POC Maintenance Dredging Application | January 2014
Attachment F.1 Impact on the Existing Environment
Reports included as part of this attachment:
• Assessment of Benthic and Fisheries Impacts of Maintenance Dredging in Lough Mahon and the Lower River Lee, Aquatic Services Unit (March 2013) [included as part of Attachment B.2].
• Water Injection Dredging Tracer Study, Van Oord (July 2012) [included as part of Attachment D.3].
• Cork Dredge Spoil Disposal Site – Video and Benthic Grab Survey and Impact Hypothesis, Aquatic Services Unit (November 2004) [included as part of Attachment E.2 (i)]
• Cork Dredge Spoil Disposal Site, Irish Hydrodata (November 2013) [included as part of Attachment E.2 (i)]
• Port of Cork Maintenance Dredging Habitats Directive Assessment, Screening Statement, RPS (January 2014) [included separately within this Attachment F.1]
• Irish Hydrodata Bathymetric Surveys (September 2013) [included separately within this Attachment F.1]
• Integrated Report on Environmental Aspects of Cork Harbour Dredging, Port of Cork (March 2013) [included separately within this Attachment F.1]
• Sediment Pin Survey, Aquatic Services Unit (December 2011) [included separately within this Attachment F.1]
• Environmental Aspects of Cork Harbour Dredging, Van Oord (May 2012) [included separately within this Attachment F.1]
Port of Cork Maintenance Dredging Habitats Directive Assessment, Screening Statement
rpsgroup.com
Port of Cork Maintenance Dredging Dumping at Sea
Application
Habitats Directive Assessment Screening Statement
DOCUMENT CONTROL SHEET
Client: Port of Cork
Project Title: Maintenance Dredging Dumping at Sea Application
Document Title: Screening Statement
Document No: D01
No. of List of DCS TOC Text List of Figures This Document Appendices Tables Comprises: 1 1 61 2 1 1
Office of Rev Status Author(s) Reviewed By Approved By Issue Date Origin
Working E. Kelly/S. V01 S. Downes Limerick Draft Downes
Draft issued to V02 S. Downes M. McConnell Limerick 13.01.2014 client for review
V03 Final S. Downes M. McConnell G. Glasgow Limerick 21.01.2014
rpsgroup.com/ireland PoC Maintenance Dredging HDA Screening Statement
TABLE OF CONTENTS
1 BACKGROUND ...... 3 1.1 REGULATORY CONTEXT...... 4 1.1.1 Guidance ...... 5 1.1.2 Other Legislation ...... 6 2. SCREENING FOR APPROPRIATE ASSESSMENT ...... 7 2.1 PROJECT SETTING AND BACKGROUND ...... 8 2.2 NEED FOR DREDGING ...... 11 2.3 HISTORY OF DREDGING IN CORK HARBOUR ...... 13 2.4 NATURE OF THE MATERIAL TO BE DREDGED AND DISPOSED ...... 15 2-5 DISPOSAL OF DREDGE SPOIL ...... 18 2.6 DREDGING TECHNIQUES...... 26 3.0 IDENTIFICATION OF RELEVANT NATURA 2000 SITES AND COMPILATION OF INFORMATION ON THEIR QUALIFYING INTERESTS ...... 33 3.1 IDENTIFICATON OF RELEVANT NATURA 200 SITES WITHIN 15KM BUFFER...... 33 3.2 Screening Appraisal ...... 43 3.2.1 Brief Description of the Other Plans/Projects Which Could Give Rise to In- combination Effects ...... 51 3.2.2 Conclusions of assessment process...... 57 4.0 REFERENCES ...... 59 APPENDIX A...... 60 APPENDIX B...... 61
LIST OF FIGURES
Figure 2-1 Study Area, Cork City, Cork Harbour and Ringaskiddy...... 8
Figure 2-2 Maintenance Dredging Location Plan (Reference Table 2.4) ...... 21
Figure 2-3 Dump Site Location ...... 22
Figure 2-4 Port of Cork Approved Dump Site in relation to Natura 2000 sites...... 23
Figure 2-5 1999 Survey – Ground Type from Sidescan Sonar Interpretation (Source; IHL, Impact Hypothesis Update 2013)...... 24
Figure 2-6 2013 Survey – Shaded Relief Map, with 1999 data overlain...... 25
Figure 2-7 Trailing Suction Hopper Dredger Utrecht ...... 27
Figure 2-8 WID within City Quays Trigger Areas ...... 29
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Figure 2-9 WID within Tivoli Trigger Areas ...... 29
Figure 2-10 WID within Passage Trigger Areas...... 30
Figure 2-11 WID within Passage Trigger Areas...... 30
Figure 2-12 WID within Passage To Roche’s Point Areas...... 31
Figure 2-13 WID within Whitegate Trigger Areas...... 31
Figure 2-14 WID within Passage To Roche’s Point Areas...... 32
Figure 3-1 Natura 2000 sites within 15km Buffer...... 34
Figure 3-2 Natura 2000 Constraints Map surrounding proposed dredge areas and associated dump site ...... 37
Figure 3-3 Common Tern nesting locations, 2011 (Source: Breeding Bird Surveys, 2011 RPS) ...50
LIST OF TABLES
Table 2-1 Cork Harbour Main Characteristics...... 9
Table 2-2 Quantities Dumped at Site...... 15
Table 2-3 Sediment Chemistry Analysis...... 17
Table 2-4 Anticipated Dredge Volumes and subsequently Spoil Volumes 2014-2020 ...... 19
Table 2-5 Breakdown of quantities to be dredged per year (2014 – 2020) ...... 20
Table 2-6 Dump Site Location ...... 22
Table 3-1 SAC and SPA sites located within 15km Buffer zone ...... 33
Table 3-2 SPA and SACs screened out of the assessment...... 34
Table 3-3 Features of Interest within the Cork harbour SPA...... 35
Table 3-4 Features of Interest within the Great Island Channel SAC...... 36
Table 3-5 Description of Natura 2000 Sites Screened in for further assessment...... 38
Table 3-6 Description of Natura 2000 Sites Screened in for further assessment...... 40
Table 3-7 Characterisation of Impacts...... 43
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Table 3-8 Assessment of Residual Impacts ...... 53
Table 3-9 Integrity of the Site in Relation to Residual Impacts...... 57
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1 BACKGROUND
This report has been prepared by RPS on behalf of the Port of Cork. The purpose of the report is to determine the potential impacts, if any, of the proposed Maintenance Dredging Programme and associated dumping of dredge spoil at sea within the Port of Cork. The previous EPA Dumping at Sea Permit (EPA Ref: S0013-01) expired on the 31st December 2012 and therefore it is critical that this application is submitted to the EPA given the requirements for maintenance dredging which will arise in the summer of 2014.
The report is supported by focused field surveys (predominately aquatic) and data collated for the proposal both historically and newly acquired information from the Port of Cork and their associated sub-consultants.
The Port of Cork currently undertakes its maintenance dredging under a 5 year Dredging and Dumping License from the EPA. The Port has been using external contractors since 1997 under term contracts and currently Van Oord holds the contract from 2011-2017. It had been the practice that campaigns were carried out every two years but the Port has now managed to extend this practice to every three years. Certain identified areas within the area to be dredged have, in the past, become Trigger Areas for use to implement a Dredging Campaign. Also certain inaccessible areas for the Trailer Suction Hopper Dredging (TSHD) require dredging which is only possible with the use of WID. These areas would typically be adjacent to quay walls, under wharfs and Pontoon Marina structures. Some quay walls are of such a design and design depth that the robust nature of TSHD would not be feasible. The Trigger Areas are as a result of mud and silt being carried in suspension and being deposited where the flow slows down or changes direction. These areas are principally located at the Blackrock Castle Bend, Ringaskiddy Basin and the confluence of the North and South channels east of the Custom House. Certain areas have a buildup of silt as a result of being adjacent to mudflats. In addition severe storms, ship propellers and bow thrusters disturb the fairway slopes and mudflats and give rise to siltation in the basins and at the channel toe lines. This results in the Port of Cork having to mobilize the dredging contractor to attend to these relatively small quantities with significant spoil storage capacity still existing in fairway management buffers elsewhere. The Port of Cork therefore propose using their Multi-Cat vessel the “Denis Murphy” or a Van Oord WID vessel to undertake bed leveling in conjunction with TSHD at each campaign and between campaigns where necessary.
Multi- Cat – “Denis Murphy”
This vessel has several capabilities including that of a bed leveller and it has been used for this purpose by a number of contractors to date. If it is possible for the Port of Cork Company
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to use this vessel for some localized bed leveling to remove these Trigger Areas it would more than likely result in the extension of the period between dredging campaigns, bigger volumes in each campaign, more productive volume dredging for the contractor, less material in total being transported to the dump site, more efficient fairway and berth management and cost advantages for the Port of Cork.
WID Vessel
Bed levelling with water injection has a number of objectives, firstly to remove material within and near the dredge area into the collection area for the TSHD, secondly to remove areas above design depth (high spots) by transporting material into adjacent areas below design depths (low spots) and most importantly to access the areas described above as inaccessible . The use of WID vessels and their shallow draft allows these areas to be attended to where due to lack of available draft, location of existing mooring and maneuverability prohibits the use of TSHD. There are a number of these vessels available and some are demountable and are delivered by truck to site.
The various techniques will be expanded on further within this report.
This report will accompany the Port of Cork Dumping at Sea Application to the EPA but will act as a standalone document to the application for ease of consultation with the statutory agencies. The Port of Cork has not previously undertaken a Habitats Directive Assessment as part of any Maintenance Dredging Dumping at Sea Application as this was not a requirement at the time of their last application.
1.1 REGULATORY CONTEXT The European Council Directive 92/43/EEC on the Conservation of Natural Habitats and of Wild Flora and Fauna, better known as “The Habitats Directive”, provides the framework for legal protection of habitats and species of European importance. Articles (3) to (9) provide the legislative means to protect habitats and species of Community interest through the establishment and conservation of an EU-wide network of sites known as Natura 2000. This network of sites designated for nature conservation are comprised of Special Areas of Conservation (SACs) as designated under the EU Habitats Directive and Special Protection Areas (SPAs) designated under the Conservation of Wild Birds Directive (79/409/EEC) (better known as “The Birds Directive”).
Article 6 sets out provisions which govern the conservation and management of Natura 2000 sites. Article 6(3) and 6(4) of the Habitats Directive set out the decision-making tests for plans
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and projects likely to affect Natura 2000 sites. Article 6(3) establishes the requirement for Appropriate Assessment:
“Any plan or project not directly connected with or necessary to the management of the [Natura 2000] site but likely to have a significant effect thereon, either individually or in combination with other plans and projects, shall be subjected to appropriate assessment of its implications for the site in view of the site’s conservation objectives. In light of the conclusions of the assessment of the implication for the site and subject to the provisions of paragraph 4, the competent national authorities shall agree to the plan or project only after having ascertained that it will not adversely affect the integrity of the site concerned and, if appropriate, after having obtained the opinion of the general public”
The Habitats Directive promotes a hierarchy of avoidance, mitigation and compensatory measures.
1. First the project should aim to avoid any negative impacts on European sites by identifying possible impacts early in the planning stage, and designing the project in order to avoid such impacts. 2. Second, mitigation measures should be applied, if necessary, during the AA process to the point, where no adverse impacts on the site(s) remain. If the project is still likely to result in adverse effects, and no further practicable mitigation is possible, then it is rejected. 3. If no alternative solutions are identified and the project is required for imperative reasons of overriding public interest (IROPI test) under Article 6 (4) of the Habitats Directive, then compensation measures are required for any remaining adverse effect.
