SECTION F – EXISTING ENVIRONMENT & IMPACT OF THE DISCHARGE(S)

Attachment F1: Assessment of Impact on Receiving Surface or Ground Water

− Attachment F.1(a): An Assessment of the Impacts of Any Existing or Proposed Emissions on the Environment

Irish Water Report

Appropriate Assessment Screening and NIS as part of the Gweesalia Waste Water Discharge Certificate of Authorisation Application

Contents

Introduction 4 Legislative Context 4

Methodology 6 Guidance Followed 6 Stages Involved in the Appropriate Assessment Process 7 Stage 1: Screening / Test of Significance 8

Screening 9 Description of the Project 9 Description of the Receiving Environment and Monitoring Results 10 Brief Description of the Natura 2000 Sites 11 Potential Impacts of the Existing Discharge and Likely Significant Effects on Natura 2000 Sites 15 Direct, Indirect or Secondary Impacts 15 Possible Cumulative Impacts with other Plans and Projects in the Area 16 Summary of Potential Impacts and Likely Significant Effects 16 Likely Changes to the Natura 2000 Site(s) 19 Elements of the Project where the Impacts are Likely to be SignificantError! Bookmark not defined.

Screening Conclusion 20

Stage 2: Appropriate Assessment 21 Description of the Natura 2000 Site Affected 21 Mullet/Blacksod Bay Complex SAC 21 Description of the Conservation Interests of the SAC 21 Annex I Habitats 21 Annex II Species 22 Blacksod Bay/ Broad Haven SPA 25 Impact Prediction 29 Impacts on Water Quality 29 Impacts on Annex I Habitats 30 Impacts on Annex II Species 31 Impacts on Special Conservation Interests of the SPA 32 Mitigation Measures 32

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Stage 2 Appropriate Assessment Conclusion Statement 33

References 33

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Introduction

This report provides an Appropriate Assessment (AA) Screening and NIS of the existing Wastewater Treatment Plant (WwTP) at Gweesalia, Co. Mayo, for the purposes of the Waste Water Discharge (Authorisation) Regulations, 2007 (S.I. No. 684 of 2007), as amended. It assesses whether the ongoing operation of the plant, alone or in combination with other plans and projects, is likely to have significant effects on a Natura 2000 Site(s) in view of best scientific knowledge and the conservation objectives of the site(s). Natura 2000 Sites are those identified as sites of European Community importance designated as Special Areas of Conservation under the Habitats Directive or as Special Protection Areas under the Birds Directive.

This report follows the guidance for AA published by the Environmental Protection Agency’s (EPA) ‘Note on Appropriate Assessments for the purposes of the Waste Water Discharge (Authorisation) Regulations, 2007 (S.I. No. 684 of 2007)’ (EPA, 2009); and takes account of the Department of the Environment, Heritage and Local Government’s guidelines ‘Appropriate Assessment of Plans and Projects in Ireland. Guidance for Planning Authorities’ (DoEHLG, 2009) and Circular L8/08 ‘Water Services Investment and Rural Water Programmes – Protection of Natural Heritage and National Monuments’ (DoEHLG, 2008).

This Appropriate Assessment was carried out by a qualified ecologist working for Irish Water.

Legislative Context The Council Directive 92/43/EEC on the Conservation of Natural Habitats and of Wild Fauna and Flora, better known as “The Habitats Directive”, provides legal protection for 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. These are Special Areas of Conservation (SACs) designated under the Habitats Directive and Special Protection Areas (SPAs) designated under the Conservation of Wild Birds Directive (79/409/ECC) as codified by Directive 2009/147/EC.

Articles 6(3) and 6(4) of the Habitats Directive set out the decision-making tests for plans and projects likely to affect Natura 2000 sites (Annex 1.1). Article 6(3) establishes the requirement for Appropriate Assessment (AA):

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 or 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 implications 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.

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Article 6(4) states:

If, in spite of a negative assessment of the implications for the [Natura 2000] site and in the absence of alternative solutions, a plan or project must nevertheless be carried out for imperative reasons of overriding public interest, including those of a social or economic nature, Member States shall take all compensatory measures necessary to ensure that the overall coherence of Natura 2000 is protected. It shall inform the Commission of the compensatory measures adopted.

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Methodology

Guidance Followed Both EU and national guidance exists in relation to Member States fulfilling their requirements under the EU Habitats Directive, with particular reference to Article 6(3) and 6(4) of that Directive. The methodology followed in relation to this AA Screening has had regard to the following guidance:

 Note on Appropriate Assessments for the purposes of the Waste Water Discharge (Authorisation) Regulations, 2007 (S.I. No. 684 of 2007). Environmental Protection Agency, (EPA, 2009).

 Appropriate Assessment of Plans and Projects in Ireland: Guidance for Planning Authorities. Department of Environment, Heritage and Local Government, (DoEHLG, 2010).

 Circular L8/08 – Water Services Investment and Rural Water Programmes – Protection of Natural Heritage and National Monuments. Department of Environment, Heritage and Local Government, (DoEHLG, 2008).

 Communication from the Commission on the Precautionary Principle. Office for Official Publications of the European Communities, Luxembourg, (EC, 2000a).

 Managing Natura 2000 Sites: the provisions of Article 6 of the ‘Habitats’ Directive 92/43/EEC, Office for Official Publications of the European Communities, Luxembourg, (EC, 2000b).

 Assessment of plans and projects significantly affecting Natura 2000 sites: Methodological guidance on the provisions of Articles 6(3) and (4) of the Habitats Directive 92/43/EEC. Office for Official Publications of the European Communities, Brussels (EC, 2001).

 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. Office for Official Publications of the European Communities, Luxembourg, (EC, 2007).

 Nature and biodiversity cases: Ruling of the European Court of Justice. Office for Official Publications of the European Communities, Luxembourg (EC, 2006).

 Marine Natura Impact Statements in Irish Special Areas of Conservation: A working document, National Parks and Wildlife Service, Dublin (NPWS, 2012).

 European Communities (Birds and Natural Habitats) Regulations, 2011 (S.I. No.477 of 2011).

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 Interpretation Manual of European Union Habitats. Version EUR 28. European Commission (EC, 2013).

Stages Involved in the Appropriate Assessment Process

Stage 1: Screening / Test of Significance This process identifies whether the existing WwTP discharge is directly connected to or necessary for the management of a Natura 2000 Site(s); and identifies whether discharge is likely to have significant impacts upon a Natura 2000 Site(s) either alone or in combination with other projects or plans.

The output from this stage is a determination for each Natura 2000 Site(s) of not significant, significant, potentially significant, or uncertain effects. The latter three determinations will cause that site to be brought forward to Stage 2.

Stage 2: Appropriate Assessment This stage considers the impact of the WwTP discharge on the integrity of a Natura 2000 Site(s), either alone or in combination with other projects or plans, with respect to (1) the site’s conservation objectives; and (2) the site’s structure and function and its overall integrity. Additionally, where there are adverse impacts, an assessment of the potential mitigation of those impacts

The output from this stage is a Natura Impact Statement (NIS). This document must include sufficient information for the EPA to carry out the appropriate assessment. If the assessment is negative, i.e. adverse effects on the integrity of a site cannot be excluded, then the process must consider alternatives (Stage 3) or proceed to Stage 4.

