portlaoise waste water treatmthe site synopsis for the affected sac is included as appendix i to...

Portlaoise Waste Water Treatm

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River Barrow and River Nore Special Phrealof Conservatio (site code 002162)

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I Appropriate Assessment I

Prepared on behalf of

WATER SERVICES LAOIS COUNTY COUNCIL

County Hall Portlaoise Co. Laois

REPORT VERSION: 31'' October 2008

Environmental qrotection Agency Received

ENVI RUWt4;EPI TAL CWSLELTAtSTS Tait Business Centre, Dominic Street, Limerick City, Ireland.

t. +353 61 313519, f. +353 61 414315 e. [email protected] w. www.ecofact.ie

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Portlaoise WwTP Appropriate Assessment

TABLE OF CONTENTS

1 . INTRODUCTION ............................................................................................................... 3

1 . 1 LEGISIATIVE CONTEXT .................................................................................................. 3 2 . METHODOLOGY .............................................................................................................. 5

2.1 DESKTOP REVIEW ......................................................................................................... 5 2.2 FIELD SURVEY .............................................................................................................. 5 2.3 ASSESSMENT METHODOLOGY ....................................................................................... 6

STAGE 1 : SCREENING I TEST OF SIGNIFICANCE ...................................................... 8

3.1 ASSESSMENT CRITERIA ....................................................................................................... 8 3.1 DESCRIPTION OF THE RECEIVING ENVIRONMENT ............................................................. 9

3.1.1 Introduction ............................................................................................................... 9 4.1.2 The River Barrow and River Nore SAC .................................................................... 9 4.1.3 River Barrow catchment ........................................................................................... 9

3.1.1 Introduction ............................................................................................................. 11 3.1.2 Process Description ......................................................................................... 12 3.1.4 Receiving Water Quality ................................................................................... 13 3.1.4 Waste Water Emissions ................................................................................... 16

DESCRIPTION OF EFFECTS AND POTENTIAL EFFECTS ..................................................... 18 4.2.1 Direct impacts ................................................................................................... 18 4.2.2 Indirect impacts ................................................................................................. 18 4.1.2 Cumulative impacts .......................................................................................... 18

5 . STAGE 2: APPROPRIATE ASSESSMENT .................................................................. 19

3 .

3.1 DESCRIPTION OF THE PROJECT .................................................................................... 11

4.2

4.3 SIGNIFICANCE OF EFFECTS .......................................................................................... 19

5.1 5.2 5.3

5.4

DESCRIPTION OF NATURA 2000 SITE AFFECTED .......................................................... 19 DESCRIPTION OF HABITATS IN THE AFFECTED AREA OF SAC ......................................... 19 DESCRIPTION OF WILDLIFE IN THE AFFECTED AREA OF SAC .......................................... 19

CONSERVATION OBJECTIVES FOR RIVER BARROW AND RIVER NORE CSAC .................. 23

IMPACT PREDICTION I ASSESSMENT .................................................................... 23

5.5.1 Introduction ............................................................................................................. 23 5.5.2 Impact of the existing plant ..................................................................................... 26 5.5.3 Impact of the new plant .......................................................................................... 28

6 . STAGE 3: ASSESSMENT OF ALTERNATIVE SOLUTIONS ........................................ 32

7 . STAGE 4: ASSESSMENT WHERE ADVERSE IMPACTS REMAIN ............................. 32

8 . CONCLUSION ................................................................................................................. 33

REFERENCES ......................................................................................................................... 34

PLATES ................................................................................................................................... 37

APPENDIX 1 NPWS SITE SYNOPSOS .................................................................................... 40

APPENDIX 2 WATER QUALITY MONITORING DATA ......................................................... 45

APPENDIX 3 BIOLOGICAL WATER QUALITY MONITORING SEPTEMBER 2008 ............ 51

APPENDIX 4 ASSESSMENT OF IMIPACTS AND IMPACT SIGNIFICANCE ........................ 54

5.3.1 Aquatic ecological assessment (September 2008) .......................................... 20

5.5

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1. INTRODUCTION

The current document assesses the likely significant effects of the existing and proposed Portlaoise Waste Water Treatment Plant (WwTP) discharges upon the Barrow and Nore Special Area of Conservation (SAC). Effects upon both habitats and species within the SAC are considered. The Portlaoise WwTP does not discharge directly into the SAC so would not be having any direct effects on this area. The boundary of the SAC is located approximately 1 Okm downstream of the discharge point on the River Triogue. Only the section of the Triogue River immediately upstream of the River Barrow confluence is included in the SAC.