1.1.1 Guidance
This appropriate assessment has been carried out using the following guidance:
. Department of Environment Heritage and Local Government Circular NPW 1/10 and PSSP 2/10 on Appropriate Assessment under Article 6 of the Habitats Directive – Guidance for Planning Authorities March 2010.
. Appropriate Assessment of Plans and Projects in Ireland: Guidance for Planning Authorities, Department of the Environment, Heritage and Local Government 2009; http://www.npws.ie/en/media/NPWS/Publications/CodesofPractice/AA%20Guidance.p df
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. Managing Natura 2000 Sites: the provisions of Article 6 of the Habitats Directive 92/43/EEC, European Commission 2000; http://ec.europa.eu/environment/nature/natura2000/management/docs/art6/provision_o f_art6_en.pdf
Assessment of Plans and Projects Significantly Affecting Natura 2000 Sites: Methodological guidance on the provisions of Article 6(3) and (4) of the Habitats Directive 92/43/EEC. http://ec.europa.eu/environment/nature/natura2000/management/docs/art6/natura_200 0_assess_en.pdf
. Guidance document on Article 6(4) of the 'Habitats Directive' 92/43/EEC – Clarification of the concepts of: alternative solutions, imperative reasons of overriding public interest, compensatory measures, overall coherence, opinion of the commission. http://ec.europa.eu/environment/nature/natura2000/management/docs/art6/guidance_a rt6_4_en.pdf
. Guidance document on the implementation of the birds and habitats directive in estuaries and coastal zones with particular attention to port development and dredging. http://ec.europa.eu/environment/nature/natura2000/management/docs/guidance_doc.p df
. European Communities (Birds and Natural Habitats) Regulations 2011. http://www.npws.ie/media/npwsie/content/files/Birds%20and%20Habitats%20Regulatio ns%20SI%20477%20of%202011.pdf
Based on these guidelines, the assessment process is a four-staged approach. An important aspect of the process is that the outcome at each successive stage determines whether a further stage in the process is required.
1.1.2 Other Legislation
Natural Heritage Areas (NHA) are sites of national significance, proposed Natural Heritage Areas (pNHA) are sites that have been proposed but not formally designated. When formally designated, a pNHA is legally protected from damage under Irish legislation in the form of the Wildlife (Amendment) Act 2000. However, as this Appropriate Assessment report deals only the Natura 2000 sites the NHAs and pNHAs are not considered further in this study, other than in the description of the study area. The EU Birds Directive (Council Directive 79/409/EEC on the Conservation of Wild Birds) is the main mechanism for protecting, management and control of bird species and defines rules
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for their exploitation. According to Article 4 of the Birds Directive “species mentioned in Annex I shall be the subject of special conservation measures concerning their habitat in order to ensure their survival and reproduction in their area of distribution”. The key element of the Birds Directive is that it provides for the creation of the Special Protection Areas (SPAs) for the protection of Annex I species as well as for regularly occurring migratory species not listed in Annex I. The Birds Directive is implemented in Ireland under the Wildlife Act (1976) and the Wildlife (Amendment) Act (2000).
2. Screening for Appropriate Assessment
Screening determines whether appropriate assessment is necessary by examining:
1. Whether a plan or project can be excluded from AA requirements because it is directly connected with or necessary to the management of a Natura 2000 site.
2. Whether the project will have a potentially significant effect on a Natura 2000 site, either alone or in combination with other projects or plans, in view of the site’s conservation objectives.
Screening involves the following:
Description of plan or project
Identification of relevant Natura 2000 sites, and compilation of information on their qualifying interests and conservation objectives
Assessment of likely effects – direct, indirect and cumulative – undertaken on the basis of available information as a desk study or field survey or primary research as necessary
Screening Statement with conclusions
The assessment of likely significant effects is based on the likelihood and significance of any effects from both the dredging campaign itself and the associated dumping of the dredge spoil at sea on each Natura 2000 site’s qualifying features, particularly with reference to the relevant conservation objectives. In this context the likelihood depends on whether there is the opportunity and pathway for the effect to occur and the significance is regarded as the effect on the susceptible qualifying features of the site(s). If the effects are deemed to be significant,
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potentially significant, or uncertain, or if the screening process becomes overly complicated, then the process must proceed to Stage 2 (AA). Thus, this Screening required a review of all Natura 2000 sites within close proximity to both the dredge locations and the associated approved dump site. It involved identifying whether sites should be included in Stage 2 of the AA. A 15km buffer zone was chosen as a precautionary measure, to ensure that all potentially affected Natura 2000 sites are included in the screening process, which is in line with Appropriate Assessment of Plans and Projects in Ireland – Guidance for Planning Authorities produced by the Department of the Environment, Heritage and Local Government (DEHLG, 2009). The precautionary approach used will ensure that all potentially affected Natura 2000 sites were included in the screening process. This means that, unless it can be shown that there is no likely significant effect on a Natura 2000 site, such an effect must be assumed.
2.1 PROJECT SETTING AND BACKGROUND
The Port of Cork is the key seaport in southern Ireland, comprising of a significant natural harbour and a river estuary at the mouth of River Lee located in County Cork (Figure 2.1). The Port of Cork are responsible for port operations, navigation and safety in the port and carry out maintenance dredging to maintain navigable depths in the port facilities including Cork City Berths, Ringaskiddy and Cobh Deepwater Quay (Figure 2.1). Cork Harbour is a natural harbour and river estuary at the mouth of the River Lee in the south of Ireland with extensive intertidal areas of high ecological value.
Figure 2-1 Study Area, Cork City, Cork Harbour and Ringaskiddy
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Cork Harbour is further characterized by a large tidal range, during spring tide up to 23% of the water in the estuary flows to and from the sea twice a day (Table 2-1). In summer hardly any fresh water enters the estuary, in the winter the river discharges rise significantly, to up to 65 m3 of water from the River Lee alone in January. (Van Oord, May 2012)
Table 2-1 Cork Harbour Main Characteristics Source: ECI Environmental change Institute, National University of Ireland
Estuary area 8.585 hectares Estuary length 17.17 km Maximum width 6.14 km Width at mouth 1.65 km Main channel width at mouth 1.65 km Maximum depth 29 m Max depth at mouth 29 m Population adjacent to estuary 180,000 Tidal prism 150 x 106 m3 Volume 642 x 106 m3 Ratio prism to volume 0.23 Tidal range (spring) 4.2 m Tidal range (neap) 2.1 m
The River Lee flows through the Port of Cork and enters the Atlantic Sea south of Roches Point. The Harbour can, for convenience, be divided into two distinct areas – the deepwater section from the entrance to Passage West is called the Lower harbour whilst from Passage to the City Quay is known as the Upper Harbour. The Lower Harbour is a well sheltered, virtually land locked basin embracing some 3,500 hectares of water and has two large islands within the centre of this area- one Haulbowline Island, 26 hectares in extent and the other Spike Island with 42 hectares. The Upper harbour contains a large number of port facilities which are located at the City Quays and Tivoli. These facilities are served by a dredged channel extending some 5 miles upriver from Lough Mahon. The principal tributaries of the Lee are the Glashaboy River at Dunkettle, the Douglas River at Lough Mahon, the Owenacurra River at Ballinacurra and the Owenaboy River at Crosshaven.
PORT FACILITIES
Navigation Channel In the Lower harbour the channel between Roches Point and Passage is a natural deepwater channel except at the 3 locations where dredging is carried out to increase the available depth. The bar at Roches Point is dredged to provide a depth of 12.9 metres C.D and the Spit Bar and Ringaskiddy Bend are both dredged to provide- 11 metres C.D. The basin at Ringaskiddy is also dredged to provide advertised depth of 11 metres C.D. In the Upper harbour i.e. Passage to Cork the entire navigation channel is man-made and dredging has been carried out in the stretch since 1840. In 1994 the channel was deepened to provide an
IBE0887.00 Rev V03 PoC Maintenance Dredging HDA Screening Statement advertised depth of 6.5 metres C.D. between Passage and Tivoli Berths. The advertised depth in the channel between Tivoli Berths and Cork City quays is 5.2 metres C.D.
City Quays BERTH LENGHT DEPTH Albert Quay 135.0m 5.63 South Jetties 411.5m 8.8m South Deepwater Quay 194m 6.0m Penrose Quay 146m 3.6m Horgan’s Wharf 205.7m 8.8m Custom House Quay, North 176.9m 7.3m
Tivoli BERTH LENGHT DEPTH Roll-on Roll-off 125m 5.0m Terminal ORE/General 170m 8.8m Purpose Berth Quigley’s Container Terminal 155m 8.8m Bulk Liquid Berth 115.8m 6.0m
Ringaskiddy BERTH LENGHT DEPTH Deepwater Terminal 485.0m 13.4m Roll-on Roll-off 180m 9.2m Terminal (No. 1 Ramp) Roll-on Roll-off 150m 8.5m Terminal (No. 2 Ramp) Adm Jetty 259.1m 9.6m
Cobh BERTH Length Depth Deep Water Quay Lenght alongside: 6.1m 183m Lenght with Pontoon: 9.1m 350m
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Lower Harbour
BERTH Length Depth No. 1 Oil Jetty Length alongside 13.1m 365.8m No. 2 Oil Jetty Length alongside 10.2m 106.7m Passage West Length alongside 9.0m 274.3m
2.2 NEED FOR DREDGING
Maintenance dredging is needed within the berths, on the approaches to the berths, in navigational channels and the harbour basins in the Port of Cork. The (river) bottom in the designated areas shall be dredged to ensure that the design depths are provided throughout the above described area. The design depths will be the advertised depth plus a specified additional buffer depth to cater for future siltation. The method of dredging and transporting material shall be such as to avoid deposition of material in navigable channels.
Sedimentation and Accretion within the harbour
The Harbour is a comparatively stable system in regard to estuary dynamics with only localised areas of erosion and accretion. Throughout its 13 miles in length the navigation channel and basins are subjected to influences which give rise to siltation from different sources.
In general these can be summarised as follows:-
(i) Mud and silt particles are carried in suspension down the Lee and by its tributaries, into the shipping channels and berths where they lose suspension and deposit where the flow slows.
(ii) Ships’ displacement in relatively narrow navigation channels causes erosion of the adjacent mudflats at certain stages of the tide which results in siltation on the channel edges.
(iii). Severe winter storms disturb the fairway slopes and mudflats and give rise to siltation in the basins and on the channel tow lines.
(iv). Propeller and bow thrusters’ action of the ships as they enter or exit berths induces localised high velocities which give rise to erosion in some areas and accretion in others leading to the creation of high spots.
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Siltation in navigable areas is generally accommodated within the buffer zones of varying depth, which are established for this purpose and from where it is removed by maintenance dredging campaigns.
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2.3 HISTORY OF DREDGING IN CORK HARBOUR
Pre 1996
Prior to 1996 maintenance dredging within the Port was carried out by in-house plant owned by the Port Authority.
During this period the approximate annual dredging requirement was 129,000 m3
1997-2001
During this period maintenance dredging was carried out by HAM Dredging Ltd. Dredging was carried out using a trailer suction hopper dredger (TSHD) assisted by a plough and/or water injection craft to carry out bed levelling operations. In carrying out the bulk dredging the THSD created a series of troughs and the attendant craft was then used to level the high spots into these troughs thus entering that the TSHD kept operating at maximum production. The attendant craft was also used to pull spoil areas which were inaccessible for the TSHD and also from areas in which the TSHD was not permitted to operate. This was necessary for instance at gravity type quay walls and other quays where the structure could be undetermined or put at risk by over dredging.
Dredging was generally carried out to 50cm below the advertised navigational depth thus providing a buffer to cater for future siltation and for bed levelling of high spots between campaigns.
