cleaning and reuse or recirculation through a temporary fluid return line, pneumatic leak testing shall be carried out to confirm the integrity of the return line;  Spent drilling fluids including separated drill materials shall be contained in secure bunded areas within selected proposed temporary construction compounds for off-site disposal at a licensed disposal facility;  To avoid reception and launch pits being open for longer than is necessary, all ducting required shall be available on-site prior to commencement of pit excavation;  Marker posts will be placed at each side of the streams/rivers identifying the location of the crossing;  Stream crossing works, including preparatory works, shall be carried out under the supervision of a suitably qualified ECoW;  Upon completion of works at each stream crossing, the site shall be cleaned and any waste disposed of to a suitably licensed facility;  Pipes, once in place, will be hydrostatic/water tested to design capacity to validate pipe integrity; and  The appointed contractor(s) will inspect and monitor the water quality of surface waters near trenchless works, paying particular attention to signs of blowout and silt plumes. In the event of a bentonite break-out, then the site will be monitored for chemicals and macroinvertebrates to ensure no residual impacts following clean-up operations. This monitoring will form part of the CEMP for the works. Construction of Culvert System There is one culvert system proposed as part of the Proposed Project. This culvert system will be located on the proposed access road to the proposed WwTP at Clonshagh, and will cross the Mayne River at survey location number 5. The following mitigation has been included within the design of the Proposed Project, which is in line with the IFI’s Guidelines on Protection of Fisheries During Construction Works in and Adjacent to Waters (IFI 2016), in particular Section 6 (River and Stream Permanent Crossing Structures). During the Construction Phase, the appointed contractor(s) shall ensure that:

 In-stream works shall be undertaken during the period 1 July to 30 September, as required by IFI guidelines (IFI 2016), to avoid accidental damage or siltation of spawning beds, unless otherwise specified by IFI during consultations in advance of works. This shall include preparatory work near all watercourses and all river bank works;  Bank protection works will be required (e.g. upstream and downstream of the new structure) to ensure no undercutting or destabilisation of either the structure or riparian bank areas occurs. Rock armour will be installed and will include large enough boulders, strategically positioned to ensure they cannot be undercut; and  Bridge and culvert design has avoided impacting on flow regimes and river bed profiles upstream and downstream of the structure and has allowed for unimpeded movement of fish by ensuring a minimum depth of water within the structure. The river substrate will be maintained. The design will ensure that the flow regime for this crossing, which has the potential to support salmonids in the future, shall allow for the unimpeded passage of fish upstream and downstream by having the invert buried 500m below bed level. Due to the width of the river, and to prevent the foundations of these structures encroaching on the river, a precast box culvert will be installed at this location.

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Pollution with Other Substances Where the construction works are close to a watercourse, and at all watercourse crossings, the following best practice guidelines, adapted from Chilibeck et al. (1992), NRA (2005b) and Murphy (2004), shall be followed:

 Fuels, lubricants and hydraulic fluids for equipment used on the construction site should be carefully handled to avoid spillage, properly secured against unauthorised access or vandalism, and provided with spill containment according to Best Practice Guidelines BPGCS005 – Oil Storage Guidelines (Enterprise Ireland);  Best Practice Guidelines BPGCS005 – Oil Storage Guidelines (Enterprise Ireland);  Fuelling and lubrication of equipment shall not be carried out on-site within 20m of any watercourse or drainage ditch;  Any spillage of fuels, lubricants or hydraulic oils shall be immediately contained and a pollution control kit used. The contaminated soil shall be removed from the site and properly disposed of;  In the event of any spillage of fuels, lubricants or hydraulic oils, the ECoW will be notified immediately;  Oil booms and oil soakage pads shall be kept on-site to deal with any accidental spillage, and replenished immediately once used;  Waste oils and hydraulic fluids shall be collected in leak-proof containers and removed from the site for disposal or recycling;  All pumps using fuel or containing oil shall be locally and securely bunded and shall not be located within 20m of a watercourse or drainage ditch; and  Prior to any in-stream works, the appointed contractor(s) will ensure that all construction equipment is mechanically sound to avoid leaks of oil, fuel, hydraulic fluids and grease. Use of Concrete Concrete will be required as part of works undertaken to construct the proposed WwTP at Clonshagh, to construct the proposed Abbotstown pumping station and at manholes (at bends, changes in gradient and at specific locations along the proposed pipeline routes) and chambers. Mitigation in the form of avoidance of the use of concrete has been built into the design of the Proposed Project for the culvert discussed above, with a precast box culvert utilised. It is possible that the chosen pipe material may be concrete; however, the suitability of the particular materials will be considered further at the detailed design stage. Therefore, mitigation proposed here, includes for the scenario in which the pipe material is concrete.