Stage 3: Assessment of Alternatives This process examines alternative ways of achieving the objectives of the project or plan that avoid adverse impacts on the integrity of the Natura 2000 Site. This assessment may be carried out concurrently with Stage 2 in order to find the most appropriate solution. If no alternatives exist or all alternatives would result in negative impacts to the integrity of the Natura 2000 Sites then the process either moves to Stage 4 or the project is abandoned.

Stage 4: Assessment Where Adverse Impacts Remain An assessment of compensatory measures where, in the light of an assessment of Imperative Reasons of Overriding Public Interest (IROPI), it is deemed that the project or plan should proceed.

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Stage 1: Screening / Test of Significance In complying with the obligations under Article 6(3) and following the appropriate guidelines, this AA Screening has been structured as a stage by stage approach as follows:

 Description of the project;

 Identification of Natura 2000 sites potentially affected;

 Identification and description of individual and cumulative impacts likely to result;

 Assessment of the significance of any effects on the Natura 2000 sites;

 Exclusion of sites where it can be objectively concluded that there will be no significant effects; and

 Screening conclusion.

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Screening

Description of the Project The village of Gweesalia is located in western County Mayo to the southwest of Bangor. It is located at the mouth of a small inlet (‘Gweesalia Bay’) within the larger Blacksod Bay waterbody. Gweesalia WwTP is located to the north of the village and was built in 2005 to cater for a population equivalent of 700p.e.

The WWTP consists of an Activated Sludge Tank (Rotating Biological Contactor) with Secondary Settlement. The primary discharge enters a natural freshwater reed bed associated with a small stream, which discharges into Gweesalia Bay approximately 240m downstream. In addition, there is an emergency overflow associated with a pumping station.

The WWTP has the following components:  Inlet Pumps  1 No. RBC / Activated Sludge Tank  1 No. Secondary Settling Tank  Return Sludge Pumping  Sludge Holding tank

It is estimated that Gweesalia WwTP is currently serving an existing population equivalent of 192p.e. and the projected future 2023 population equivalent will be 193p.e. Based on a loading of 225l/pp/day the current and future dry weather flow for the WwTP discharge is calculated at 0.0005m3/sec.

The plant was upgraded in late 2016 to address operational and compliance issues. The upgrade works involved replacing inlet pumps, construction of a stormwater overflow from the inlet pumps to the outfall chamber and works to the aeration tank.

Effluent data for the primary discharge from 2015, 2016 and 2017 is presented in Table 1.0 together with the Urban Wastewater Treatment (UWWT) Directive standards. The effluent frequently exceeds these standards, though it is noted that they do not apply to plants < 500p.e. Effluent quality in 2017, post the upgrade works, appears to have deteriorated relative to 2016 samples.

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Table 1.0: Gweesalia WwTP Effluent Monitoring Data Total Ortho- Total Date pH BOD COD SS Nitrogen phosphate Phosphorus DO 25mg/l 125mg/l 35mg/l 10/03/2015 7.1 2 23 3 7.7 0.544 0.85 8.8 14/05/2015 7 24 110 53 21.6 2.03 2.92 7.3 21/09/2015 6.7 78 204 53 18.5 1.75 3.5 16 20/10/2015 6.9 81 274 72 34.5 3.21 4.64 17 06/11/2015 6.5 7 95 24 12.7 0.901 1.84 18 12/02/2016 7.3 2 50 26 8.12 0.578 0.84 90 03/03/2016 7.1 2 87 41 11.4 0.681 1.6 98 06/05/2016 6.7 105 266 103 26.7 2.42 4 95 05/07/2016 6.5 166 369 143 29.1 1.64 4.8 19 07/10/2016 7.1 6 90 36 12.3 0.906 1.8 63.8 05/01/2017 5.8 440 761 290 30.7 2.13 7.6 6.2

Description of the Receiving Environment and Monitoring Results

Gweesalia Bay is a small enclosed sheltered bay within Blacksod Bay characterised by mud and sandflats. There is no ambient water quality monitoring undertaken in the receiving water body, and the EPA does not have a monitoring location in proximity. Water quality in Blacksod Bay (IE_WE_360_0000) is classed by the EPA (2010-2012) as Unpolluted. There is no Water Framework Directive (WFD) Status assigned to Blacksod Bay, though in terms of risk it is ‘Strongly expected to achieve Good status’.

Blacksod Bay (including the small estuary beside Gweesalia) is a designated Shellfish Area under European Communities (Quality of Shellfish Waters) Regulation 2006 (as amended) S. I. No. 268 of 2006. It is currently a Class A Shellfish Production Area for oysters1 as operated by the Seafood Protection Authority under EC Regulation No 854/2004. Under this scheme, Class A shellfish production areas must have a microbiological standard of <230 E.coli per 100g shellfish flesh and intra-valvular liquid (and may go direct for human consumption). This classification applies from the 1st Jan to 1st September, after which the area reverts to Class B.

The Blacksod Bay Pollution Reduction Programme notes the following:  The results of monitoring undertaken for the purposes of the Shellfish Waters Directive (2006/113/EC) and Schedules 2 and 4 of the Quality of Shellfish Waters Regulations (S.I. No. 268 of 2006) do not indicate any water quality issues within / in the vicinity of this shellfish area.  Monitoring of shellfish flesh for food hygiene purposes does not indicate faecal contamination in this shellfish area.

There are two designated bathing beaches on the opposite side of Blacksod Bay, Elly Beach and Mullaghroe Beach, both of which achieved Excellent water quality in 2015.

1 http://www.sfpa.ie/SeafoodSafety/Shellfish/ClassifiedAreas.aspx

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A site visit undertaken in February 2011 as part of the former discharge licence application found no visible evidence of pollution impacts on the foreshore from land-based inputs (Gweesalia WwTP or other) , or evidence of water quality impacts within the bay. It was noted however that there was some contamination of the drain receiving the emergency overflow (associated with the pumping station).

Annex I habitats identified within Blacksod Bay in proximity to the discharge point during the site visit were mudflats and sandflats; large shallow inlets and bays and remnant saltmarsh habitats along the high tide line.

Brief Description of the Natura 2000 Sites

This section of the screening process describes the Natura 2000 sites within a 15km radius of the existing Gweesalia WwTP discharge. A 15km buffer zone has been 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.

Table 2.0 list the SACs that are within 15km of the WwTP, while Table 3.0 lists the SPA’s and Figure 1.0 shows their location in relation to Gweesalia WwTP. The qualifying interests of each of the identified Natura 2000 Sites is also provided.