During this period the average annual requirement for dredging also carried out by Port of Cork was approx 100,000 m3. In addition dredging was undertaken in some areas by Cork City Council with an annual average of approx 70,000m3 giving and overall annual dredging requirement in the harbour of approx 170,000 m3.
2003 to 2007
During this period maintenance dredging was carried out by Dutch Dredging. Dredging was again carried out by Trailer Suction Hopper Dredger which was assisted by the Port of Cork’s Bedleveller the ‘Denis Murphy’.
During this period 2 dredging campaigns were undertaken;
2003-486,124 tonnes (373,942 m3)
2005-174,172 tonnes (133,979 m3)
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2008-2013
The Port of Cork has been using external dredging contractors to carry out maintenance dredging since 1997 and it has become the practice that campaigns are carried out every two years.
It has been the case in the past that certain areas within the harbour have silted at a faster rate than others and as such the need to dredge these areas to maintain navigable depth has been the trigger for implementation of a dredging campaign. These areas are principally located at the Blackrock Castle bend, Ringaskiddy Basin and the confluence of the North and South channels east of the Custom House. In addition severe storms, ship propellers and bow thrusters can disturb the fairway slopes and mudflats and give rose to siltation in the basins and at the channel tow lines.
This situation has led to inefficiencies in the dredging works as the Port has had to initiate a dredging campaign to attend relatively small quantities in these areas while significant spoil storage capacity still exists in fairway management buffers elsewhere.
In 2008 the Port of Cork prepared a Dredging Management Plan (2008-2012). Within this dredging management plan the Port if Cork proposed to undertake bed levelling operations between main dredging campaigns to make better use of the available storage capacity in the main fairways. Levelling operations were to be undertaken either by ploughing or the use of water injection techniques. The Port own and operate a Multi-Cat “Denis Murphy” which has bed levelling capabilities and which has been installed with dredging control software. This vessel has, with the approval of DCMNR, been used to carry out bed levelling throughout the harbour.
Van Oord UK was awarded the maintenance dredging contract to undertake Trailer Suction Hopper Dredging (TSHD) within the Port and its environs throughout the lifetime of the campaign. This appointment was split into two separate contracts the second of which commenced in late 2010. During the tender stage Van Oord identified the opportunity to carry out maintenance requirements with Water Injection Dredging (WID) only, however at the time the dredge licence only allowed limited use of this method. Give that WID is recognised to have a lower cost, carbon footprint and has the potential to provide a sustainable alternative to traditional dredging methods. It was accepted by all statutory parties that a test regime should be carried out to determine the effects of WID on the estuary system.
2008 - 253,848m3
2007 - 272,075m3
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Table 2-2 Quantities Dumped at Site Year Quantity (M3)
1978-1999 6,730,000
2000 149,854
2003 441,931
2005 133,979
2008 253,848
2011 272,075
2.4 NATURE OF THE MATERIAL TO BE DREDGED AND DISPOSED
Physical Characteristics
The material to be dredged generally comprises predominantly silt with some sand content. On average silt content is approx 80%. The material to be dredged comprises fine sandy silt, fine medium sand, silty fine sand, sandy fine to coarse sub-rounded gravel, occasional cobbles and shells, weak moderately-weak fine grained sandstone. The approximate composition is Rock/Gravel 4%, fine sandy silt 96%.
Chemical Analysis (Contamination of sediments)
The Aquatic Services Unit (ASU) undertook sediment sampling for the Port of Cork (POC) on June 19th 2013 as part of its maintenance dredging programme in Cork Harbour. Surface sampling was undertaken at the City Quays, Lough Mahon, Passage West, the former Verolme Dockyard and Ringaskiddy. Sediment depth cores were taken at Verolme.
The samples were taken with a stainless steel van Veen grab (~0.048m2) and were sent for analysis to the NLS (National Laboratory Service) in Leeds. The samples were processed at Leeds and forwarded to the NLS Lab in Llanelli in Wales, which specialises in and is accredited for marine sediment analysis using the UK National Marine Monitoring Programme (NMMP) protocols.
The results indicated high levels of nickel and chromium at several sites. This was in line with previous sampling carried out by the Port of Cork in the past at certain sites with the highest levels in areas where these metals had been high in the past, e.g. at the City Quays. However, it was also noted that the levels were higher than previously noted in Lough Mahon (e.g. at LM7) and it was speculated that
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Maintenance Dredging HDA Screening Statement this might have been linked to the Water Injection Dredging which had been undertaken the previous autumn (2012) from the City Quays to Tivoli.
ASU were requested to comment on these trends in the results and after some preliminary analysis postulated that because nickel and chromium were important components in the making of stainless steel, that the possibility existed that perhaps the levels of these two metals might have been influenced by the use of the ASU grab. ASU considered that this was unlikely to have been a significant factor affecting the results but also noted that the two metals were the most significantly correlated in the results (r2 >0.92) which might point to a similar provenance for the two metals. Against this however, both metals are noted in the scientific literature as being strongly correlated in some geologies, so the possibility that both metals co-occur in the fine sediment fraction in Cork Harbour might also account for this significant correlation.
Following further discussions repeat sampling was undertaken in November 2013 by ASU in order to further inform the trends in results.
Repeat Sampling and Repeat Analysis November 2013
OVERALL CONCLUSIONS
An analysis of the data would suggest that the National Laboratory Service (NLS) has produced good to high quality results and has probably contributed very little to the variation noted between these various datasets.
There was appreciable variation noted in the concentration in metals between all three grabs (A, B and C) including nickel and chromium. Some of this variation is probably related to small scale patchiness in the heavy metal burden in sediments, however, that is unlikely to be the full explanation and some influence form the grabs themselves in the case of nickel and chromium cannot be entirely ruled out.
The repeat analysis of the June samples at five sites and the comparison with the repeat results in November, would suggest that the chromium and nickel levels reported in the original June samples at Site R5 and LM7 and those of chromium reported from R2 in the same samples would appear to have been unrepresentative and over estimates of the actual levels of these metals at those sites. The comparatively close agreement between the results of the repeat analysis of the June samples and the repeat November sampling at these sites would suggest that the results from chromium and nickel in these two datasets would be a more reliable measure of the levels of these two metals at those sites.
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The following (Table 2-3) summarises the exceedances from the Dredging Guidelines Upper and Lower Level.
Table 2-3 Sediment Chemistry Analysis
Sample Date Metal Upper Lower
November 2013 (15 sites analysed) Arsenic 8 sites
Cadmium 1 site
Chromium 6 sites
Nickel 6 sites 9 sites
June 2013 – (Reanalysis) (5 sites analysed) Arsenic 4 sites
Chromium 2 sites
Copper 1 sites
Nickel 2 sites 2 sites
Zinc 1 site
June 2013 (13 sites analysed) Arsenic 5 sites
Chromium 10 sites
Copper 4 sites
Lead 2 sites
Nickel 8 sites 5 sites
Zinc 4 sites
A total of 6 metals exceeded the Dredging Guideline Lower Levels in at least one sampling location with just Nickel and Zinc exceeding the Upper Levels. Only Nickel exceeds the Upper Guidance Level in the November 2013 re-analysis at 6 of the sites.
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Metal concentrations which are below the Lower Level represent sediment with “no contamination” (Marine Institute 2006). However, it would be expected in an industrial harbour such as Cork Harbour that samples would exceed the Lower Level.
Within an estuary such as Cork Harbour, with large volumes of industry and heavy shipping activity, it would be expected that the concentration of metals and organic parameters would be elevated above uncontaminated, natural background, ‘pristine’ levels. In the majority of sampling locations the Dredging Guideline Lower Level were exceeded but the Dredging Guideline Upper Level and in general were not exceeded. This indicates that the sediment is marginally contaminated, which is not unexpected for an industrial harbour. These results do not pose a significant threat to the qualifying interest features of the SPA or SAC in terms of impacts to water quality.
Radiological Tests
The Radiological Protection Institute of Ireland requested the Radiological analyses of sediments from four separate areas within the Cork harbour namely Blackrock Castle, Ringaskiddy, Crosshaven and Whitegate. The samples were taken by Enterprise Ireland (Shannon Aquatic Toxicity Laboratory) and were received by the Institute on 19th June 2002. The results indicate that dumping of these materials will not result in a Radiological hazard.
Further sampling and testing was carried out as part of the Dredging Management Plan 2008-2012 in areas designated by the Radiological Protection Institute one sample was taken from each of the following areas, City Quays, Tivoli to Bouy No.2 Ringaskiddy Basin area and the Refinery Jetty area again the results did not indicate any radiological hazard.
2-5 DISPOSAL OF DREDGE SPOIL
METHOD OF DISPOSAL
The disposal of material at sea is permitted only if no other beneficial use of financially viable alternative for the disposal of the material is available. The OSPAR Guidelines list three possible uses:-
Engineering uses, i.e. land creation, fill material etc. Agricultural and product uses. Environmental enhancement
The silt and mud dredging during the maintenance campaigns contain none of the physical or chemical properties required for any of the above uses. This leaves disposal at sea as the only
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The material will be dumped at a sea at the approved Port of Cork Dump site by Trailer Suction Hopper Dredging.
DISPOSAL SITE
It is proposed that the dredge spoil shall be disposed of at the current Port of Cork disposal site off Roches point and south of Power Head. The location of the disposal site is illustrated in Figure 2-5.
Regular disposal of spoil at this site has been carried out since 1978. Approximately, 7 million Cu.M have been dumped since regular dumping began.
It is anticipated that the following total volumes will be dredged and subsequently deposited at the dump site between the years 2014 – 2020.
Table 2-4 Anticipated Dredge Volumes and subsequently Spoil Volumes 2014-2020 Volumes / Tonnages Being Applied For
For Each Main Campaign Years 2014, 2017 and 2020
Main Loading Areas by Trailer Suction Hopper Dredging
Volume Wet Tonnage Location (m3) (t) City Quays Horgan's Wharf 4,100 4,510 City Quays North Deepwater Quay 2,200 2,420 City Quays Albert Quay 1,250 1,375 City Quays South Jetties 5,750 6,325 City Quays South Deepwater Quay 1,250 1,375 Fairway Bottom of Lough 67,600 74,360 Tivoli Quigley Berth 5,000 5,500 Tivoli Container Berth 750 825 Tivoli RoRo Berth 1,250 1,375 Tivoli Oil Jetty 1,250 1,375 Lough to Passage 200,100 220,110 Haulbowline Industries Berth 7,000 7,700 Ringaskiddy Basin 35,000 38,500 Ringaskiddy Deepwater Berth including R0-Ro 10,500 11,550 Whitegate Berths and Approaches 3,000 3,300 Passage to Roche's Point 5,000 5,500 Cobh Circle 1,000 1,100
352,000 m3 387,200
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For Each Interim Campaign Years 2015 & 2016 then 2018 & 2019
Trigger Areas / Local Area Dredging by Water Injection / Bed Levelling
Volume Wet Tonnage Location (m3) (t) Trigger Areas City Quays Horgan's Wharf total below total below City Quays North Deepwater Quay total below total below City Quays Albert Quay total below total below City Quays South Jetties total below total below City Quays South Deepwater Quay total below total below Bottom of Lough total below total below Tivoli Quigley Berth total below total below Tivoli Container Berth total below total below Lough to Passage total below total below Haulbowline Industries Berth total below total below Ringaskiddy Deepwater Slot total below total below Ringaskiddy Slipway and Pier total below total below NMCI Loading Area and Drop Pool total below total below Local Area Dredging National Maritime College of Ireland Landing Area and Drop Pool total below total below Ringaskiddy Slipway and Pier total below total below Boat Camber at Cobh total below total below 20,000 22,000
Figure 2-2 provides a location map indicating the location of these dredge locations as per the various techniques outlined in Table 2-5.