The use and management of concrete, which has a deleterious effect on water chemistry and aquatic habitats and species, in or close to watercourses shall be carefully controlled to avoid spillage. Where the use of concrete near water cannot be avoided, the following control measures will be employed:

 When working in or near the surface water and the application of in situ materials cannot be avoided, alternative materials such as biodegradable shutter oils shall be used;  Any plant operating close to the water will require special consideration of the transport of concrete from the point of discharge from the mixer to final discharge into the delivery pipe. Care will be exercised when slewing concrete skips or mobile concrete pumps over or near surface waters;  Placing of concrete near watercourses will be carried out only under the supervision of the ECoW;  There will be no hosing of concrete, cement, grout or similar material spills into surface water drains. Such spills shall be contained immediately and runoff prevented from entering the watercourse;  Concrete waste and wash-down water will be contained and managed at Clonshagh and Abbotstown, where concrete works are proposed, and sediment allowed to settle out and reach pH neutral, before clarified water is discharged back to a watercourse or removed off-site;

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 On-site concrete batching and mixing activities will not be allowed and will be specifically prohibited in the contract documents;  Washout from concrete lorries, with the exception of the chute, will not be permitted on-site and will only take place at the batching plant (or other appropriate facility designated by the manufacturer);  Chute washout will be carried out at designated locations only. These locations will be signposted. The concrete plant and all delivery drivers will be informed of their location with the order information and on arrival on-site;  Chute washout locations will be provided with appropriate designated, contained impermeable area and treatment facilities including adequately sized settlement tanks, and  The clear water from the settlement tanks shall be pH corrected prior to discharge (which shall be by means of one of the Construction Phase settlement facilities) or alternatively disposed of as waste to a licensed facility. Surface Water Management along the Route Surface water management measures will be installed along the proposed pipeline routes in order to manage runoff through the wayleave in which construction is occurring. There will be shallow toe-drains located along the edges of the wayleave in order to catch runoff from the stockpiles of topsoils and subsoils resulting from the digging of the trenches for the pipeline. These toe-drains will drain into temporary settlement ponds which will be located along the proposed pipeline routes at regular intervals as required as construction progresses, and shall be sized based on calculations of hourly runoff volumes based on a 1 in 10 year rainfall event. These settlement ponds will collect surface waters flowing over the wayleave and into the toe-drains. The routes will be split into 19 separate sections for the purposes of surface water management. The Surface Water Management Plan provides details of the volumes of attenuation to be provided at each section along the proposed route, as well as outfall information. Sediment will be removed from the surface water prior to discharge through measures as per the guidance on control of water pollution from construction projects (CIRIA 2001) (for example silt screens or hay bales). The treated surface water will be discharged to local watercourses, ditches or road drainage as deemed suitable at locations along the pipeline route. There will be no direct discharge of surface waters from the site without prior attenuation and treatment. During pipeline construction, trenches shall not be left open overnight or for extended periods of time. Trenches shall only be dug to lengths which can be constructed each day. All trenches will be backfilled once the section of pipe is installed. This will prevent pooling of surface waters within open trenches. Proposed Temporary Construction Compound Areas Including Office and Welfare Facilities There will be a number of proposed temporary construction compounds (including those at the proposed WwTP and Abbotstown pumping station sites) as part of the Proposed Project. The following mitigation will apply together with suspended solids pollution measures outlined above:

 Sites for storage areas, machinery depots, site offices, construction of temporary access roads or the disposal of spoil will be located at least 50m from any watercourse;  All materials will be stored in compounds and shall be stored in a manner that is safe and in line with best industry practice. Fuels and chemicals will be stored in an appropriately bunded area/with double skinned tanks. All potential harmful substances will be stored in accordance with the manufacturer’s guidelines;  All aspects of the works will be watertight, which will include the pipelines, tanks, storage containers and pump sumps;  Wheel washing facilities will be installed at the entrance to the proposed WwTP site and other locations deemed appropriate;  Invasive species biosecurity measures will be installed at the entrance to the proposed WwTP site, proposed Abbotstown pumping station site and all proposed temporary construction compounds. This will adhere to the Biosecurity Protocol for Field Survey Work (IFI 2010); and