Table 2.0: SACs located within 15km of the WwTP

Site Site Name Qualifying Habitats Qualify Species Code

000470 Mullet/Blacksod Bay Mudflats and sandflats not covered Lutra lutra (Otter) [1355] by seawater at low tide [1140] Complex SAC Petalophyllum ralfsii Large shallow inlets and bays [1160] (Petalwort) [1395]

Reefs [1170]

Salicornia and other annuals colonising mud and sand [1310]

Shifting dunes along the shoreline with Ammophila arenaria (white dunes) [2120]

Fixed coastal dunes with herbaceous vegetation (grey dunes) [2130]

Atlantic decalcified fixed dunes (Calluno-Ulicetea) [2150]

Machairs (* in Ireland) [21A0]

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Site Site Name Qualifying Habitats Qualify Species Code

Natural eutrophic lakes with Magnopotamion or Hydrocharition - type vegetation [3150]

Alkaline fens [7230]

000534 Owenduff/Nephin Oligotrophic waters containing very Salmo salar (Salmon) few minerals of sandy plains [1106] Complex SAC (Littorelletalia uniflorae) [3110] Lutra lutra (Otter) [1355] Natural dystrophic lakes and ponds [3160] Drepanocladus vernicosus (Slender Green Feather- Water courses of plain to montane moss) [1393] levels with the Ranunculion fluitantis and Callitricho-Batrachion Saxifraga hirculus (Marsh vegetation [3260] Saxifrage) [1528]

Northern Atlantic wet heaths with Erica tetralix [4010]

Alpine and Boreal heaths [4060]

Juniperus communis formations on heaths or calcareous grasslands [5130]

Blanket bogs (* if active bog) [7130]

Transition mires and quaking bogs [7140]

2998 West Connacht Coast Tursiops truncatus (Common Bottlenose SAC Dolphin) [1349]

000476 Carrowmore Lake Blanket bogs (* if active bog) [7130] Drepanocladus vernicosus (Slender Green Feather- Complex SAC Depressions on peat substrates of moss) [1393] the Rhynchosporion [7150] Saxifraga hirculus (Marsh Saxifrage) [1528]

000472 Broadhaven Bay SAC Mudflats and sandflats not covered by seawater at low tide [1140]

Large shallow inlets and bays [1160]

Reefs [1170]

Atlantic salt meadows (Glauco- Puccinellietalia maritimae) [1330]

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Site Site Name Qualifying Habitats Qualify Species Code

Submerged or partially submerged sea caves [8330]

Table 3.0: SPAs located within 15km of the WwTP

Site Site Name Special Conservation Interests Code

004037 Blacksod Bay/Broad Haven SPA Great Northern Diver (Gavia immer) [A003] Light-bellied Brent Goose (Branta bernicla hrota) [A046] Common Scoter (Melanitta nigra) [A065] Red-breasted Merganser (Mergus serrator) [A069] Ringed Plover (Charadrius hiaticula) [A137] Sanderling (Calidris alba) [A144] Dunlin (Calidris alpina) [A149] Bar-tailed Godwit (Limosa lapponica) [A157] Curlew (Numenius arquata) [A160] Sandwich Tern (Sterna sandvicensis) [A191] Dunlin (Calidris alpina schinzii) [A466] Wetland and Waterbirds [A999] 004111 Duvillaun Islands SPA Fulmar (Fulmarus glacialis) [A009] Storm Petrel (Hydrobates pelagicus) [A014] Barnacle Goose (Branta leucopsis) [A045] 004227 Mullet Peninsula SPA Corncrake (Crex crex) [A122] 004098 Owendull/Nephin Complex SPA Merlin (Falco columbarius) [A098] Golden Plover (Pluvialis apricaria) [A140] 004052 Carrowmore Lake SPA Sandwich Tern (Sterna sandvicensis) [A191]

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Figure 1.0: Natura 2000 Sites

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Potential Impacts of the Existing Discharge and Likely Significant Effects on Natura 2000 Sites

The purpose of this section of the screening is to examine the possibility that the existing discharge, either individually or in combination with other plans and projects, may result in significant negative effects on the Conservation Objectives and the integrity of the Natura 2000 Sites identified.

The most apparent potential risk to a Natura 2000 Site(s) from a WwTP discharge is to the water quality of the receiving environment, and the assessment therefore needs to consider whether the receiving environments water quality has the potential to interact with the qualifying interests of the Natura 2000 Sites identified. As the WwTP discharges to Gweesalia Bay in close proximity to Mullet/Blacksod Bay Complex SAC and Blacksod Bay/Broad Haven SPA , there is a potential pathway for effects to these Natura 2000 sites.

The Conservation Objectives of these sites (NPWS, 2014a and NPWS, 2014b) were therefore reviewed as part of this Screening Assessment.

Other sites identified in Table 2.0 and 3.0 are either terrestrial, or too remotely connected hydrologically for there to be any potential for impact given the intervening dilution and dispersal available in the coastal waters.

The existing WwTP discharge is not directly connected with or necessary to the management of the site for nature conservation.

Direct, Indirect or Secondary Impacts

The primary discharge is to a freshwater stream ca. 240m outside of the SAC/SPA. The stream receives further input from another stream from the north before discharging into Gweesalia Bay. It is also noted that discharge is into an area of reedbed, which will have a natural capacity to remove nutrients. The emergency overflow associated with the pumping station has resulted in contamination in a drain in the past, though it is understood not to spill frequently, and no signs of pollution within downstream SAC/SPA habitats were noted.

Despite recent upgrade works however, the quality of the effluent appears to have deteriorated recently. Given the proximity to the downstream SAC/SPA, localised adverse effects to water quality cannot be ruled out if the WwTP continues to discharge poorly treated effluent.

The habitats mudflats and sandflats, large shallow inlets and bays, and reefs, have the potential to be impacted by a discharge from Gweesalia WwTP. The waterbird species listed as special conservation interests for the SPA are likely to use the habitats within Gweesalia Bay for foraging purposes and therefore also have the potential to be impacted. It is considered that given the recent deterioration in effluent quality, and the potential for localised water quality impacts, that significant effects to the conservation objectives of qualifying interests, or overall site integrity, of Mullet/Blacksod Bay Complex SAC and Blacksod Bay/Broad Haven SPA, cannot be ruled out at this stage.

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In accordance with the Waste Water Discharge (Authorisation) Regulations 2007 (S.I. No. 684 of 2007), and considering the objective information provided above, it is concluded that Stage 2 Appropriate Assessment is required.

Possible Cumulative Impacts with other Plans and Projects in the Area

As part of Stage 1 Screening, in addition to the existing discharge, other relevant projects and plans in the relevant region must also be considered. This step aims to identify at this early stage any possible significant effects on the Natura 2000 Sites from the existing discharge in- combination or cumulative with other plans and projects. Existing plans which have been examined include:

 Mayo County Development Plan 2014-2020;  Blacksod Bay Pollution Reduction Programme 2012;  Mayo West Water Management Unit Action Plan; and  County Mayo Biodiversity Action Plan 2010-2015.

The above plans have been assessed in accordance with Article 6(3) of the Habitats Directive and Part XAB of the Planning and Development Act, 2000, and are not envisaged to result in significant effects on the integrity of the Natura 2000 network.