Table 2-5 Breakdown of quantities to be dredged per year (2014 – 2020)
Breakdown of Quantities per Year
Wet Tonnage Year Volume (m3) (t) Method of Dredging Trailer Suction Hopper 2014 352,000 387,200Dredging 2015 20,000 22,000 Bed Levelling 2016 20,000 22,000 Bed Levelling Trailer Suction Hopper 2017 352,000 387,200Dredging 2018 20,000 22,000 Bed Levelling 2019 20,000 22,000 Bed Levelling Trailer Suction Hopper 2020 352,000 387,200Dredging Totals 1,136,000 1,249,600
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Figure 2-2 Maintenance Dredging Location Plan (Reference Table 2-4)
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This appropriate assessment relates to the proposed dredging and subsequent dumping at sea, which will take place as part of the application for a maintenance dumping at sea permit application for the Port of Cork. Following a review of the Dump Site in relation to its proximity to any Natura 2000 site for this screening assessment and the undertaking of an impact hypothesis by Irish Hydrodata Ltd (IHD)1 on behalf of the Port of Cork this element of the overall project (Potential impact from the disposal of dredge spoil at the dump site) was screened out from any further assessment. As can be seen from Figure 2-4 the dump site is not located within close proximity to any Natura 2000 site and does not pose a significant risk or permanent effect to any of the qualifying features of the sites located surrounding the Port of Cork. The Cork dredge spoil disposal site co-ordinates are presented below in Table 2-6 and displayed as per the admiralty chart on Figure 2-2. The site was reduced in size in December 1996 and all dumping since then has occurred in the smaller site (See Figure 2-2).
Table 2-6 Dump Site Location
Figure 2-3 Dump Site Location
1 Cork Dredge Spoil Disposal Site – Impact Hypothesis Update 2013
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Figure 2-4 Port of Cork Approved Dump Site in relation to Natura 2000 sites.
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The impact hypothesis took the form of a mulitbeam echosounding survey which would identify the expanse of areas within the disposal site which consist of exposed bedrock and surface sediments. This information was then compared to results from earlier surveys to see if the dumped material was accumulating at the dumpsite or causing any long term, permanent effects on the surrounding Natura 2000 sites. The outline of the rock/sediment areas as interpreted in 1999 from the sidescan sonar survey (See Figure 2-5) which shows that a substantial area consisted of bedrock.
Figure 2-5 1999 Survey – Ground Type from Sidescan Sonar Interpretation (Source; IHL, Impact Hypothesis Update 2013)
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Between the multibeam surveys of 2008 and 2013, some 272,075m3 of material was dumped at the site. A visual comparison of the shaded relief maps from the surveys of 2008 and 2013 shows little of no change in the expanse of sediment on the seabed surface within the dump site between those years. Figure 2-6 shows the outline of the rock/sediment areas as interpreted from the sidescan sonar survey of 1999 superimposed on the shaded relief map from the multibeam survey of 2013.
Figure 2-6 2013 Survey – Shaded Relief Map, with 1999 data overlain
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A more rigorous comparison of the surveys of 2008 and 2013 was undertaken by comparing depth profiles. Digital Terrain Models (DTM) were created for each survey and profiles extracted. The profiles also demonstrate no appreciable difference between the surveys of 2008 and 2013.
In the years 1978 to 1999, approximately 3,226,000m3 of dredged material was dumped in the reduced dump site area. A total of 979,612m3 was dumped during the years 2000 to 2008 (before the survey of Sept. /Oct. of that year) and a total of 272,075m3 was dumped in the period after the survey of 2008.
A comparison of the interpretation of the sidescan survey of 1999 with the shaded relief map from the multibeam survey of 2008 (almost 1 million m3 of material dumped during this period) would not indicate any major accumulation of dumped material to have occurred during that nine year period.
A comparison of the shaded relief maps from the surveys of 2008 and 2013 (over 272,000m3 of material dumped during this period) shows little or no change to bathymetry to have taken place during that five year period. This is borne out by comparison of depth profiles from these surveys.
The dump site consists mainly of exposed bedrock with patches of sediment. Geophysical survey data from the INFOMAR survey of 2008 shows the sediment thickness to be typically about 1m, occasionally reaching 2m.
2.6 DREDGING TECHNIQUES
Two methods of dredging will be employed by the Port of Cork;
Trailing Suction Hopper Dredging supported by Bed Levelling and / or Water Injection Dredging in respect of main campaigns
Water Injection Dredging or bed levelling in the Trigger and Local Access Dredging (LAD) Areas between campaigns
A Trailing Suction Hopper Dredger is a vessel that is suited for deep-sea navigation with the ability to load material into its own hopper by means of centrifugal pump(s) and suction pipe(s). Figure 2-7 indicates a possible layout of a TSHD. Trailing Suction Hopper Dredgers belong to the type of non- stationary dredgers. This means that TSHD are required to sail during dredging operations. This is where the dredging vessel drags a pipe on the river bed and material is sucked up into the hold of the vessel. The material settles in the hold and excess water from the suction operation is returned to the sea as the hold reaches capacity. Once the hold is full the vessel proceeds to the approved spoil dump site and discharges the material through bottom doors in her hull that open to release the hold contents. The vessel continuously passes over the area to the dredged gradually increasing the depths to the required levels. This method of dredging has been employed by the Port of Cork for
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Figure 2-7 Trailing Suction Hopper Dredger Utrecht
Water Injection Dredging (WID)
WID involves jetting large quantities of water under low pressure into the sediment, generally slit or very fine sand, to fluidise the settled material. This process breaks down the cohesion of the sediment to form a fluid dense sediment layer which then moves under the influence of gravity and density gradients. The aim of this type of dredging is not to raise sediments into the water column, but to keep them restricted to the nearbed area. Where properly applied, environmental effects due to suspended solids are greatly minimised as they are restricted to the vicinity of the seabed. WID can also be relatively flexible in confined areas such as harbours, marinas and around berths and pontoons due to the small size of the dredging plant. WID is considered to be beneficial to sediment management in a given area since the sediment is retained within the local system rather than taken out of that system and disposed of at sea, possibly in an area that does not have similar sediment properties to the maintenance dredge material. Within the Port of Cork it is proposed to use WID to;
1. Enable dredging at close proximity to Quay Walls. 2. WID in the interim periods to remove trigger areas such as Castle Bend, End of Custom House Quays. 3. WID in and under Marina at South Custom House Quay. 4. Inaccessible Berths such as Boat Harbour Cobh, John F Kennedy Pier Cobh, Haulbowline Industries at Passage and Quigley’s Berth at Tivoli.
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Bed Levelling
This consists of a blade or bar which is pulled behind a suitable tug or work boat, PoC “Denis Murphy” is designed as such. The method can be used for direct dredging over short distances and for levelling off the bed to the desired depth when a Trailer or other Dredger is operating. It may also be used to pull away material located close to quay walls and other places where a trailer cannot reach into a more accessible area. It is also used to accumulate material in bulk for the Dredger to Collect.
TRIGGER AREAS. Trigger Areas have historically indicated the need to begin a Dredging Campaign. The Build-up of Sediment firstly happens in these areas:
1. Confluence of North and South Channels of River Lee. This is at the tip of the island where the North and South Channels meet. (Custom House ) 2. Blackrock Castle Bend. Build up in this area is generally at the toe of the slope and if left unattended would restrict available depth at this tight pinch area.
Management of these Trigger areas by Bed levelling or WID prevents the need to commence a full dredge campaign.
Local Area Dredging (LAD) will include the following areas and will be additional to the Trigger Areas; these LAD areas will be included in the 20,000m3 and will enable PoC to attend to access provision at these areas. 1. National Maritime College of Ireland Landing Area and Drop Pool 2. Ringaskiddy Slipway and Pier 3. Boat Camber at Cobh.
Figures 2-8 – 2-14 provides an indication of the locations (Trigger Areas) where WID will be employed by the Port of Cork during the lifetime of the Dumping at Sea Permit.
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Figure 2-8 WID within City Quays Trigger Areas
Figure 2-9 WID within Tivoli Trigger Areas
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Figure 2-10 WID within Passage Trigger Areas
Figure 2-11 WID within Passage Trigger Areas
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Figure 2-12 WID within Passage To Roche’s Point Areas
Figure 2-13 WID within Whitegate Trigger Areas
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Figure 2-14 WID within Passage To Roche’s Point Areas
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3.0 IDENTIFICATION OF RELEVANT NATURA 2000 SITES AND COMPILATION OF INFORMATION ON THEIR QUALIFYING INTERESTS
3.1 IDENTIFICATON OF RELEVANT NATURA 200 SITES WITHIN 15KM BUFFER
The Habitats Directive contains a list of habitats (Annex I) and species (Annex II) for which SACs must be established by Member States. Similarly, the Birds Directive contains lists of important bird species (Annex I) and other migratory bird species for which SPAs must be established. Those that are known to occur at a site are referred to as ‘qualifying interests’ and are listed in the Natura 2000 forms which are lodged with the EU Commission by each Member State. A ‘qualifying interest’ is one of the factors (such as the species or habitat that is present) for which the site merits designation. Three Natura 2000 sites are located within a precautionary distance of 15 kilometres of the approved dump site which is used by Port of Cork. The full list of these sites is shown in Table 3-1 together with Figure 3-1. The Department of the Environment, Heritage and Local Government guidance on appropriate assessment states that a distance of 15km is currently recommended in the case of plans. For projects, the distance could be reduced however, given the sensitivity of the ecological receptors within the study area a precautionary approach of 15km has also been adopted for this project. Table 3-1 and Figure 3-1 outlines the SACs and SPAs within a 15km Buffer.
Table 3-1 SAC and SPA sites located within 15km Buffer zone Code Site SPA Code 004030 Cork Harbour SPA SAC Code 001058 Great Island Channel SAC Code 002170 Blackwater River SAC
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Figure 3-1 Natura 2000 sites within 15km Buffer
The proposed dredging works are located within close proximity to the Cork Harbour SPA and the Great Island Channel SAC and therefore form the key areas of concern for this appropriate assessment. However, the remaining SAC (Blackwater River SAC) has been screened out due to the following;
It has no direct hydrological connectivity to the area of the proposed dredging activities or associated approved dump site No direct terrestrial or aquatic linkage exists between the proposed dredging locations and or the associated dump site and the Natura 2000 site habitats and species for which it is designated It is at a sufficient distance away from the site (touches the 15km boundary) to remove any potential risk to the qualifying interest features (See Figure 3-1)
Therefore this SAC is screened out from any further assessment
Table 3-2 SPA and SACs screened out of the assessment Code Site SAC Code 002170 Blackwater River SAC
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Details in relation to the qualifying features of the Cork Harbour SPA and Great Island Channel SAC are described in Table 3-3 – 3-6. The information contained in these tables is based on the findings in Ireland’s Article 17 Report to the European Commissions ‘The Status of EU Protected Habitats and Species in Ireland’ (NPWS, 2013). Every six years, Members States of the European Union are required to report on the conservation status of all habitats and species listed on annexes of the Habitats Directive. The 2013 conservation status assessment uses a format agreed at a European level. There is no similar information collated for SPAs in terms of National Conservation Status. Equally no Conservation Management Plan exists for the two main Natura 2000 sites which are applicable in this investigation. In the absence of site specific management plans the generic Site Conservation Objectives for the Great Channel Island SAC and the Cork Harbour SPA were used. Coupled with this the NPWS Natura 2000 site synopsis forms were also utilised all of which can be found in Appendix A. The features of interest and Conservation Objectives of the Natura 2000 sites are described in Tables 3-5 & 3-6.