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 Foul drainage from compounds will be disposed of through the provision of a direct connection to a local sewer or be serviced by means of a waste water storage tank, which will be emptied by means of a suction tanker and the wastewater shall be disposed of to a licenced facility. Invasive Species No invasive species were found during freshwater surveys within the proposed pipeline routes. However, invasive species records are known from the wider catchments of the Tolka River and Santry River. There may be a risk associated with the spread of, or introduction of, invasive species via soil or other materials which will be imported to the site during construction work, or via machinery or equipment. The following mitigation shall be adhered to:

 All plant and equipment employed on the proposed construction corridor (e.g. excavator, footwear) will be thoroughly cleaned using a power washer unit prior to arrival on-site, and prior to leaving site, to prevent the spread of invasive aquatic/riparian species such as Japanese knotweed in accordance with the Office of Public Works’ (2011) Environmental Standard Operating Procedures and the IFI’s (2010) Biosecurity Protocols for Field Survey Work. A sign-off sheet must be maintained to confirm cleaning;  Staff involved in the works shall be informed as to the presence of invasive species in the area downstream along the Tolka River and Santry River. All staff working on the Proposed Project shall be familiar with the sections within the document Guidelines on the Management of Noxious Weeds and Non-Native Plant Species on National Roads (NRA 2008) which detail the treatment necessary for each of the aforementioned species, together with the required reporting procedure if encountered. All site staff will also be familiar with Information and Guidance Document on Japanese Knotweed Asset Strategy and Sustainability (Irish Water 2012); and  If invasive species are found within the works area during the course of construction works, a buffer zone will be marked around the invasive species, and plant and equipment that could transport the species within the site will be excluded. This will be reported to the ECoW, who will develop a plan of action in association with the appointed contractor(s). The significance of the buffer will be explained to machinery operators. Environmental Incidents and Accidents

 An emergency operating plan shall be established to deal with incidents or accidents during construction that may give rise to pollution within any watercourse. This shall include means of containment in the event of accidental spillage of hydrocarbons or other pollutants (including, for example, oil booms and soakage pads);  Throughout all stages of the Construction Phase of the Proposed Project, the appointed contractor(s) shall ensure that good housekeeping is maintained at all times and that all site personnel are made aware of the importance of the freshwater environments and the requirement to avoid pollution of all types;  All hazardous materials on-site will be stored within secondary containment designed to retain at least 110% of the storage contents;  Temporary bunds for oil/diesel storage tanks will be used on the site during the Construction Phase of the Proposed Project, as appropriate;  Safe handling of all potentially hazardous materials will be emphasised to all construction personnel employed during the Construction Phase of the Proposed Project, and an Emergency Response Plan shall be in place in case of accidental spillage;  Raw or uncured waste concrete will be disposed of by removal from the site;  Any spillage of fuels, lubricants or hydraulic oils will be immediately contained and the contaminated soil removed from the site and properly disposed of; and  There shall be no discharge of un-attenuated water to the adjacent marine environment.

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11.14.2 Operational Phase  The primary discharge from the proposed WwTP at Clonshagh will be to the marine environment, and mitigation for associated impacts are presented in Chapter 9 Biodiversity (Marine);  To mitigate against the potential for pipe failure or leakage during the Operational Phase, the proposed orbital sewer route design and construction will be to best practice requirements, as outlined in Chapter 4 Description of the Proposed Project. This includes the reduction in the number of pipe joints, which mitigates the potential for operational leakage. All pipelines will be subject to watertightness testing prior to sewage being passed through them. Flow monitors will be installed on the rising main leaving the proposed Abbotstown pumping station and on the inlet to the proposed WwTP. These will identify possible pipe bursts or significant leaks on rising mains, as this leads to a pressure drop off in the main which is monitored;  A Sustainable Drainage System shall be installed at the proposed WwTP site and the proposed Abbotstown pumping station site to manage water from hard surfaces from entering surface waters un-attenuated and untreated. Attenuation systems will be in place to limit discharges from the site to the greenfield site flow rate. The purpose of the Sustainable Drainage System will be to prevent sediment, grit and hydrocarbons from entering watercourses. Hydrocarbon and grit interceptors shall be located at outfalls to watercourses from hard standing areas of the proposed WwTP. Design of those interceptors shall conform to the recommendations of Control of pollution from highway drainage discharges (R142) (Luker and Montague 1994);  Surface water from the WwTP will be discharged to the Cuckoo Stream after attenuation and treatment. Treatment will include interceptors and attenuation tanks before discharge to the Cuckoo Stream. Surface water from the proposed WwTP’s roof will be collected in grey-water tanks. It will then either be recycled on the site, or discharged into the surface water drainage downstream of the fuel interceptors;  Interceptors will require proper maintenance in order to function properly. Irish Water shall adopt a program of regular cleaning, maintenance and inspection of the Sustainable Drainage System and associated interceptors to ensure they are functioning correctly; and  The proposed WwTP and the proposed Abbotstown pumping station will be designed with secondary containment to ensure that, in the unlikely event of leakage, the untreated wastewater is fully contained on- site.