Untreated effluent currently discharges to Blacksod Bay from Bellmullet WwTP, however a new treatment plant is in the process of being built at this location.

Mayo County Council online planning system was reviewed for any significant recent developments that have the potential to contribute to cumulative impacts. No projects with the potential to cumulatively impact on the Mullet /Blacksod Bay Complex SAC or Blacksod Bay/Broad Haven SPA with the existing Gweesalia WwTP discharge were identified.

Summary of Potential Impacts and Likely Significant Effects Table 4.0 provides a summary of the likely significant impact of the existing discharge on the conservation objectives of the Natura 2000 sites potentially linked to the existing discharge as identified in Tables 2.0 and Table 3.0.

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Table 4.0: Potential Significant Impacts on Natura 2000 sites from the Existing Discharge

Site Name Direct Indirect/ Resource Emissions Excavation Transportation Duration of Impacts Secondary Requirements (Disposal to Requirements Requirements Construction, (Drinking Water Land, Water or Operation, Abstraction Etc.) Air) Decommissioning Mullet/Blacksod Bay Potential Potential impact No impact on qualifying Potential impact No impact on qualifying No impact on No impact on qualifying impact on the on the water interest on the water interest qualifying interest interest Complex SAC water quality of quality of quality of Gweesalia Bay Gweesalia Bay as Gweesalia Bay as as a result of a result of the a result of the the WwTP WwTP discharge WwTP discharge discharge Owenduff/Nephin No impact on No impact on No impact on qualifying No impact on No impact on qualifying No impact on No impact on qualifying qualifying qualifying interest interest qualifying interest interest qualifying interest interest Complex SAC interest West Connacht Coast No impact on No impact on No impact on qualifying No impact on No impact on qualifying No impact on No impact on qualifying qualifying qualifying interest interest qualifying interest interest qualifying interest interest SAC interest Carrowmore Lake No impact on No impact on No impact on qualifying No impact on No impact on qualifying No impact on No impact on qualifying qualifying qualifying interest interest qualifying interest interest qualifying interest interest Complex SAC interest Broadhaven Bay SAC No impact on No impact on No impact on qualifying No impact on No impact on qualifying No impact on No impact on qualifying qualifying qualifying interest interest qualifying interest interest qualifying interest interest interest Blacksod Bay/Broad Potential Potential impact No impact on qualifying Potential impact No impact on qualifying No impact on No impact on qualifying impact on the on the water interest on the water interest qualifying interest interest Haven SPA water quality of quality of quality of Gweesalia Bay Gweesalia Bay as Gweesalia Bay as as a result of a result of the a result of the the WwTP WwTP discharge WwTP discharge discharge Duvillaun Islands SPA No impact on No impact on No impact on qualifying No impact on No impact on qualifying No impact on No impact on qualifying qualifying qualifying interest interest qualifying interest interest qualifying interest interest interest Mullet Peninsula SPA No impact on No impact on No impact on qualifying No impact on No impact on qualifying No impact on No impact on qualifying qualifying qualifying interest interest qualifying interest interest qualifying interest interest interest Owendull/Nephin No impact on No impact on No impact on qualifying No impact on No impact on qualifying No impact on No impact on qualifying qualifying qualifying interest interest qualifying interest interest qualifying interest interest

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Site Name Direct Indirect/ Resource Emissions Excavation Transportation Duration of Impacts Secondary Requirements (Disposal to Requirements Requirements Construction, (Drinking Water Land, Water or Operation, Abstraction Etc.) Air) Decommissioning Complex SPA interest Carrowmore Lake SPA No impact on No impact on No impact on qualifying No impact on No impact on qualifying No impact on No impact on qualifying qualifying qualifying interest interest qualifying interest interest qualifying interest interest interest

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Likely Changes to the Natura 2000 Site(s) The likely changes that will arise from the existing WwTP discharge have been examined in the context of a number of factors that could potentially affect the integrity of the identified Natura 2000 Sites. Overall, it has been found that the existing discharge has the potential to affect the integrity of the identified Natura 2000 Sites, alone or in-combination with other plans or projects.

Table 5.0: Likely Affect on Natura 2000 Sites

Site Name Reduction Disturbance Habitat or Reduction Changes in Climate of Habitat to Key Species in Species Key Indicators Change Area Species Fragmentation Density of Conservation Value (Water Quality Etc.) Mullet/Blacksod Bay Potential Potential Potential Potential Potential None negative negative negative impact negative negative impact Complex SAC impact impact impact Owenduff/Nephin None None None None None None Complex SAC West Connacht Coast None None None None None None SAC Carrowmore Lake None None None None None None Complex SAC Broadhaven Bay SAC None None None None None None Blacksod Bay/Broad Potential Potential Potential Potential Potential None negative negative negative impact negative negative impact Haven SPA impact impact impact Duvillaun Islands SPA None None None None None None Mullet Peninsula SPA None None None None None None Owendull/Nephin None None None None None None Complex SPA Carrowmore Lake SPA None None None None None None

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Screening Conclusion

From the current screening assessment, taking account of supporting documentation, there is the potential for on-going significant cumulative impacts affecting the Mullet/Blacksod Bay Complex SAC and Blacksod Bay/Broad Haven SPA arising from the operation of the Gweesalia WwTP. From the examination of the information available it is considered that the discharge has the potential to result in significant impacts to the NATURA 2000 network, specifically in relation to direct and cumulative impacts affecting the conservation interests of the Mullet/Blacksod Bay Complex SAC and Blacksod Bay/Broad Haven SPA.

On the basis of the findings of this Screening for Appropriate Assessment, it is concluded that the current Gweesalia WwTP discharge to Gweesalia Bay:

(i) is not directly connected with or necessary to the management of a Natura 2000 site; and

(ii) may have significant effects on Natura 2000 sites, the Mullet/Blacksod Bay Complex SAC and Blacksod Bay/Broad Haven SPA.

Therefore, applying the Precautionary Principle and in accordance with Article 6(3) of the Habitats Directive, the current WwTP discharge at Gweesalia will be brought forward for a Stage 2 Appropriate Assessment.

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Stage 2: Appropriate Assessment

In this section, the Mullet/Blacksod Bay Complex SAC and Blacksod Bay/Broad Haven SPA, which have been determined as requiring AA, are described and all the potential impacts resulting from the Gweesalia WwTP discharge are discussed in relation to the conservation objectives of these designated sites.