Cork Harbour SPA (Site Code 004030) The site has twenty-four features of interest2: Table 3-3 Features of Interest within the Cork Harbour SPA
Code Feature of Interest Habitats A004 Little Grebe (Tachybaptus ruficollis) A005 Great Crested Grebe (Podiceps cristatus) A017 Cormorant (Phalacrocorax carbo) A028 Grey Heron (Ardea cinerea) A048 Shelduck (Tadorna tadorna) A050 Wigeon (Anas penelope) A052 Teal (Anas crecca) A054 Pintail (Anas acuta) A056 Shoveler (Anas clypeata) A069 Red-breasted Merganser (Mergus serrator) A130 Oystercatcher (Haematopus ostralegus) A140 Golden Plover (Pluvialis apricaria) A141 Grey Plover (Pluvialis squatarola) A142 Lapwing (Vanellus vanellus) A149 Dunlin (Calidris alpina) A156 Black-tailed Godwit (Limosa limosa) A157 Bar-tailed Godwit (Limosa lapponica) A160 Curlew (Numenius arquata) A162 Redshank (Tringa totanus) A179 Black-headed Gull (Chroicocephalus ridibundus) A182 Common Gull (Larus canus) A183 Lesser Black-backed Gull (Larus fuscus) A198 Common Tern (Sterna hirundo) A999 Wetlands & Waterbirds
2 NPWS (2011) Conservation objectives for Cork Harbour SPA [004030]. Generic Version 4.0. Department of Arts,Heritage & the Gaeltacht.
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Cork Harbour is a large, sheltered bay system, with several river estuaries - principally those of the Rivers Lee, Douglas, Owenboy and Owennacurra. The SPA site comprises most of the main intertidal areas of Cork Harbour, including all of the North Channel, the Douglas River Estuary, inner Lough Mahon, Monkstown Creek, Lough Beg, the Owenboy River Estuary, Whitegate Bay and the Rostellan and Poulnabibe inlets.
Great Island Channel SAC (Site Code 001058)
The site has four Features of Interest3:
Table 3-4 Features of Interest within the Great Island Channel SAC
Code Species & Code 1130 Estuaries 1140 Mudflats and sandflats not covered by seawater at low tide 1320 Spartina swards (Spartinion maritimae) 1330 Atlantic salt meadows (Glauco-Puccinellietalia maritimae)
3 NPWS (2011) Conservation objectives for Great Island Channel SAC [001058]. Generic Version 3.0. Department of Arts, Heritage & the Gaeltacht.
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Figure 3-2 Natura 2000 Constraints Map surrounding proposed dredge areas and associated dump site
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Table 3-5 Description of Natura 2000 Sites Screened in for further assessment
Natura 2000 Site Location Qualifying Interests Site Sensitivity Conservation Status, Threats5 Trend in Conservation Status4 Little Grebe Recreational activities The favourable conservation Extensive areas of estuarine habitat (Tachybaptus are high in some areas of status of a species is achieved have been reclaimed since about the ruficollis) the harbour, including jet when: 1950s for industrial, port-related and Great Crested Grebe skiing which causes • population dynamics data on road projects, and further reclamation (Podiceps cristatus) disturbance to roosting the species concerned indicate remains a threat. As Cork Harbour is Cormorant birds. that it is maintaining itself on a adjacent to a major urban centre and a (Phalacrocorax long term basis as a viable major industrial centre, water quality is carbo) component of its natural variable, with the estuary of the River Grey Heron (Ardea habitats, and Lee and parts of the Inner Harbour being cinerea) • the natural range of the somewhat eutrophic. However, the Site Code Located Shelduck (Tadorna species is neither being reduced polluted conditions may not be having 004030-Cork directly tadorna) nor is likely to be reduced for significant impacts on the bird Harbour SPA within the Wigeon (Anas the populations. Oil pollution from shipping zone of penelope) foreseeable future, and in Cork Harbour is a general threat. impact Teal (Anas crecca) • there is, and will probably and the Pintail (Anas acuta) continue to be, a sufficiently 15km Shoveler (Anas large habitat to maintain its Buffer clypeata) populations on a long term Red-breasted basis. Merganser (Mergus serrator) Oystercatcher
4 http://www.npws.ie/en/PublicationsLiterature/ConservationStatusReport/ 5 http://www.npws.ie/publications/euconservationstatus/
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Natura 2000 Site Location Qualifying Interests Site Sensitivity Conservation Status, Threats5 Trend in Conservation Status4 (Haematopus ostralegus) Golden Plover (Pluvialis apricaria) Grey Plover (Pluvialis squatarola) Lapwing (Vanellus vanellus) Dunlin (Calidris alpina) Black-tailed Godwit (Limosa limosa) Bar-tailed Godwit (Limosa lapponica) Curlew (Numenius arquata) Redshank (Tringa totanus) Black-headed Gull (Chroicocephalus ridibundus) Common Gull (Larus canus) Lesser Black-backed Gull (Larus fuscus) Common Tern (Sterna hirundo) Wetlands & Waterbirds
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Table 3-6 Description of Natura 2000 Sites Screened in for further assessment
Natura 2000 Site Location Qualifying Interests1 Site Sensitivity2 Conservation Status, Trend Threats7 in Conservation Status 6 Estuaries Surface and marine water Inadequate Pollution to surface dependent. Moderately Improving (+) waters (limnic & sensitive to hydrological terrestrial, marine & change. Moderate brackish) sensitivity to pollution. nautical sports Fishing Sensitive to changes in and harvesting aquatic Site Code salinity and tidal regime as resources Within the zone of 001058- Great well as coastal estuarine and coastal impact and the 15km Island Channel development dredging Buffer SAC other outdoor sports and leisure activities bottom culture suspension culture piers / tourist harbours or recreational piers slipways Mudflats and sandflats Surface and marine water Inadequate Pollution to surface not covered by dependent. Moderately Improving (+) waters (limnic & seawater at low tide sensitive to hydrological terrestrial, marine & change. Moderate brackish) sensitivity to pollution. Fishing and harvesting Sensitive to changes in aquatic resources
salinity and tidal regime as Bottom culture well as coastal Hand collection development. Estuarine and coastal dredging Nautical sports Other outdoor sports
6 http://www.npws.ie/en/PublicationsLiterature/ConservationStatusReport/ 7 http://www.npws.ie/publications/euconservationstatus/
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Natura 2000 Site Location Qualifying Interests1 Site Sensitivity2 Conservation Status, Trend Threats7 in Conservation Status 6 and leisure activities
Spartina swards Marine water dependent. Poor (Spartinion maritimae) Medium sensitivity to hydrological changes. As Spartina is considered to be an invasive species in Ireland, it is assessed in a different way to other habitats. Increases in the
area and extent of Spartina swards are actually considered to be unfavourable and as future expansion is considered likely, the overall conservation status of this habitat is rated as poor. Atlantic salt meadows Marine and groundwater Inadequate Climate Change (Glauco-Puccinellietalia dependent. Medium Stable (=) Intensive cattle grazing maritimae) sensitivity to hydrological intensive sheep grazing change. Sensitive to paths, tracks, cycling changes in salinity and tidal tracks
regime as well as disposal of household / overgrazing, erosion and recreational facility accretion waste disposal of industrial waste
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Natura 2000 Site Location Qualifying Interests1 Site Sensitivity2 Conservation Status, Trend Threats7 in Conservation Status 6 reclamation of land from sea, estuary or marsh polderisation Modification of hydrographic functioning, general Erosion invasive non-native species
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3.2 Screening Appraisal
Based on EC (2000) and IEEM Guidelines for Ecological Impact Assessment (IEEM, 2006), impacts are listed as significant if impacts have the potential to have a significant impact on the ecological integrity on the conservation objectives (i.e. the habitats and species for which the site is designated), or on the overall integrity of the Natura 2000 site itself. The approach to assessing the significance of impacts in the IEEM guidelines (2006) states that the significance of an impact “is defined as an impact (negative or positive) on the integrity of a defined site or ecosystem and/or the conservation status of habitats or species within a given geographical area.” Definitions of ‘integrity’ and ‘conservation status’ are provided in the IEEM guidelines.
Table 3-7 Characterisation of Impacts
If an ecological feature is likely to experience a significant negative impact, the consequences of that impact will depend on the level at which the ecological feature is valued. Typically in Appropriate Assessment only features of international importance are considered as it is these features (Annex I habitats and Annex II species under the Habitats Directive and Annex I bird species under the Birds Directive) that Natura 2000 sites are designed for.
Once an impact is deemed to be significant on the basis of effects on integrity and/or conservation status, then the value of the ecological feature that will be significantly affected is used to identify the geographical scale at which the impact is significant. Impacts are not always significant at the level at which the ecological feature has been valued and may be significant at a lower geographical frame of reference. For example, a particular impact may not be considered likely to have a negative effect on the overall integrity or conservation status of a species which is considered to be internationally important. However it may be considered that there would be an impact at the local population scale
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Certain/near-Certain: probability estimated at 95% chance or higher. Probable: probability estimated 50% to 95%. Unlikely: probability estimated 5% to 50% Extremely Unlikely: probability estimated at less than 5%.
Water Quality
The proposed dredging works have the potential to impact on surface water quality through increasing the concentration of suspended sediment in the water column within the length of the channel to be dredged. Dredging works will result in increased localised concentrations of suspended solids in the water column; however the works will take place over a short time period and will have no lasting impact on water quality. For those areas in the outer estuary (which will be dredged using TSHD) the use of best practise techniques and mitigation measures will avoid any heavy accumulation of sediments in environmentally sensitive sites such as Oyster Bank and Monkstown Creek. As soon as the suction heads touch the seabed and bottom material is sucked through the suction heads and trailing pipes, the dredger operator will divert the soil mixture into the hopper by closing the pump overboard valve, thus avoiding spillage of dredged material (Van Oord Method Statement, Dec. 2011) Van Oord undertook a Water Injection Dredging Tracer Study within Cork Harbour in July 2012 to assess the environmental impact and sediment transport regime utilizing Fluorescent Particle Tracers. The study found that where Water Injection Dredging will take place in target areas within the City Quays there is a clear transport of sediment to depositional areas particularly the
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PoC Maintenance Dredging HDA Screening Statement extensive inter-tidal mudflats in Lough Mahon as well as other known or expected depositional areas such as berth pockets, creeks and shallow sub-tidal areas. The mass budget estimates for the tracer and resultant predictions for sediment thickness deposited as a result of WID at Cork City and Ringaskiddy demonstrate that the WID has dispersed the material and it has re-distributed to the wider estuarine system, but generally in the upper estuary principally in volume terms to Lough Mahon. This re-distribution up-estuary from Ringaskiddy and limited transport from Cork City area is a function of the flood-tide transport process. Although larger concentrations and higher thicknesses were detected within the Cork City area, it is unlikely to remain there in totality due to scouring as a result of spring tides, increased seasonal river flow and vessel activity, the tracer results unequivocally confirm the clear tidally dominated process and deposition that takes place. If the sampling surveys had covered a wider area and/or over a longer time period it is possible that these estimated deposits would have decreased as further transport and deposition takes place. The results tend to show that WID dredging could lead to a more rapid return of sediment to Cork City area leading to navigable depth decreases; however, this is a natural process. Other than disposal at sea or more controlled beneficial use as has been demonstrated successfully in other similar locations (Medway estuary), which in turn removes the material from the local sediment regime, WID does offer a very effective way of dispersing a large proportion of the maintenance dredge material to an area which does not impinge on port operations as significantly and is beneficial for habitat conservation, namely Lough Mahon.