Presently, the Portlaoise WWTP is undergoing a major investment programme. This involves the replacement of much of the existing treatment works with totally new facilities, on the existing site. The new plant is scheduled to be commissioned in January 2009, and began to partially operate at the time of preparing the current report. Because of the short timescale between this commissioning and the present licence application date, it was agreed with the Environmental Protection Agency to apply for a discharge licence in respect of both plants in the same application. Likewise, the current document also assesses the discharge from both the existing and proposed facilities.

This document draws upon the information presented in the following reports-

0 MCOS/COWI (2001 ) Portlaoise Main Drainage: Environmental Impact Statement (EIS) for the Upgrade of Portlaoise Wastewater Treatment Works. August 2001. Laois County Council.

0 MCOS/COWI (2000) Portlaoise Main Drainage Preliminary Report. Technical Report Number 1 . Portlaoise Waste Water Treatment Works Receiving water Assessment. Laois County Council.

A range of other sources of information provided by Laois County Council were utilised in this assessment. Likewise, additional sources of information including scientific reports produced by, and information on the websites of the EPA, NPWS, Laois County Council and other agencies were also reviewed.

The site synopsis for the affected SAC is included as Appendix I to this report. The current report was prepared by Ecofact Environmental Consultants Ltd. on behalf of Laois County Council during September 2008.

1 .I Legislative context

Council Directive 92/43/EEC on the conservation of natural habitats and of wild fauna and flora - ‘The Habitats Directive’, has been transposed into Irish law by The European Community (Natural Habitats) Regulations 1997 (S.I. No. 94/1997).

The 1997 Regulations were updated in 1998 by The European Communities (Natural Habitats) (Amendment) Regulations. 1998 (S.I. No. 233/1998) to include Council Directive 97/62/EC which served to update Council Directive 92/43/EEC, adapting it to technical and scientific progress made in the intervening years.

The 1997 Regulations were again updated in 2005, by The European Communities (Natural Habitats) (Amendment) Regulations 2005 (S.I. No. 378/2005). This amendment served to consolidate the main nature conservation legislation enacted in Ireland, meaning The Wildlife Act 1976, The Wildlife (Amendment) Act 2000, The European Communities (Natural Habitats) Regulations 1997, The European Communities (Natural Habitats) (Amendment) Regulations 1998, and to draw direct reference upon Council Directive 79/409/EC on the conservation of wild birds - ‘The Birds Directive’.

The Birds Directive seeks to protect birds of special importance by the designation of Special Protection Areas (SPAS) whereas the Habitats Directive does the same for habitats and other

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species groups with Special Areas of Conservation (SACs). It lists certain rare habitats (Annex I) and species (Annex II) whose conservation is of community interest. It is the responsibility of each member state to designate SPAS and SACs, both of which will form part of Natura 2000, a network of protected areas throughout the European Community.

Article 6, paragraphs 3 and 4 of the Habitats Directive state that:

6(3) 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 for the site in view of the site's conservation objectives. In the 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.

6(4) If, in spite of a negative assessment of the implications for the 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, the Member State 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.

Where the site concerned hosts a priority natural habitat type and/or a priority species, the only considerations which may be raised are those relating to human health or public safety, to beneficial consequences of primary importance for the environment or, further to an opinion from the Commission, to other imperative reasons of overriding public interest.

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2. METHODOLOGY

Barrow Triogue confluence : NOS Grid Reference N47368 09769

2.1 Desktop Review

downstream of the Barrow Triogue confluence N47563 09832

A review of areas designated (or being considered for designation) for nature conservation was carried out by consulting the National Parks and Wildlife Service (NPWS). These included Special Areas of Conservation, Special Protection Areas for birds (both internationally important) and proposed Natural Heritage Areas (of national importance). Technical files and previous reports prepared for the WwTP were supplied by Laois County Council for review in the current assessment. These reports included the catchment report for Portlaoise town, prepared as part of the National Urban Waste Water Study, and the Environmental Impact Statement for new plant. In addition, monitoring information on the discharges from the WwTP and the receiving waters were obtained from Laois County Council and used in this assessment. A review of the published literature, including the Laois County Development Plan 2006-2012, was undertaken in order to collate data on the receiving environment, including aquatic species and habitats of conservation concern in the study area. A range of additional sources of information including scientific reports produced by, and information on the websites of the EPA, NPWS, Laois County Council and other agencies were also reviewed. A full bibliography of information sources reviewed is given in the references section. Ordinance Survey Maps and OS aerial photographs were also reviewed during the desk assessment.