Description of the Natura 2000 Site Affected

Mullet/Blacksod Bay Complex SAC2

This large coastal site, located in north-west Co. Mayo, comprises much of the Mullet Peninsula, the sheltered waters of Blacksod Bay and the low-lying sandy coastline from Belmullet to Kinrovar. The site displays an excellent range of coastal and marine habitats. Blacksod Bay is 16 km in length and 8 km wide at the mouth. It is a shallow bay, reaching a maximum depth of 19 m and with weak tidal streams. The bay has a good range of representative littoral and sublittoral sediment communities, and also infralittoral reefs. Large areas of machair, a priority habitat on Annex I of the E.U. Habitats Directive, are found within this extensive coastal site. Fixed dunes with herbaceous vegetation, another Annex I priority habitat, have an extensive distribution throughout the site and are particularly well developed in the middle and south of the Mullet peninsula. Smaller areas of shifting dunes with Marram are found in most of the dune areas within the site and typically occur along the most exposed ridges of sand dune systems. Saltmarshes occur in a number of places, notably at Elly Bay, Salleen Harbour, Bunnahowen, Doolough and Gweesalia. The site also includes shallow freshwater lakes, Termoncarragh Lough, Cross Lough and Leam Lough. Marsh and swamp vegetation is well developed around Termoncarragh Lough, and of particular note is a fine example of alkaline fen. The Annex II liverwort species Petalophyllum ralfsii has been recorded from damp areas of machair at Doolough and Dooyork. The Red Data Book plant species Narrow-leaved Marsh-orchid (Dactylorhiza traunsteineri) also occurs. Otter, a species also listed under Annex II of the Habitats Directive, is well distributed throughout the site.

Description of the Conservation Interests of the SAC

Annex I Habitats3 The Mullet/Blacksod Bay Complex SAC supports ten Annex I habitats:  Mudflats and sandflats not covered by seawater at low tide [1140]  Large shallow inlets and bays [1160]  Reefs [1170]  Salicornia and other annuals colonising mud and sand [1310]  Shifting dunes along the shoreline with Ammophila arenaria (white dunes) [2120]  Fixed coastal dunes with herbaceous vegetation (grey dunes) [2130]  Atlantic decalcified fixed dunes (Calluno-Ulicetea) [2150]  Machairs (* in Ireland) [21A0]  Natural eutrophic lakes with Magnopotamion or Hydrocharition - type vegetation [3150]

2 Extracted from NPWS Site Synopsis Rev 13, Version date 26.08.2013 3 In subsequent text and tables the full Annex I habitat names are shortened as per NPWS (2013a)

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 Alkaline fens [7230]

Site specific conservation objectives have been developed for Mullet/Blacksod Bay Complex SAC (NPWS. 2014a). They confirm that the bay into which Gweesalia WwTP discharges supports the following qualifying interests: mudflats and sandflats (dominated by sand with Angulus tenuis and Pygospio elegans community complex), large shallow inlets and bays, reef (at a point on the northern side of the bay) and potential saltmarsh habitats. The overall conservation objective for these habitats is to maintain their favourable conservation status.

The dune habitats are terrestrial in nature and therefore unconnected to the potential impacts from a WwTP discharge. The other qualifying interests listed – natural eutrophic lakes, alkaline gens and salicornia muds, are located at a distance to the study area (NPWS, 2014a).

Table 6.0: Qualifying Habitats within Gweesalia Bay

Site Qualifying Habitats Present within potential zone of influence of the discharge

Mullet/Blacksod Tidal mudflats Yes Bay Complex SAC Large shallow inlets and bays Yes

Reefs Yes

Salicornia mud No

Marram dunes (white dunes) No

Fixed dunes (grey dunes)* No

Decalcified dune heath* No

Machair (* in Ireland) No

Natural eutrophic lakes No

Alkaline fens No

Annex II Species The Mullet/Blacksod Bay Complex SAC supports two Annex II species:

 Lutra lutra (Otter) [1355]  Petalophyllum ralfsii (Petalwort) [1395]

Otter are found throughout the Mullet/Blacksod Bay Complex including Gweesalia Bay (NPWS, 2014a) and there are records of otter activity within 2km of Gweesalia Bay (NBDC website). Otters have two basic requirements: aquatic prey and safe refuges where they can rest. This species is dependent on fish stocks which are ultimately dependent on water quality.

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At the outer edge of Gweesalia bay there are Annex I sand dune habitats supporting the Annex II species Petalwort, however this species or its supporting habitats have no potential to be impacted by the discharge.

Both qualifying interests have the overall conservation objective ‘to maintain’ their favourable conservation status.

Table 7.0: Qualifying Species within Gweesalia Bay

Site Qualifying Suitable Habitat Present Species

Mullet/Blacksod Otter Yes Bay Complex SAC Petalwort Yes

Conservation Objectives of the Mullet/Blacksod Bay Complex SAC

Article 6 of the Habitats Directive states that:

Any plan or project not directly connected with or necessary to the management of the site but likely to have a significant effect thereon, either individually or in combination with other plans or projects, shall be subject to appropriate assessment of its implications of the site in view of the site’s conservation objectives.

The importance of a site designated under the Habitats Directive is defined by its qualifying features or interests. Qualifying interests for any Natura 2000 site are listed on a pro forma, called the Natura 2000 standard data form, which forms the basis of the rationale behind designation, and informs the Conservation Management Plan for targeted management and monitoring of key species and habitats.

Favourable conservation status of a habitat is achieved when:  Its natural range, and area it covers within that range, are stable or increasing;  The specific structure and functions which are necessary for its long-term maintenance exist and are likely to continue to exist for the foreseeable future; and  The conservation status of its typical species is favourable.

The favourable conservation status of a species is achieved when:  Population dynamics data on the species concerned indicate that it is maintaining itself on a long-term basis as a viable component of its natural habitats;  The natural range of the species is neither being reduced nor is likely to be reduced for the foreseeable future; and  There is, and will probably continue to be, a sufficiently large habitat to maintain its populations on a long-term basis.

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Site specific conservation objectives have been developed for the Mullet/Blacksod Bay Complex SAC (NPWS, 2014a). Objectives for the relevant qualifying interests, i.e. those with the potential to be impacted by a WwTP discharge, are provided below.

Tidal mudflats:  Attribute: Habitat Area; Target: The permanent habitat area is stable or increasing subject to natural processes.  Attribute: Community Distribution;  Target: Conserve the following community types in a natural condition: Mobile sand with Bathyporeia guilliamsoniana community; Sand with Angulus tenuis and Pygospio elegans community complex.

Large Shallow Inlets and Bays:  Attribute: Habitat Area; Target: The permanent habitat area is stable or increasing subject to natural processes.  Attribute: Community extent; Target: Maintain the extent of the Zostera and maerl-dominated communities and Serpula vermicularis-dominated community complex, subject to natural processes.  Attribute: Community structure – shoot density; Target: Conserve the high quality of Zostera-dominated community, subject to natural processes.  Attribute: Community structure – biological composition; Target: Conserve the high quality of the maerl-dominated community complex, subject to natural processes.  Attribute: Community structure – biological composition;  Target: Conserve the high quality of the Serpula vermicularis-dominated community complex, subject to natural processes.  Attribute: Community distribution;  Target: Conserve the following community types in a natural condition: Sand with Gastrosaccus spinifer community complex, Fine sand with Angulus fabula community complex, Intertidal reef community complex, Sheltered subtidal reef community complex and Laminaria-dominated community complex.