11.15 Residual Impacts – Freshwater Aquatic Biodiversity An assessment of residual impacts identifies the impacts associated with the Proposed Project and the likely significance of impacts on the environment and its ecological features after the implementation of mitigation measures. With the successful implementation of mitigation measures outlined within Section 11.14, no significant residual impacts on freshwater biodiversity or downstream marine protected areas are predicted (see Table 11.22).

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Table 11.22: Summary of Residual Impacts During the Construction and Operational Phases

Residual Impacts from the Construction Phase Residual Impacts from the Operational Phase Aquatic Location Suspended Pollution with Introduction of Trenchless Culvert and Access Compound Hydrological Environmental Pollution from Pipe Pollution from Runoff Accidental Spillage of Ecological and Rating Solids Other Invasive Species Crossing Bridge Roads Areas Changes Incidents and Leakage/Spillage of from Hardstanding Fuels/Oil/Chemicals Receptor Pollution Substances Construction Accidents Untreated Wastewater Areas ER1 Tolka River Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant (Location 1) of county importance ER2 Santry River Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant (Location 2) of local importance (lower value) ER3 Mayne River Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant (Location 3) of local importance (lower value) Mayne River Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant (Location 5) of local importance (lower value) ER4 Cuckoo Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant Not significant Stream (Location 4) of local importance (lower value)

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11.16 References Baglinière, J. L., and Champigneulle, A. (1986). Population estimates of juvenile Atlantic salmon, Salmo salar, as indices of smolt production in the R. Scorff, Brittany. Journal of Fish Biology, 29(4): 467–482.

Bailey, M. and Rochford J. (2006). Otter Survey of Ireland 2004/2005. Irish Wildlife Manuals, No. 23. National Parks and Wildlife Service, Department of Environment, Heritage and Local Government, Dublin, Ireland.

Biodiversity Ireland (2017). www.biodiversityireland.ie (accessed July 2017).

Bjornn, T. C., and Reiser, D. W. (1991). Habitat requirements of salmonids in streams. American Fisheries Society Special Publication, 19(837): 138.

British Standards Institution (2012). BS 5837:2012 Trees in relation to design, demolition and construction.

British Standards Institution (2013). BS 42020:2013 Biodiversity: Code of practice for planning and development.

Chilibeck, B., Chislett, G., and Norris, G. (1992). Land Development Guidelines for the Protection of Aquatic Habitat.

Chartered Institute of Ecology and Environmental Management (2016). Guidelines for Ecological Impact Assessment in the UK and Ireland: Terrestrial, Freshwater and Coastal. Second Edition. Chartered Institute of Ecology and Environmental Management.

Department of Housing, Planning and Local Government. 2018. Draft River Basin Management Plan for Ireland 2018–2021.

Enterprise Ireland. Best Practice Guide (BPGCS005): Oil storage guidelines.

Environmental Protection Agency (2017). www.epa.ie and www.catchments.ie (accessed September 2017)

Environmental Protection Agency (2017). Draft Guidelines on the Information to be Contained in Environmental Impact Assessment Reports.

Fingal County Council (2010). Fingal Biodiversity Action Plan 2010-2015.

Fingal County Council (2017). Fingal Development Plan 2017-2023.

Goldman, S.J., Jackson, K. and Bursztynsky, T.A. (1986). Erosion and Sediment Control Handbook. McGraw-Hill.

Haury, J., Bagliniére, J. L., Cassou, A. I. and Maisse, G. (1995). Analysis of spatial and semporal organization in a salmonid brook in relation to physical factors and macrophytic vegetation. Hydrobiologia, 300(1): 269–277.

Heggenes, J. (1990). Habitat utilization and preferences in juvenile Atlantic salmon (Salmo salar) in streams. River Research and Applications, 5(4): 341–354.

Hendry, K. and Cragg-Hine, D. (1997). Restoration of Riverine Salmon Habitats: A Guidance Manual. Fisheries Technical Manual 4. Environment Agency.