The results do show that tracer particles and therefore dredged silt sediment did deposit and remain within the environmentally sensitive sites such as Oyster Bank and Monkstown Creek. However, the data clearly show that this deposition is spread quite well with no concentrated accumulations of sediment that would be harmful to the shellfishery and marine flora and fauna at these sites. Furthermore, it is likely given the location of Oyster Bank in particular, that these sites are directly and/or indirectly affected by storms and short-term sedimentation changes as a result. Overall this impact is not considered long term or permanent in nature and will not lead to a loss of site integrity to either the surrounding SACs or SPAs.
The mobilisation of contaminants within the trigger areas where WID will be undertaken is not expected at concentrations likely to cause significant or long term impacts given that most are at typical or expected background levels within the sediment for an industrial port such as the Port of Cork.
There is also potential for oil or fuel spills during the operation of the dredging machinery. Although a spill event is extremely unlikely (i.e. probability estimated at less than 5%), should an accidental spill occur it could have significant negative impacts on water quality and therefore indirectly on fauna species for which this SAC is designated. This could have an indirect impact on the fauna species listed below.
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Water Quality Impact Prediction: No significant impact from sediment disturbance
Disturbance to Habitat
The key qualifying interest habitats which will be directly impacted on is Estuaries [1130], Mudflats and sandflats not covered by seawater at low tide [1140] The proposed activity (Maintenance dredging) will not take place within these habitat types. The impact will not result in the loss of this habitat but will result in disturbance to it, as well as its benthic fauna communities. This habitat is already highly modified through the tidal regime in the area and the processes of erosion, accretion and deposition which act on those habitats. Additionally having been subject to regular maintenance and to a lesser extent capital dredging for many years a certain level of change also occurs.
Benthic faunal surveys were carried out by Aquatic Services Unit within the dredging area in 2011- 2012 to co-inside with pre and post dredging works. The study comprised a main baseline and a main follow-up survey covering all sampling methods in all survey areas in May/June 2011 i.e. pre-dredging and again in May/June 2012 about 5-9 months post-dredging. A quarterly survey was undertaken in late February/early March 2-6 months post dredging involving a reduced sampling intensity.
The survey concentrated on 4 main areas and a control site in the North Channel at Rossmore.
Area 1 was between the City Quays and Marina Power Station, Area 2 stretched from the Marina Power Station as Blackrock Castle; Area 3 stretched from Blackrock Castle to approximately half way down Lough Mahon, while Area 4 continued to the end of Lough Mahon to the bend opposite Marino Point. Sampling included intertidal core sampling and sub-tidal grab sampling within the study areas.
Benthic Survey – Methods and Results
Intertidal Macrobenthic Sampling
4 intertidal transects were studied, T1-T3 in the greater Lough Mahon area (T1 by Hop Island, T2 by Carrigrenan, T3 inside Marino and T4 the control site in the North Channel at Rossmore).
At each site, replicate stove-pipe cores were taken at three tidal heights High Shore, Mid-Shore and Low Shore.
Pre-dredging sampling took place in May 2011, and post-dredging took place in February 2012 and June 2012.
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The results indicate that there was a pronounced difference between the numbers and biomass of macroinvertebrate infauna between the four transects with T1 and T4 having higher numbers and biomass on all sampling occasions than T2 and T3.
There was also a pronounced difference between the numbers and biomass of invertebrates between shore heights at all transects with the low shore almost always having considerably lower abundances and biomass than the mid or high shore stations and the high shore sites tending to have the highest numbers and biomass at all transects during all three sampling occasions. 4
During February 2012, some 2-3 months after the cessation of maintenance dredging in the shipping channel there was a pronounced drop in both faunal numbers and biomass at all transects including the control site (T4). Because this decrease was so clear across all sites including the control and at all tidal heights it was considered to be a normal seasonal trend. Such seasonal drops in biomass and numbers are widely reported in the scientific literature.
During the June follow up survey, some 5-7 months after the cessation of maintenance dredging, macroinvertebrate populations from the February, saw a significant increase across all transects, again this would be expected as a normal seasonal trend on intertidal mudflats. The results varied between transects and between shore heights, so for instance at T1 the biomass at the high and low shore stations increased to the levels recorded in the May 2011 baseline survey, while the mid-shore sites remained as low as during February 2012. At T2, biomass remained the same or increased at all tidal heights compared to the May 2011 baseline and at T3 the low shore biomass did not increase above the levels recorded in February, whereas at the mid-shore and high shore stations they did. Finally at the control site T4 in Rossmore, while stations at all three shore heights increased in biomass compared to the February seasonal low, only the low shore site reached (and exceeded) the values recorded during the May 2011 baseline. This latter result is attributed to fine-scale patchiness in the distribution of benthic invertebrates.
Finally, when all of the data from all three sampling runs is pooled and analysed using a multivariate analysis technique – MDS (Multi Dimensional Scaling), all the data points (transects, tidal heights and sampling occasions) pool together into a single cluster, which indicates that we are dealing with a single intertidal faunal community typical of sandy mud conditions.
The inter-transect, inter shore height and between sampling run variation noted within the data is concluded to fall within normal temporal and spatial variability ranges typical of such communities with little if any influence from the maintenance dredging operations in the shipping channel.
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Subtidal Benthic Infauna
Subtidal benthic grabs were taken in four sampling areas (Area 1 to 4) during the study and at three stations across the channel within each of these four locations.
Sampling for benthic infauna was carried out on three occasions, namely May 2011 before maintenance dredging of the channel and in February 2012 and June 2012 after the dredging had taken place.
Recovery of faunal communities in dredged sediments is led by opportunistic species such as small polychaetes colonising sediments rapidly after the cessation of the dredging. These eventually give way to the recovery also of what are referred to as equilibrium species1. Once a community has regained 80% of its diversity and biomass compared to pre-dredging levels, it is considered to have fully recovered (Newell et al., 1998). The same author points to recovery rates in estuarine, muddy sediment varying from 6-12 months post cessation of dredging.
Dredging within the survey area commenced in August 2011 and completed in January 2012. Areas between the City Quays to Marino Point were subjected to maintenance dredging between late August 2011 and January 2012. Water injection dredging occurred in Area’s 1 & 2 whilst trailer suction hopper dredging occurred in Area’s 2, 3 & 4.
Results from the sub-tidal survey indicate significant changes in biomass, abundances and diversity in Areas 1, 2 & 3 from pre-dredge levels in 2011 to post dredge levels in 2012. However, faunal communities identified in the area are consistent with recovering communities as they are dominated by opportunistic species with a smaller representation of equilibrium species in each of these areas. Although biomass levels are much reduced compared to pre-dredge levels, this is not unexpected as dredging had only stopped in the areas 5 months previously. This timescale is consistent with previous studies on the recovery of sub-tidal dredged sediments in estuarine conditions (Bonsdorff, 1980; Newell et al., 1998)
The results indicate that while changes do occur in the benthic fauna community structure after dredging it is likely to be medium term and locally significant, as it will cause the temporary removal of all communities present within the area of the proposed dredging works. The benthic community removed or damaged during the operation should begin to re-establish itself almost immediately after the cessation of the works and recover in the short to medium term as is indicated through the results of the ASU study outlined above.
Habitat Disturbance Impact Prediction: Medium term locally significant impact
Fisheries
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Aquatic Services Unit also carried out a fisheries assessment pre and post dredging works between 2011 and 2012 on behalf of the Port of Cork. The fisheries aspect of the study was intended to assess any before or after impacts from the proposed dredging and to gather baseline information on the fish community present and across the study area from the City Quays to Lower Lough Mahon and what it was feeding on. A range of survey methods were employed including baited pots, fykes nets and trawls, seine nets, with most effort employed in the first 3 methods. The fisheries surveys undertaken in 2011 and 2012 indicate that the study area within Cork Harbour has a typical estuarine fish community which is dominated by a mixture of more estuarine dependent species and marine species which enter estuaries for either feeding or predator avoidance or both. The surveys also demonstrate the importance of the two mobile epibenthic crustaceans green crab and Crangon (brown shrimp) throughout the study areas. Overall it was found that the community structure has remained largely the same after the dredging and in this respect the impact of the dredging is not thought to have been significant.
Fisheries Impact Prediction: No significant impact
Disturbance to birds
Within the vicinity of Monkstown and Ringaskiddy this part of Cork Harbour supports a breeding population of the Birds Directive Annex I species Common Tern. Breeding Common Tern is a Qualifying Interest of Cork Harbour SPA (site code 004030). Historically, Common Terns have nested at a variety of locations in the western part of the harbour; in 2011 they nested in three separate locations, at the Deep Water Port in Ringaskiddy; on the Martello Tower adjacent to the railway line immediately south of Fota Island and on the island in the lake at Pfizer’s Golf Course at Shanbally (see Figure 3-3)
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Figure 3-3 Common Tern nesting locations, 2011 (Source: Breeding Bird Surveys, 2011 RPS)
Common Tern is the only Qualifying Interest of Cork Harbour SPA that relates to a breeding bird species, the other Qualifying Interests are all non-breeding ‘wintering’ bird populations which are present in the harbour primarily during the winter period and / or the spring and autumn migration periods. A number of these ‘wintering’ species are however also present in the area in substantial numbers during the summer breeding season; and larger numbers of some species arrive during July and August, at the commencement of the autumn migration period.
Little Grebe, Grey Heron and Shelduck, which are included as Qualifying Interests of the SPA for their non-breeding populations, breed in small numbers within Cork Harbour, and some records of Shelduck and Grey Heron presented in the 2011 report refer to birds from these breeding populations. Such breeding populations should be considered part of the ‘Wetlands’ Qualifying Interest of the SPA.
The breeding terns located within the Ringaskiddy Deep Water Port are subject to extraordinarily high levels of man-made noise and visual disturbance to which they appear to be entirely habituated. Loud irregular noise from human sources and movement of machinery, vehicles and people close-by is a near-constant feature of the site. Sources include road traffic within 100m, including a high proportion of trucks and other large commercial vehicles many of which are stopping and starting, revving engines and using air brakes; port activity including mass bulk handling within 200m; pedestrians and regular human voices within 100m (for example at the Deep Water Port security desk) and the regular
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The only population of relevance to the maintenance dredging works is the population at the Deep Water Port at Ringaskiddy. The others are not within close proximity of any dredging works and are outside the direct or in-direct zone of influence. Given that the Common Tern population within the Deep Water Port at Ringaskiddy currently tolerate a high volume of shipping through the area and the SPA in general and as outlined above have become habituated to high levels of man-made sound, it is considered highly unlikely that the maintenance dredging works which will be required every third, will have any significant impact on common tern populations for which the SPA is designated. The key potential impact relates to disturbance to feeding areas for which one key area to the front of the Ringaskiddy basin will be affected. This effect will represent a short term disturbance and will not lead to the permanent displacement of the qualifying feature with a number of alternative feeding areas available in close proximity which can be utilised for the duration of the dredging works.
A number of other qualifying interest features of the SPA also utilise the inter-tidal mudflats surrounding the Ringaskiddy Deep Water Port including; Cormorant, Grey Heron, Shelduck, Lapwing, Dunlin, Black-Tailed Godwit, Curlew, Redshank, Oystercatcher and Teal. These species move between high and low tide feeding areas within the wider Ringaskiddy area and are not restricted to a set number of suitable feeding areas. As with the Common Tern these species have also become habituated to vessel movements and therefore will not be permanently displaced or affected by the dredging works. As no dredging works will take place at low tide, any disturbance will relate to high tide feeding which will be limited and short lived.