Reefs:  Attribute: Habitat Area; Target: The permanent habitat area is stable or increasing subject to natural processes.  Attribute: Distribution; Target: The distribution of reefs remains stable, subject to natural processes.  Attribute: Community extent; Target: Maintain the extent of the Serpula vermicularis-dominated community complex, subject to natural processes.  Attribute: Community structure – biological composition; Target: Conserve the high quality of the Serpula vermicularis-dominated community complex, subject to natural processes.  Attribute: Community structure – biological composition;

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Target: Conserve the following community types in a natural condition – Intertidal reef community complex, Sheltered subtidal reef community, Laminaria-dominated community complex.

Otter:  Attribute: Distribution; Target: No significant decline.  Attribute: Extent of terrestrial habitat; Target: No significant decline – Area mapped and calculated as 168.7ha.  Attribute: Extent of marine habitat; Target: No significant decline– Area mapped and calculated as 929.6ha.  Attribute: Extent of freshwater habitat; Target: No significant decline – Area mapped and calculated as 31.0km.  Attribute: Extent of freshwater lake/lagoon habitat; Target: No significant decline – Area mapped and calculated as 87.7ha.  Attribute: Couching sites and holts; Target: No significant decline.  Attribute: Fish biomass available; Target: No significant decline.  Attribute: Barriers to connectivity; Target: No significant increase.

Blacksod Bay/ Broad Haven SPA4

Situated in the extreme north-west of Co. Mayo, this site comprises a number of bays and inlets including Sruwaddacon Bay, Moyrahan Bay, Traw-Kirtaun, Blind Harbour, Tullaghan Bay, and the various sheltered bays and inlets in Blacksod Bay, including Trawmore Bay, Feorinyeeo Bay, Saleen Harbour, Elly Bay and Elly Harbour. At low tide extensive areas of intertidal sand and mudflats are exposed. These support a well-developed macro-invertebrate fauna. Salt marshes, which are often on a peat substrate, fringe parts of the site and provide useful roosts for the wintering waterfowl. Also included within the site are two small lakes on the Mullet Peninsula, Cross Lough and Leam Lough, and some areas of machair at Fahy, Doolough, Dooyork and Srah.

The site is of high ornithological importance for its excellent diversity of wintering waterbirds, including internationally important populations of Great Northern Diver and Light-bellied Brent Goose, and nationally important populations of seven other species. Of particular note is the usage of the site by over 4% of the all-Ireland population of Ringed Plover. It is also a nationally important breeding site for Sandwich Tern and Dunlin (subsp. schinzii). It is of note that eight of the species that occur regularly are listed on Annex I of the E.U. Birds Directive, i.e. Great Northern Diver, Red-throated Diver, Golden Plover, Dunlin (subsp. schinzii), Bar-tailed Godwit, Sandwich Tern, Common Tern and Arctic Tern. Blacksod Bay and Broad Haven is a Ramsar Convention site.

4 Extracted from NPWS Site Synopsis (dated 18/10/2013)

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Description of the Conservation Interests of the SPA

The SPA is designated for the following bird species:  Great Northern Diver (Gavia immer) [A003]  Light-bellied Brent Goose (Branta bernicla hrota) [A046]  Common Scoter (Melanitta nigra) [A065]  Red-breasted Merganser (Mergus serrator) [A069]  Ringed Plover (Charadrius hiaticula) [A137]  Sanderling (Calidris alba) [A144]  Dunlin (Calidris alpina) [A149]  Bar-tailed Godwit (Limosa lapponica) [A157]  Curlew (Numenius arquata) [A160]  Sandwich Tern (Sterna sandvicensis) [A191]  Dunlin (Calidris alpina schinzii) [A466]  Wetland and Waterbirds [A999]

Information on populations (where available), requirements and sensitivities of key species are considered in more detail below with data taken from Crowe (2005), Colhoun & Cummins, (2013), BirdWatch Ireland website and iWeBS data5 and NPWS (2014c).

Great northern diver The Great Northern Diver breeds in Canada, parts of the northern United States, Greenland and Alaska with a smaller breeding population in Iceland. The species winters along coasts of Europe and America. The species typically occurs further offshore however, they tend to come closer to shore and into sheltered estuaries during periods of bad weather. iWeBS counts for 2014/15 were 74, which is consistent with the baseline population (1990/00-2003/04) count of 67.

The light-bellied brent geese that winter in Ireland are part of the population that breed in the Canadian Arctic. They feed on Zostera beds, as well as on algae and in adjacent terrestrial fields when these resources become depleted. iWeBS counts for 2014/15 were 322, which is consistent with the baseline population (1990/00-2003/04) count of 279.

The Common Scoter is polytypic with a northerly breeding distribution that extends across northwest and northern Europe, Siberia and parts of North America. There is a relatively small Irish breeding population that breed at inland lakes. During winter, these birds occur off the coast joined by other wintering individuals from Iceland and Scandinavia. iWeBS counts for 2014/15 were 2100, which are significantly higher than the baseline population (1990/00-2003/04) count of 510.

Red-breasted Merganser winter in brackish and marine waters, particularly in shallow protected estuaries and bay and lagoons, and also offshore. They feed on fish, predominately small cod, hake and plaice. iWeBS counts for 2014/15 were 87, which is consistent with the baseline population (1990/00-2003/04) count of 83.

The Ringed Plover breeds a cross Arctic and temperate zones from the east coast of Baffin Island, Greenland, across northern Europe and the Russian tundra to the coasts of the Bering Sea. Three subspecies are generally recognised of which the nominate subspecies, C. h.

5 www.birdwatchireland.ie iWeBS site summary data for Blacksod Bay

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hiaticula, breeds in northern Europe (including Ireland) and winters in Europe and north-west Africa. iWeBS Counts for 2014/15 were 594, which is consistent with the baseline population (1990/00-2003/04) count of 590.

Sanderling are a winter visitor from Siberia. They are mostly found along sandy coastlines, especially non-estuarine. They feed predominately on small invertebrates. iWeBS counts for 2014/15 were 331, which are higher than the baseline population (1990/00-2003/04) count of 171.

Dunlin are common along coastal areas in Ireland, especially on tidal mudflats and estuaries. They feed on small invertebrates of estuarine mudflats, particularly polychaete works and small gastropods. They feed in the muddier sections of the estuaries close to the tide edge. The majority of Dunlin wintering in Ireland are C. a. alpina that originate from the western part of their breeding range and moult mainly in the Wadden Sea before starting to arrive in Ireland during October. Ireland has a small and declining breeding population of Calidris alpina schinzii which are believed to winter mainly in west Africa. This subspecies breeds within the areas of machair in the SPA. iWeBS counts for 2014/15 (wintering Dunlin) were 592, which indicate numbers are much reduced relative to the baseline population (1990/00-2003/04) count of 1255.

Bar-tailed Godwit are a winter visitor from Scandanavia. They winter entirely in coastal habitats. They feed on invertebrates, predominately polychaete worms. iWeBS counts for 2014/15 were 740, which is consistent with the baseline population (1990/00-2003/04) count of 664.