2.2 Field Survey

The field survey comprised a systernatic walk over of the WwTP site, outfalls, and receiving waters. A kick sampling assessment of benthic macro-invertebrates was undertaken a point located upstream (control) and downstream (receptor) of the River Triogue confluence with the River Barrow SAC to supplement information collected during the desk study. The exact location and description of these sites is provided in Table 1. It is noted that water quality in the River Triogue at this point would be influenced from inputs other than the Portlaoise WwTP.

Table 1 Location of the 2008 survey sites on RiversLBarrow.

Specimens were identified using the standard keys which are listed in the bibliography section. The abundances of organisms present was assessed as follows: Present (1 or 2 individuals), ScarcelFew (e1 %), Small Numbers (e%), Fair Numbers (5-1 O%), Common (1 0- 20%), Numerous (25-50%), Dominant (50-75%) and Excessive (>75%).

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I

The Quality Rating (Q) System (Toner et a/, 2005) was used to obtain a water quality rating for each site. The use of this particular biotic index allows for comparison with data published by the EPA. This method categorizes invertebrates into one of five groups, depending on their sensitivity to pollution. The higher the biological diversity and the greater the abundance of invertebrate species sensitive to organic pollution, the higher the water quality is assumed to be, and the higher the ‘Q value’ assigned to that sampling station. The revised BMWP scheme (Walley and Hawkes, 1997) is another biotic index of water quality that was used in the current appraisal. In this system, each family recorded in the sample is assigned a habitat specific score. This score depends on the pollution sensitivity of the invertebrate family together with the characteristics of the site where the invertebrates were found. A higher BMWP score is considered to reflect a better water quality and a score over 100 is indicative of very good water quality.

2.3 Assessment Methodology

The Department of the Environment, Heritage and Local Government has not published guidelines for undertaking Appropriate Assessment in Ireland. This Appropriate Assessment has been carried out using the following guidance:

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 2000);

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, Office for Official Publications of the European Communities, Luxembourg (EC 2001); The Habitats Regulations: A guide for competent authorities, Environment and Heritage Service, Belfast (EHS, 2002);

Guidance for Competent Authorities when dealing with proposals affecting SAC freshwater sites, Scottish Natural Heritage, Perth (SNH, 2006); and

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).

Based on these guidelines, the assessment is a four staged approach described below and illustrated in Figure 1.

Stage One: Screening / Test of Significance - the process which identifies the likely impacts upon a Natura 2000 site of a project or plan, either alone or in combination with other projects or plans, and considers whether these impacts are likely to be significant;

Stage Two: Appropriate Assessment - the consideration of the impact of the project or plan on the integrity of the Natura 2000 site, either alone or in combination with other projects or plans, with respect to the site’s s.tructure and function and its conservation objectives. Additionally, where there are adverse impacts, an assessment of the potential mitigation of those impacts;

Stage Three: Assessment of Alternative Solutions - the process which examines alternative ways of achieving the objectives of the project or plan that avoid adverse impacts on the integrity of the Natura 2000 site; and

Stage Four: 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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I IUn Yes

A Is the PP likely to have significant effects on the site? 1.1

Yes - Nn

I I-- Yes

Redraft the PP -1 I I

Nn

1 Does the site host a pnority habitat or species7 I(

No

Yes

1 Are there imperative Are there human health or reasons of overriding safety considerations or public interest? important environmental

benefits?

I I I No Nn Yes

Y er , -I

1 Authonsatron mus!

( 1

1

gure 1 Flowchart outlining the appropriate assessment process (Adapted from EC, 2001).

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3. STAGE I : SCREENING I TEST OF SIGNIFICANCE

This stage examines whether or not likely effects upon a Natura 2000 site will be significant.

The screening process in this report follows the matrix outlined in the EC Environment DG (2001) report. The headings to be covered by this matrix are outlined below and are discussed further in the following text.

0

0

Brief description of the project or plan. Brief description of the Natura 2000 site.

3.1 Assessment criteria

Describe the individual elements of the project (either alone or in combination with other plans or projects) likely to give rise to impacts on the Natura 2000 site.

Describe any likely direct, indirect or secondary impacts of the project (either alone or in combination with other plans or projects) on the Natura 2000 site by virtue of:

size and scale; land-take; distance from the Natura 2000 site or key features of the site; resource requirements (water abstraction etc.); emissions (disposal to land, water or air); excavation requirements; transportation requirements; duration of construction, operation, decommissioning, etc.; other.