Disturbance to Birds Impact Prediction: No significant impact, potential for short term disturbance to high tide feeding which will not represent a permanent effect.
3.2.1 Brief Description of the Other Plans/Projects Which Could Give Rise to In-combination Effects The Port of Cork have begun preliminary environmental assessments in relation to the potential development works at Ringaskiddy, Co. Cork. Details are preliminary to allow commencement of the environmental assessments and some elements may be subject to change as the design and assessments develop. At this stage in the development it is difficult to ascertain the potential in-combination effects due to the lack of detailed design and outputs from the preliminary environmental assessments. It may be some years before the assessments and the detailed design are complete however at that stage a full EIA and associated Natura Impact Report will be prepared which will take into consideration any future maintenance dredging works in conjunction with the Ringaskiddy project and undertake a complete assessment at that stage.
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In order to avoid and reduce impacts on water quality the following procedures and methodologies are proposed as part of the dredging campaign and associated dumping at sea process:
A good dredging regime prepared with due regard to recognised guidance notes for same will be employed in order to minimise the release of suspended particulate matter within the water column. With regard to potential oil spills during dredging operations, an emergency spill kit and oil spill containment equipment will be held on board by the dredging operator. The Port of Cork has in place an Oil Spill Contingency Plan which is adhered to by all staff including those employed to carry out maintenance dredging on behalf of the Port. This plan is provided to assist the Harbour Master, or in his absence the Deputy Harbour Master of the Port of Cork Company in dealing with an accidental discharge of oil and/or HNS. Its primary purpose is to set in motion the necessary actions to stop or minimise the discharge and to mitigate its effects. Effective planning ensures that the necessary actions are taken in a structured, logical and timely manner. This plan (Oil Spill /HNS Plan) guides Port of Cork staff (and other related organisations who hold a copy of the plan) through the various actions and decisions which will be required in an incident response. The Port of Cork will carry sediment analysis every 3 years a few months prior to each dredging campaign. In line with recommendations of the ASU Assessment of Benthic and Fisheries Impacts of the Maintenance Dredging in Lough Mahon and the Lower River Lee a June trawl sample should be taken in Areas 3 & 4 each year and a record maintained of the species encountered and their relative abundance. This data can be used to give context to any future before/after surveys of dredging activity. A daily log will be maintained of the dredging and dumping locations and times.
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Table 3-8 Assessment of Residual Impacts Site Name and Qualifying Interests Potential Impacts Potential Cumulative Proposed Mitigation Residual Impacts Code Impacts
Special Protection Area (Cork Harbour SPA) & Special Area of Conservation (Great Channel Island SAC)
Little Grebe Disturbance during These species move No significant None anticipated (Tachybaptus ruficollis) feeding. between high and low impacts tide feeding areas within the wider Ringaskiddy Great Crested Grebe area and are not No significant (Podiceps cristatus) impacts restricted to a set number of suitable Cormorant feeding areas. As with No significant
(Phalacrocorax carbo) the Common Tern they impacts have also become habituated to vessel Grey Heron (Ardea movements and No significant cinerea) therefore will not be impacts permanently displaced Shelduck (Tadorna or affected by the No significant tadorna) dredging works. As no impacts dredging works will take place at low tide, any Wigeon (Anas disturbance will relate to No significant penelope) high tide feeding which impacts will be limited and short
lived. Teal (Anas crecca) No significant impacts
Pintail (Anas acuta) No significant impacts
Site Code 004030- Shoveler (Anas No significant
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Cork Harbour SPA clypeata) impacts
Red-breasted No significant Merganser (Mergus impacts serrator)
Oystercatcher No significant (Haematopus impacts ostralegus)
Golden Plover (Pluvialis No significant apricaria) impacts
Grey Plover (Pluvialis No significant squatarola) impacts
Lapwing (Vanellus No significant vanellus) impacts
Dunlin (Calidris alpina) No significant impacts
Black-tailed Godwit No significant (Limosa limosa) impacts
Bar-tailed Godwit No significant (Limosa lapponica) impacts
Curlew (Numenius No significant arquata) impacts
Redshank (Tringa No significant
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totanus) impacts
Black-headed Gull No significant (Chroicocephalus impacts ridibundus)
Common Gull (Larus No significant canus) impacts
Lesser Black-backed No significant Gull (Larus fuscus) impacts
Common Tern (Sterna Disturbance to None anticipated This effect will represent No significant hirundo) common tern a short term disturbance impacts population at Deep and will not lead to the Water Quay permanent displacement Ringaskiddy of the qualifying feature with a number of alternative feeding areas available in close proximity which can be utilised for the duration of the dredging works.
Wetlands & Waterbirds None None None required No significant impacts
Estuaries The impact will not None anticipated While changes will occur No significant result in the loss of impacts in the benthic fauna this habitat but will Site Code 001058- result in disturbance community structure Great Island Mudflats and sandflats to it as well as its None anticipated No significant after dredging it is likely Channel SAC not covered by benthic fauna impacts seawater at low tide communities. to be medium term and
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locally significant, as it will cause the temporary removal of all communities present within the area of the proposed dredging works. The benthic community removed or damaged during the operation should begin to re-establish itself almost immediately after the cessation of the works and recover in the short to medium term.
The dredging regime will employ measures to minimise the release of suspended particulate matter within the water column.
Spartina swards None anticipated None anticipated None anticipated No significant (Spartinion maritimae) impacts
Atlantic salt meadows None anticipated None anticipated None anticipated No significant (Glauco-Puccinellietalia impacts maritimae)
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3.2.2 Conclusions of assessment process
As confirmed in the checklist in Table 3-9 below, all of the potential impacts identified will be avoided with the correct implementation of the proposed mitigation measures. As there are no significant residual negative impacts on any of the conservation objectives of any Natura 2000 sites, it is concluded that the proposals (Maintenance Dredging) will not have a significant negative impact on any Natura 2000 site located surrounding the dredging works within the Port of Cork.
Table 3-9 Integrity of the site in Relation to Residual Impacts Table 3-9 Integrity of the site in Relation to Residual Impacts
Does the project have the potential to: Yes Details or No Cause delays in progress towards achieving the conservation No No significant residual objectives of the site? negative impacts Interrupt progress towards achieving the conservation objectives of No No significant residual the site? negative impacts Disrupt those factors that help to maintain the favourable conditions No No significant residual of the site? negative impacts Interfere with the balance, distribution and density of key species No No significant residual that are the indicators of the favourable condition of the site? negative impacts Cause changes to the vital defining aspects (e.g. nutrient balance) No No significant residual that determine how the site functions as a negative impacts Change the dynamics of the relationships (between, for example, No No significant residual water with flora and fauna) that define the structure and/or function negative impacts of the site? Interfere with predicted or expected natural changes to the site No No significant residual (such as water dynamics or chemical composition)? negative impacts Reduce the area of the key habitats? No No significant residual negative impacts Reduce the population of the key species? No No significant residual negative impacts Change the balance between key species? No No significant residual negative impacts Reduce diversity of the site? No No significant residual negative impacts Result in disturbance that could affect population size or density or No No significant residual the balance between key species? negative impacts Result in habitat fragmentation? No No significant residual negative impacts Result in loss or reduction of key features (e.g. inter-tidal/tidal No No significant residual feeding areas, alteration to tidal regime, etc.) negative impacts
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Due to the location of the proposed dredging activities outside of any Natura 2000 sites but in close proximity to the Cork Harbour SPA and the Great Channel Island SAC it was necessary to undertake a Habitats Directive Assessment Screening Assessment.
Following a review of the Dump Site in relation to its proximity to any Natura 2000 site for this screening assessment and the undertaking of an impact hypothesis by Irish Hydrodata Ltd (IHD) on behalf of the Port of Cork this element of the overall project (Potential impact from the disposal of dredge spoil at the dump site) was screened out from any further assessment.
As a result of the appropriate design of the proposed activities (Maintenance Dredging) and the proposed mitigation measures which form part of the overall project design, this report concludes that the proposed development will have no significant residual impacts on the integrity of the two Natura 2000 sites (initially screened in) and within close proximity to the proposed maintenance dredging locations.
Following the implementation of the procedures outlined under Section 3.2.1 and adherence to the procedures contained and discussed in the ESPO Checklist in Appendix B, it is expected that the proposed maintenance dredging works will avoid any significant (and permanent) negative impacts to key sensitive receptors and qualifying features of the SAC and SPA both along and in-combination with the other elements identified in this report.
This assessment has therefore stopped at Stage 1 Screening and there should be no further requirement for Stage 2 Appropriate Assessment, Stage 3 (Assessment of Alternative Solutions) or Stage 4 (Assessment Where Adverse Impacts Remain) of the appropriate assessment process.
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4.0 REFERENCES
Analysis of Cork Harbour Sediments-Amendment Report, Enterprise Ireland, 2013
Assessment of Benthic and Fisheries Impact of Maintenance Dredging in Lough Mahon and the Lower River Lee, Aquatic Services Unit, Port of Cork, 2011-2012
Breeding Season Bird Survey at Ringaskiddy, Port of Cork Bird Surveys Report, 2012 (Internal report on behalf of the Port of Cork)
Cork Dredge Spoil Disposal Site, Impact Hypothesis Update, Irish Hydrodata Limited, 2013
Cork Harbour Pin Survey, Van Oord, Aquatic Services Unit, December 2011(Internal report on behalf of the Port of Cork)
Cork Harbour Sediment Pin Survey, Appendix B, Van Oord, Aquatic Services Unit, December 2011
Dredging Management plan, Port of Cork, 2008-2012 (Volumes 1 - 2)
Environmental aspects of Cork harbour dredging, Van Oord, May 2012 (Internal report on behalf of the Port of Cork)
Environmental Impact and Sediment Transport Study Utilising Fluorescent Particle Tracers, Water Injection Dredging Tracer Study-Cork, Appendix A, Van Oord, Final Report, July 2012
Integrated Report on Environmental Aspects of Cork Harbour Dredging, Port of Cork, July 2013
Night-roosting Cormorants at Monkstown Creek, Cork Harbour, 2012 (Internal report on behalf of the Port of Cork)
Re-analysis and Re-sampling of Sediment Samples at five sites in the Port of Cork on Behalf of the Port of Cork Company, Aquatic Services Unit, January 2014
Van Oord Method Statement Dredging (TSHD) December 2011
Winter 2011/2012 Bird Survey at Ringaskiddy/ Monkstown Creek, Port of Cork, 2012 (Internal report on behalf of the Port of Cork)
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APPENDIX A
NATURA 2000 SITE SYNOPSIS
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SITE NAME: CORK HARBOUR SPA
SITE CODE: 004030
Cork Harbour is a large, sheltered bay system, with several river estuaries - principally those of the Rivers Lee, Douglas, Owenboy and Owennacurra. The SPA site comprises most of the main intertidal areas of Cork Harbour, including all of the North Channel, the Douglas River Estuary, inner Lough Mahon, Monkstown Creek, Lough Beg, the Owenboy River Estuary, Whitegate Bay and the Rostellan and Poulnabibe inlets.
Owing to the sheltered conditions, the intertidal flats are often muddy in character. These muds support a range of macro-invertebrates, notably Macoma balthica, Scrobicularia plana, Hydrobia ulvae, Nepthys hombergi, Nereis diversicolor and Corophium volutator. Green algae species occur on the flats, especially Ulva lactua and Enteromorpha spp. Cordgrass (Spartina spp.) has colonised the intertidal flats in places, especially where good shelter exists, such as at Rossleague and Belvelly in the North Channel. Salt marshes are scattered through the site and these provide high tide roosts for the birds. Salt marsh species present include Sea Purslane (Halimione portulacoides), Sea Aster (Aster tripolium), Thrift (Armeria maritima), Common Saltmarsh-grass (Puccinellia maritima), Sea Plantain (Plantago maritima), Lax- flowered Sea-lavender (Limonium humile) and Sea Arrowgrass (Triglochin maritima). Some shallow bay water is included in the site. Cork Harbour is adjacent to a major urban centre and a major industrial centre. Rostellan Lake is a small brackish lake that is used by swans throughout the winter. The site also includes some marginal wet grassland areas used by feeding and roosting birds.