Curlew winter in a wide range of wetland habitats both coastal and inland. They feed mostly on invertebrates including ragworms, crabs and molluscs. iWeBS counts for 2014/15 were 609, which is consistent with the baseline population (1990/00-2003/04) count of 567.

Sandwich Term are a summer visitor to all Irish coasts. They winter in Southern Europe and Africa. They are amber-listed in Ireland due to their localised breeding population. They feed mainly on surface dwelling fish. Inishderry Island has a nationally important breeding colony of Sandwich Tern within the SPA, with a baseline (1995) population of 81 breeding pairs.

Wetlands are also listed as a feature of the SPA. Eutrophication has the potential to alter wetland habitats as certain wetland species would be sensitive to changes in water quality. Influxes in nutrients can result in a shift in species composition toward more tolerant competitive species and a loss of rarer species which typically require lower nutrient inputs. Floristic diversity generally decreases and sensitive invertebrate species may be lost. Some aquatic plants and algae may increase in biomass. The discharge enters a freshwater stream at the mouth of the bay, with the closest intertidal wetland habitats comprising mudflats.

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Table 8.0: Qualifying SPA Features in Gweesalia Bay

Site Qualifying Species Suitable habitat present within potential zone of influence of discharge

Blacksod Great northern diver Yes Bay/Broad Common scoter Yes Haven Light-bellied brent goose Yes SPA Red-breasted merganser Yes Ringed plover Yes Sanderling Yes Dunlin Yes Bar-tailed godwit Yes Curlew Yes Sandwich tern Yes Wetland and waterbirds Yes

Conservation Objectives of the SPA6

To maintain or restore the favourable conservation condition of the bird species listed as Special Conservation Interests for this SPA:

 Great Northern Diver (Gavia immer) [A003]  Light-bellied Brent Goose (Branta bernicla hrota) [A046]  Common Scoter (Melanitta nigra) [A065]  Red-breasted Merganser (Mergus serrator) [A069]  Ringed Plover (Charadrius hiaticula) [A137]  Sanderling (Calidris alba) [A144]  Dunlin (Calidris alpina) [A149]  Bar-tailed Godwit (Limosa lapponica) [A157]  Curlew (Numenius arquata) [A160]  Sandwich Tern (Sterna sandvicensis) [A191]  Dunlin (Calidris alpina schinzii) [A466]  Wetland and Waterbirds [A999]

Detailed conservation objectives further define the attributes and targets necessary to maintain the favourable conservation status of the species listed above as follows:  Attribute: Population Trend; Target: Long term population trend stable or increasing.  Attribute: Distribution; Target: No significant decrease in the numbers or range of areas used by bird species, other than that occurring from natural patterns of variation.

With regards the nine non-breeding waterbird species of Special Conservation Interest for Blacksod Bay/Broad Haven SPA, and based on the long-term population trend for the site, it has been determined that:-

6 NPWS (2014b) Conservation Objectives: Blacksod Bay/Broad Haven SPA 004037. Version 1. National Parks and Wildlife Service, Department of Arts, Heritage and the Gaeltacht.

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 1 species is currently considered as highly unfavourable (Dunlin);  2 species are considered as intermediate (unfavourable) (Common Scoter and Curlew);  6 species are currently considered as favourable (Light-bellied Brent Goose, Red- breasted Merganser, Great Northern Diver, Ringed Plover, Sanderling and Bar-tailed Godwit).

It is noted that Common Scoter, Curlew and Dunlin are all declining nationally, and Common Scoter and Curlew are also declining internationally.

Impact Prediction

Impacts on Water Quality The aquatic conservation interests of the Mullet/Blacksod Bay SAC and Blacksod Bay/Broad Haven SPA are directly dependant on the aquatic environment and as the Gweesalia WwTP discharges to a small stream just upstream of the SAC/SPA designation, there is a connection between the WwTP discharge and the ecological receptors of the SAC/SPA.

While Gweesalia WwTP was upgraded in 2016, improvements in effluent quality are not yet evident. While the water quality of the waterbody is classed as Unpolluted, there is no local ambient monitoring data for Gweesalia Bay. With the current poor quality effluent, the possibility of localised water quality impacts cannot be ruled out. It is noted that as the p.e. for the plant is low and the presence of reedbed and additional freshwater dilution prior to reaching the SAC/SPA, that any localised eutrophication impacts would be anticipated to be very minor.

Cumulative impacts in the catchment possibly pose the greatest risk to the conservation objectives. The potential threat(s) of the Gweesalia WwTP on water quality (long term or single event) is greatly increased when taken in combination with other water quality concerns in the catchment.

The only other urban wastewater discharge to Blacksod Bay is at Belmullet, where a new treatment plant is currently being constructed. There are further point discharge pressures on Blacksod Bay from several Section 4 licensed facilities and an EPA licensed facility. Over 90% of Total Phosphorus is diffuse however, with agriculture accounting for over 55% of TP and forestry accounting for just under 30%.

Other impacts which have the potential to act cumulatively and impact on the SAC result from the following:

 Chemical fertiliser application to agricultural lands (the main fertilisers in use supply nitrogen, phosphorus, potassium and sulphur);  Agricultural practices such as ploughing leads to greater mineralisation and nitrification, and in the case of old grassland, it can result in an increase in the release of nitrogen over a number of years (OECD, 1986);  Artificial drainage increases nitrate leaching and reduce the morphological qualities of watercourses, thereby reducing the quality of habitat for flora and fauna;

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 Endocrine disruptors in domestic sewage, including the main active component in the oral contraceptive pill, can interfere with the endocrine system of plants and animals which controls a wide range of processes including metabolism, growth and reproduction. Effects include a high degree of intersexuality downstream of sewage works (Routledge et al. 1998);  Forestry may alter water quality indirectly through increased evaporation losses and hence an increase in solute concentrations; and  On-site wastewater treatment systems, poorly performing septic tank units and other small effluent systems can be significant sources of nutrients to rivers.

Impacts on Annex I Habitats

Aquatic Annex I habitats considered in this assessment are tidal mudflats, large shallow inlets and bays and Reefs, which are all found within Gweesalia Bay. The other qualifying habitats are outside the zone of influence of the discharge – the dune and wetland (fen, lake) habitats are hydrologically unconnected, while the only identified area of Salicornia mud is located a significant distance away from Gweesalia Bay.

No pressures/threats related to urban waste water or discharges are listed in the Natura 2000 Data form for the SAC. Furthermore these habitats are at favourable conservation status within the SAC with an objective ‘to maintain’ this status. This would indicate that the ongoing discharge from Gweesalia WwTP has not impacted upon these habitats to date.

However the quality of the discharge appears to have deteriorated recently, and a continued poor quality effluent discharge, or further deterioration, could potentially result in minor localised eutrophication impacts in Gweesalia Bay. Eutrophication could potentially result in changes to the biological communities which characterise these habitats with a reduction in diversity and a shift toward more tolerant species, thus affecting their conservation objectives.