Holdich, D. (2003). Ecology of the White-clawed Crayfish. Conserving Natura 2000 Rivers – Ecology Series No. 1. English Nature.

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Inland Fisheries Ireland (2010). Biosecurity Protocol for Field Survey Work.

Inland Fisheries Ireland (2011). A “New” Salmon River in Ireland [Online] Available from: http://www.fisheriesireland.ie/Press-releases/a-new-salmon-river-in-ireland.html [Accessed 24/05/2018].

Inland Fisheries Ireland (2016). Guidelines on Protection of Fisheries During Construction Works in and Adjacent to Waters.

Inland Fisheries Ireland (2017). Fishing in Ireland – An angler’s guide to fishing in Ireland [Online] Available from: www.fishinginireland.info [Accessed 24/05/2018].

Inland Fisheries Ireland (2018). IFI WFD Fish Data [Online] Available from: www.wdfish.ie [Accessed 2018].

Invasive Species Ireland (2017). Invasive Species Ireland [Online] Available from: www.invasivespeciesireland.com [Accessed 24/05/2018].

Irish Water (2012). Information and Guidance Document on Japanese Knotweed Asset Strategy and Sustainability.

Luker, M. and Montague, K. (1994). Control of pollution from highway drainage discharges (R142). CIRIA.

Maitland P.S. (2003). Ecology of the River, Brook and Sea Lamprey. Conserving Natura 2000 Rivers – Ecology Series No. 5. English Nature.

Meehan, S.T. (2013). IWT National Smooth Newt Survey 2013 Report.

Mills, D. (1989). Ecology and Management of Atlantic Salmon. Springer Science & Business Media.

Murnane, E., Heap, A. and Swain, A. (2006). Control of water pollution from linear construction projects. Technical guidance (C648D). CIRIA.

National Roads Authority (2005): Guidelines for the Treatments of Bats Prior to the Construction of National Road Schemes. National Roads Authority (2005a) Best Practice Guidelines for the Conservation of Bats in the Planning of National Road Schemes.

National Roads Authority (2005b). Guidelines for the Crossing of Watercourses During the Construction of National Road Schemes.

National Roads Authority (2008). Guidelines on the Management of Noxious Weeds and Non-Native Invasive Plant Species on National Roads. Revision 1.

National Roads Authority (2009a). Ecological Surveying Techniques for Protected Flora and Fauna during the Planning of National Road Schemes.

National Roads Authority (2009b). Guidelines for Assessment of Ecological Impacts of National Roads Schemes. Revision 2.

National Biodiversity Data Centre (2017). [Online] Available from: www.biodiversityireland.ie [Accessed September 2017].

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National Parks and Wildlife Service (2015). [Online] Available from www.npws.ie [Accessed November 2015].

National Parks and Wildlife Service (2017). [Online] Available from www.npws.ie [Accessed September 2017].

Northern Ireland Environment Agency (2014) Newt Surveys – NIEA Specific Requirements.

Office of Public Works (2011). The Office of Public Works Arterial Drainage Maintenance Environmental Management Protocols & Standard Operating Procedures.

Peay, S. (2003). Monitoring the White-clawed Crayfish. Conserving Natura 2000 Rivers – Monitoring Series No. 1.

Preston, C.D. and Croft, J.M. (2001). Aquatic plants in Britain and Ireland. Brill.

South Dublin County Council (SDCC). (2016). Development Plan 2016-2022 (Liffey Valley Special Amenity Areas Order 1990.

Symons, P.E.K. and Heland, M. (1978). Stream habitats and behavioural interactions of underyearling and yearling Atlantic salmon (Salmo salar). Journal of the Fisheries Board of Canada, 35(2): 175–183.

Toner, P., Bowman, J., Clabby, K., Lucey, J., McGarrigle, M., Concannon, C., Clenaghan, C., Cunningham, P., Delaney, J., O’Boyle, S., MacCárthaigh, M., Craig, M. and Quinn R. (2005). Water Quality in Ireland 2001-2003. Environmental Protection Agency.

WFD (2018). WFD Ireland Water Maps [Online] Available from: www.wfdireland.ie [Accessed 2018].

Directives and Legislation

European Communities (Birds and Natural Habitats) Regulations 2011 – S.I. No. 477 of 2011

European Communities (Quality of Salmonid Waters) Regulations 1988 – S.I. No. 293 of 1988

European Communities Environmental Objectives (Surface Waters) Regulations 2009 – S.I. No 272 of 2009

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