The site is a Special Protection Area (SPA) under the E.U. Birds Directive, of special conservation interest for the following species: Little Grebe, Great Crested Grebe, Cormorant, Grey Heron, Shelduck, Wigeon, Teal, Pintail, Shoveler, Red-breasted Merganser, Oystercatcher, Golden Plover, Grey Plover, Lapwing, Dunlin, Black- tailed Godwit, Bar-tailed Godwit, Curlew, Redshank, Black-headed Gull, Common Gull, Lesser Black-backed Gull and Common Tern. The site is also of special conservation interest for holding an assemblage of over 20,000 wintering waterbirds. The E.U. Birds Directive pays particular attention to wetlands and, as these form part of this SPA, the site and its associated waterbirds are of special conservation interest for Wetland & Waterbirds.
Cork Harbour is an internationally important wetland site, regularly supporting in excess of 20,000 wintering waterfowl, for which it is amongst the top five sites in the country. The two-year mean of summed annual peaks for the entire harbour complex was 55,401 for the period 1995/96 and 1996/97. Of particular note is that the site supports internationally important populations of Black-tailed Godwit (905) and Redshank (1,782) - all figures given are average winter means for the two winters 1995/96 and 1996/97. At least 18 other species have populations of national importance, as follows: Little Grebe (51), Great Crested Grebe (204), Cormorant (705), Grey Heron (63), Shelduck (2,093), Wigeon (1,852), Teal (922), Pintail (66), Shoveler (57), Red-breasted Merganser (88), Oystercatcher (1,404), Golden Plover (3,653), Grey Plover (84), Lapwing (7,688), Dunlin (10,373), Bar- tailed Godwit (417), Curlew (1,325) and Greenshank (26). The Shelduck population is the largest in the country (over 10% of national total). The site has regionally or locally important populations of a range of other species, including Whooper Swan (10), Pochard (145) and Turnstone (79). Other species using the site include Gadwall (13), Mallard (456), Tufted Duck (113), Goldeneye (31), Coot (53), Mute Swan (38), Ringed Plover (34) and Knot (38). Cork Harbour is a nationally important site for gulls in winter and autumn, especially Black-headed Gull (4,704), Common Gull (3,180) and Lesser Black-backed Gull (1,440).
A range of passage waders occurs regularly in autumn, including such species as Ruff (5-10), Spotted Redshank (1-5) and Green Sandpiper (1-5). Numbers vary between years and usually a few of each of these species over-winter.
The wintering birds in Cork Harbour have been monitored since the 1970s and are counted annually as part of the I-WeBS scheme.
Cork Harbour has a nationally important breeding colony of Common Tern (3-year mean of 69 pairs for the period 1998-2000, with a maximum of 102 pairs in 1995). The birds have nested in Cork Harbour since about 1970, and since 1983 on various artificial structures, notably derelict steel barges and the roof of a Martello Tower. The birds are monitored annually and the chicks are ringed.
Extensive areas of estuarine habitat have been reclaimed since about the 1950s for industrial, port-related and road projects, and further reclamation remains a threat. As Cork Harbour is adjacent to a major urban centre and a major industrial centre, water quality is variable, with the estuary of the River Lee and parts of the Inner Harbour being somewhat eutrophic. However, the polluted conditions may not be having significant impacts on the bird populations. Oil pollution from shipping in Cork Harbour is a general threat. Recreational activities are high in some areas of the harbour, including jet skiing which causes disturbance to roosting birds.
Cork Harbour is of major ornithological significance, being of international importance both for the total numbers of wintering birds (i.e. > 20,000) and also for its populations of Black-tailed Godwit and Redshank. In addition, there are at least 18 wintering species that have populations of national importance, as well as a nationally important breeding colony of Common Tern. Several of the species which occur regularly are listed on Annex I of the E.U. Birds Directive, i.e. Whooper Swan, Golden Plover, Bar-tailed Godwit, Ruff and Common Tern. The site provides both feeding and roosting sites for the various bird species that use it.
26.2.2008 SITE SYNOPSIS
SITE NAME: GREAT ISLAND CHANNEL
SITE CODE: 001058
The Great Island Channel stretches from Little Island to Midleton, with its southern boundary being formed by Great Island. It is an integral part of Cork Harbour which contains several other sites of conservation interest. Geologically, Cork Harbour consists of two large areas of open water in a limestone basin, separated from each other and the open sea by ridges of Old Red Sandstone. Within this system, Great Island Channel forms the eastern stretch of the river basin and, compared to the rest of Cork Harbour, is relatively undisturbed. Within the site is the estuary of the Owennacurra and Dungourney Rivers. These rivers, which flow through Midleton, provide the main source of freshwater to the North Channel.
The main habitats of conservation interest are the sheltered tidal sand and mudflats and Atlantic salt meadows, both habitats listed on Annex I of the EU Habitats Directive. Owing to the sheltered conditions, the intertidal flats are composed mainly of soft muds. These muds support a range of macro-invertebrates, notably Macoma balthica , Scrobicularia plana , Hydrobia ulvae , Nepthys hombergi, Nereis diversicolor and Corophium volutator . Green algal species occur on the flats, especially Ulva lactua and Enteromorpha spp. Cordgrass ( Spartina spp.) has colonised the intertidal flats in places, especially at Rossleague and Belvelly. The salt marshes are scattered through the site and are all of the estuarine type on mud substrate. Species present include Sea Purslane ( Halimione portulacoides ), Sea Aster ( Aster tripolium ), Thrift ( Armeria maritima ), Common Saltmarsh-grass (Puccinellia maritima ), Sea Plantain ( Plantago maritima ), Greater Sea-spurry (Spergularia media), Sea Lavender ( Limonium humile ), Sea Arrowgrass ( Triglochin maritimum ), Mayweed ( Matricaria maritima ) and Red Fescue ( Festuca rubra ).
The site is extremely important for wintering waterfowl and is considered to contain three of the top five areas within Cork Harbour, namely North Channel, Harper's Island and Belvelly-Marino Point. Shelduck are the most frequent duck species with 800-1000 birds centred on the Fota/Marino Point area. There are also large flocks of Teal and Wigeon, especially at the eastern end. Waders occur in the greatest density north of Rosslare, with Dunlin, Godwit, Curlew and Golden Plover the commonest species. A population of about 80 Grey Plover is a notable feature of the area. All the mudflats support feeding birds; the main roost sites are at Weir Island and Brown Island and to the north of Fota at Killacloyne and Harper’s Island. Ahanesk supports a roost also but is subject to disturbance. The numbers of Grey Plover and Shelduck, as given above, are of national importance.
The site is an integral part of Cork Harbour which is a wetland of international importance for the birds it supports. Overall, Cork Harbour regularly holds over 20,000 waterfowl and contains Internationally important numbers of Black-tailed Godwit (1,181) and Redshank (1,896) along with Nationally important numbers of nineteen other species. Furthermore, it contains the large Dunlin (12,019) and Lapwing (12,528) flocks. All counts are average peaks, 1994/95 – 1996/97. Much of the site forms part of Cork Harbour Special Protection Area, an important bird area designated under the EU Birds Directive.
While the main land use within the site is aquaculture (Oyster farming), the greatest threats to its conservation significance come from road works, infilling, sewage outflows and possible marina developments.
The site is of major importance for the two habitats listed on the EU Habitats Directive that it contains, as well as for its important numbers of wintering waders and wildfowl. It also supports a good invertebrate fauna.
2.10.2001
APPENDIX B
ESPO Checklist
IBE0867.00 AP B Rev V03
ESPO checklist on good practise for balancing Natura 2000 with port and waterway development and operations (December 2009). (Source; EC Guidance on the implementation of the EU nature legislation in estuaries and coastal zones) 8
Maintenance Dredging
Checklist Item Action under Port of Cork Maintenance Dumping at Sea Application
A maintenance dredging strategy has been set up PoC have undertaken extensive independent taking into account hydro-morphological and ecological and biological assessments. Sediment ecological aspects. analysis and investigated the use of alternative methods of dredging to ensure the least possible impact on the receiving environment.
Based on latest information and a feedback- By carrying out this Appropriate Assessment PoC process involving all relevant stakeholders, are aiming to achieve the least impact on Natura dredging activities are – in compliance with 2000 conservation objectives through the economical and legal requirements – aiming to identification of all appropriate mitigation achieve the least impact on Natura 2000 measures. conservation objectives possible.
A sustainable maintenance dredging strategy or PoC will be bound by the conditions set upon scheme is part of an integral management plan. them by the EPA in their dumping at sea permit. Based on general principles in compliance with This will ensure a sustainable maintenance conservation objectives, dredging is flexible dredging strategy is adopted. The EPA will according to the requirements of a dynamic tidally consult with all statutory parties including the influenced estuarine, river or coastal system. NPWS and IFI prior to consent and therefore this will ensure the general principles are in compliance with conservation objectives.
Dredging activities have been optimized PoC will ensure dredging operations are according to the following order: optimized in line with the ESPO checklist provided here. The Port Company has been - Technical feasibility proactive in investigating the use of alternative methods of dredging within the Port of Cork and - Least environmental impact primarily the inner port where trigger areas will be dredged using Water Injection Dredging. WID is a
8 http://ec.europa.eu/environment/nature/natura2000/management/docs/guidance_doc.pdf
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relatively flexible method of dredging in confined - Availability of dredgers areas such as harbours, marinas and around
- Safety, nautical requirements, navigability berths and pontoons due to the small size of the dredging plant. It is considered to be beneficial to - Legally binding ecological requirements sediment management in a given area since the (BHD, WFD etc.) sediment is retained within the local system rather than taken out of that system and disposed of at - Administrative regulations (e.g. management sea. plans, site specific objectives)
- Full integration of long-term comprehensive hydro morphologic, sediment related and ecological criteria
- Short-term and/or local criteria
- Cost-effectiveness
- Other non-binding aspects such as agreements with stakeholders
Natura 2000 site management and maintenance measures
The aim should be to meet feasible conservation POC by undertaking this Habitats Directive objectives for sites in balance with long term ports Assessment aim to meet the conservation and waterways development. objectives of the sites in which their ports are located in order to work in harmony with the designations and their qualifying interest features
Port and waterways authorities should be actively The PoC maintain an Environmental involved in the setting up of management plans Management Systems compliant with from the start. European Sea Ports Organisation ECOPORTS criteria and are certified to ISO 14001.
Through the operation of best practice the principle of “pollution prevention” is applied to emission management, waste minimisation, efficient resource use and conservation awareness.
The Port is also committed to the
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application of relevant environmental legislation, regulations and industry codes of practice. The Port undertake continual environmental performance improvement, by achieving realistic objectives and targets in the context of a systematic management programme They communicate and implement this environmental policy statement with all employees and providing appropriate training They make this environmental policy statement available to our stakeholders and the general public, and supporting local community liaison Provide public reporting on environmental performance Ensure the availability of necessary resources to implement this policy
In dealing with uncertainties (ecosystem As part of this HDA key mitigation measures have knowledge, cause-effect relationships), research been identified to ensure uncertainties in terms of and monitoring schemes should be included as impacts to qualifying interests are monitored part of the management plan. during the course of the dredging operations.
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