Table 9.0: Qualifying Habitats Potentially Impacted by WwTP Discharge

Qualifying Habitats Potential Impacts Brief Explanation Mitigation required

Tidal mudflats Yes Potential to be impacted by localised Yes eutrophication in Gweesalia Bay. Large shallow inlets and Yes Potential to be impacted by localised Yes bays eutrophication in Gweesalia Bay. Reefs Yes Potential to be impacted by localised Yes eutrophication in Gweesalia Bay.

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Salicornia mud No Habitat not present within the potential No zone of influence of the discharge. Marram dunes (white No No pathway connection to this No dunes) terrestrial coastal habitat. Fixed dunes (grey dunes)* No No pathway connection to this No terrestrial coastal habitat. Decalcified dune heath* No No pathway connection to this No terrestrial coastal habitat. Machair (* in Ireland) No No pathway connection to this No terrestrial coastal habitat. Natural eutrophic lakes No No pathway connection to this wetland No habitat. Alkaline fens No No pathway connection to this wetland No habitat.

Impacts on Annex II Species

The impact of the Gweesalia WwTP discharge must be considered with respect to foraging otter, which are known to occur throughout the SAC. While otter is dependent on fish stocks, which are ultimately dependent on water quality, the relevant conservation objective relates to fish biomass. While any localised minor eutrophication impacts from Gweesalia WwTP could impact on fish diversity, it would not have the potential to impact on the overall biomass of fish available to otter in the SAC. This species continues to maintain favourable conservation status in the SAC, and while the effluent quality is currently poor, any ongoing discharge is not predicted to significantly impact the conservation objectives of this species.

Petalwort is a bryophyte associated with machair habitat, and is found on the other headlands of Gweesalia Bay. There is no connectivity between this species, or its supporting habitat, and the ongoing WwTP discharge.

Table 10.0: Qualifying Species Potentially Impacted by WwTP Discharge

Qualifying Species Potential Brief Explanation Mitigation Impact Required

Otter No Minor eutrophication impacts would not have the No potential to affect the relevant conservation objectives for this species. Petalwort No No pathway connection to this rare bryophyte or its No coastal machair habitat.

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Impacts on Special Conservation Interests of the SPA

The impact of the Gweesalia WwTP discharge must be considered with respect to wintering birds which are known to forage and roost within Gweesalia Bay. The Conservation Objectives Supporting Document (NPWS, 2014c) identifies that Gweesalia Bay is the SPA subsite OD490 and that all wintering Special Conservation Interests occur within this subsite. The SPA waterbirds are directly dependant on the intertidal/marine habitats of the bay for foraging/prey. No pressures/threats related to urban waste water or discharges are listed in the Natura 2000 Data form for SPA. These species would also have low sensitivity to any minor eutrophication effects in the Bay. While any localised minor eutrophication impacts from Gweesalia WwTP could impact on community diversity within these habitats, it would not have the potential to impact on the overall food resources available to waterbirds. Most of these species continue to maintain favourable conservation status in the SPA, and for those that don’t the declines are consistent with national trends indicating wider population/climate issues. Although the effluent quality is currently poor, any ongoing discharge is not predicted to significantly impact the conservation objectives of any Special Conservation Interest of Blacksod Bay/Broad Haven SPA.

Table 11.0: Special Conservation Interests Potentially Impacted by WwTP Discharge

Special Conservation Potential Brief Explanation Mitigation Interests Impact Required

Great northern diver No No impact to Special Conservation Interests No Common scoter of the SPA is predicted due to low sensitivity Light-bellied brent goose of the species to minor levels of Red-breasted merganser eutrophication. Ringed plover Sanderling Dunlin Bar-tailed godwit Curlew Sandwich tern Wetland and waterbirds

Mitigation Measures

Despite a recent upgrade and the lack of capacity issues at the plant, the effluent quality being discharged from Gweesalia WwTP has recently deteriorated. Considering the precautionary principle, this assessment has found that the possibility of an adverse localised impact to the Annex I habitats of Gweesalia Bay cannot be ruled out. Mitigation measures are described below to address potential impacts:

 Implementation of an appropriate wastewater treatment system at Gweesalia WwTP;  Implementation of an appropriate performance management system for the plant;

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 Ensure that the capacity of the WwTP is not exceeded; and  Continued monitoring of the effluent quality.

Stage 2 Appropriate Assessment Conclusion Statement The current Appropriate Assessment has been prepared following the EPA (2009) ‘Note on Appropriate Assessments for the purposes of the Waste Water Discharge (Authorisation) Regulations, 2007 (S.I. No. 684 of 2007)’. The Department of the Environment, Heritage and Local Government guidance ‘Appropriate Assessment of Plans and Projects in Ireland. Guidance for Planning Authorities’ (DoEHLG, 2009a) has also been taken into account. Therefore the current assessment for the Waste Water Certificate of Authorisation investigates the potential adverse effects on the aquatic qualifying interests of the Natura 2000 network arising from the plant discharge, in combination with other plans / projects affecting the aquatic environment. The assessment considers whether the discharge, alone or in combination with other projects or plans, will have adverse effects on the integrity of a Natura 2000 site, and includes any mitigation measures necessary to avoid, reduce or offset negative effects.

It is envisaged that there will be no significant adverse effects on the integrity of the Mullet/Blacksod Bay SAC or Blacksod Bay/Broad Haven SPA in view of these site’s conservation objectives and that the conservation status of the Annex I habitats, Annex II species or Special Conservation Interests will not be compromised by WwTP discharge either directly, indirectly or cumulatively. This is subject to the implementation of an appropriate wastewater treatment system at Gweesalia to ensure improved effluent quality, and to continued monitoring of the plant performance and effluent.

It is therefore concluded that the Gweesalia WwTP discharge, alone or in-combination with other plans and / or projects will not give rise to significant effects on the integrity of the Mullet/Blacksod Bay SAC and Blacksod Bay/Broad Haven SPA. Stage 2 concludes the Appropriate Assessment process of the Gweesalia Waste Water Certificate of Authorisation.

References

NPWS (2014a) Conservation Objectives: Mullet/Blacksod Bay Complex SAC 000470. Version 1. National Parks and Wildlife Service, Department of Arts, Heritage and the Gaeltacht.

NPWS (2014b) Conservation Objectives: Blacksod Bay/Broad Haven SPA 004037. Version 1. National Parks and Wildlife Service, Department of Arts, Heritage and the Gaeltacht.

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NPWS (2014c) Blacksod Bay/ Broad Haven Special Protection Area (Site Code 4037). Conservation Objectives Supporting Document. Version 1. National Parks and Wildlife Service. November 2014.

OECD (1986) Water pollution by fertilisers and pesticides. Organisation for Economic Cooperation and Development, Paris, 144 pp.

Routledge, E.J., D. Sheahan, C. Desbrow, G. Brighty, M. Waldock, and J.P. Sumpter (1998). Identification of estrogenic chemicals in sewage treatment effluent, 2. In vivo responses in trout and roach, Environment, Science and Technology, 32: 1559-65.

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