Describe any likely changes to the site arising as a result of: reduction of habitat area:

0 disturbance to key species; 0 habitat or species fragmentation; 0 reduction in species density; 0

climate change. changes in key indicators of conservation value (water quality etc.);

Describe any likely impacts on the Natura 2000 site as a whole in terms of:

0

0

interference with the key relationships that define the structure of the site; interference with key relationships that define the function of the site.

Provide indicators of significance as a result of the identification of effects set out above in terms of:

loss; 0 fragmentation;

disruption; 0 disturbance; 0 change to key elements of the site (e.g. water quality etc.).

Describe from the above those elements of the project or plan, or combination of elements, where the above impacts are likely to be significant or where the scale or magnitude of impacts is not known.

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3.1 Description of the receiving environment

3. I. 1 Introduction

The Portlaoise WwTP discharges into the Triogue River, a tributary of the River Barrow. The River Triogue joins the River Barrow approximately I Okm downstream of the ,WwTP outfall. The lower reaches of the River Triogue are included within the ‘River Barrow and River Nore’ Special Area of Conservation’ (site code 002162) for a short distance upstream of the Barrow confluence. No other Natura 2000 sites would be affected by the existing or proposed discharge.

4.1.2 The River Barrow and River Nore SAC

The ‘River Barrow and River Nore’ Special Area of Conservation (site code 002162) is selected for alluvial wet woodlands and petrifying springs, priority habitats on Annex I of the E.U. Habitats Directive, 1992. The site is also selected as a SAC for old oak woodlands, floating river vegetation, estuary, tidal mudflats, Salicornia mudflats, Atlantic salt meadows, Mediterranean salt meadows, dry heath and eutrophic tall herbs, all habitats listed on Annex I of the E.U. Habitats Directive.

As well as habitats, the SAC has been selected due to the presence of invertebrate, fish and mammal species which are listed under Annex II of the EU Habitats Directive, including freshwater pearl mussel (Margaritifera margaritifera and its hardwater form M. m. durrovensis), freshwater crayfish (Austropotamobius pa//ipes), Atlantic salmon (Salmo salar), twaite shad (Alosa fallax fallax), the three Irish Lamprey species - sea (Petromyzon marinus), brook (Lampetra planer0 and river (Lampetra fluviatilis), the Desmoulin’s whorl snail Vertigo moulinsiana and Eurasian otter (Lutra lutra). The Barrow is one of only a handful of spawning grounds in the country for twaite shad, and is the most important site for this species. Other important animal species are also found in the Barrow/Nore SAC. These include Daubenton’s bat (Myotis daubentono, badger (Meles meles), Irish hare (Lepus timidus hibernicus) and frog (Rana temporaria), all species listed in the Irish Red Data Book. The rare Red Data Book fish species smelt (Osmerus eperlanus) occurs in the estuary. Two other freshwater mussel species, Anodonta anatina and A. cygnea are also found in the Barrow (Lucey, 1998).

4. I . 3 River Barrow catchment

The River Barrow (EPA code 14/B/01) is 192 kilometers long and drains a catchment of approximately 2983 km2. The River Barrow has the second longest main river channel in the country, after the River Shannon. It rises in the Slieve Bloom Mountains in County Laois approximately 6 km south of Clonaslee. It flows north easterly until it reaches the Offaly county boundary at Monettia Bog where it turns in a south easterly direction. From near Mountmellick, it flows in an easterly direction through Mountmellick forming part of the boundary between Laois and Offaly, to Monasterevin. From Monasterevin the river flows in a southerly direction through Athy, Carlow, Leighlinbridge, Bagenalstown, Grauigenamangh and New Ross, to its confluence with the River Suir at Cheekpoint. The Barrow is joined by the Nore approximately 4 km upstream of New Ross and is tidal for another 13 km upstream to St. Mullins.

From Monasterevin to Carlow, the channel flows over limestone and lies in an open landscape. However, the channel is bounded closely to the west by the Castlecomer Plateau from Carlow south to Goresbridge. The topography is further altered dramatically to the south of Goresbridge as the geology changes from limestone and the Barrow incises its way through a narrow gorge cut between the granite of the Blackstairs Mountains, immediately to the east, and the Brandon Hill granite, which dominates the landscape to the west (King, 2006).

The overlying soils in the Barrow catchment reflect, in large measure, the underlying geology. The highlands of the Slieve Blooms consist of blanket peat and peaty gleys of sandstone origin (King, 2006). These give way to gleys of limestone origin or to river alluvium in the

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catchment downstream to Monasterevin. The extensive area drained by the Slate and Figile systems, entering the main Barrow at Monasterevin, has soils of basin peat and of podzolics of limestone origin. From Monasterevin to Goresbridge, the principal soil association is one of grey brown podzolics, all of limestone origin. In the area between Athy and Goresbridge a narrow ribbon of soils is composed of morainic gravels and sands and these materials are extensively quarried in surface excavations. As with the geological changes at Goresbridge, so the soils also change and have their origins in granitic or Silurian glacial till or shales. The soil types from Athy down to the confluence with the R. Suir are all identified as excellent for tillage, with good sheep grazing soils on the granitic glacial tills.

Major commercial peat workings have been developed in the lowland areas to the north of the Slieve Blooms, around Mountmellick and in the catchments of the Slate and Figile to the north of Monasterevin. South of Monasterevin, extensive areas of good farmland occur, both on low and on elevated ground. Grassland for grazing and silage production are common as is tillage production. Cereals and root crops were traditionally grown to service major brewing and sugar-beet production in Kilkenny and Carlow respectively.

The river falls steeply in its upper reaches, dropping 400m over an initial channel length of 10 km. The high mean gradient value of 4% gives way to mean values of 0.06% between Two- Mile Bridge and Monasterevin and a value of 0.02% from Monasterevin to Athy (King, 2006). Such low gradient values are indicative of a slow-flowing channel with predominance of deep, pool-type habitat or of continuous, deep glide habitat.

The main tributaries joining the left bank (east side) are the Cushina, Figile and Slate which form one tributary at Monasterevin and the Tully, Greese, Lerr, Burren, Mountain and Poulmounty, while on the right bank (west side) it is joined by the Owenass, Triogue, Stradbally, Douglas, Fushogue, Gowran, Powerstown and Duiske tributaries.

The River Barrow has been the sutiject of an arterial drainage scheme (1926 - 1934) with 210 km of main rivers and tributaries and 175 km of smaller drains deepened and widened, to improve conveyance, in the course of the works programme (King, 2006). The extent of the drainage programme was largely confined to the catchment upstream of Athy. The drainage scheme identified the natural division of the catchment between the extensive areas of flat land upriver of Athy and the narrower, corridor-like character from Athy down to St. Mullins. The scheme as executed is currently maintained by the Barrow Drainage Board, composed of the three counties of Laois, Offaly and Kildare. Management involves retaining the channel conveyance as excavated in the original scheme. This process involves in-channel work, including removal of sediment deposits, fallen trees and other physical obstructions to passage of flood flow, and management of bank slopes to retain stability.

To accommodate navigation, as well as providing hydropower to a number of industrial units, the River Barrow was regulated by a number of major weirs, creating a series of very low gradient reaches between each weir. Navigation at each weir was accommodated through a network of lock gates. The navigation system is currently managed by Waterways Ireland. Downstream of Athy, the Grand Canal - Barrow Line navigation switches from being an exclusively canal-like channel to one where navigation takes place within the riverine channel. The Barrow in conjunction with stretches of the canal, provides a navigable channel between New Ross and the main Grand Canal system at Athy. The navigation system is currently managed by Waterways Ireland. Their programme of management includes maintenance of the navigation channel within the River Barrow’s cross-section, a process that can require the removal of silt deposition and in channel growths of tall emergent vegetation. The tributary channels, as with the main stem, derive their character from local topography, geology, soil and land use.

Most of the main channel of the River Barrow and its main tributaries are part of the Barrow/Nore Special Area of Conservation (SAC) which is designated under the Habitats Directive as having special conservation value because of the presence of listed species and habitats.

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‘1 Portlaoise WwTP Appropriate Assessment

4.1.3.1 River Trioclue

The Triogue River (EPA code 14iT/01) is a third order tributary of the upper River barrow. It is approximately 23km long and drains a catchment area of 96 km2 (MCOS/COWl, 2001). Flow rates at two points in the catchment area resented in Table 2. The flow rates in the River Barrow upstream (catchment area 276 km ) and downstream of the Triogue confluence are provided in Table 3 for comparison. It can be seen from this Table that despite its small catchment area the Triogue River has a larger flow that the Barrow at this point during 95%ile and 99%ile flows. This is because much of the upper Barrow catchment is composed of ‘spate’ streams which mainly derive their flows from surface runoff. The Triogue on the other hand derives much of its flows from groundwater inputs. Water quality in the Triogue therefore has a much greater influence on water quality in the Barrow main channel during normal and low flows than its catchment area would suggest.

5)

It rises in the townland of Ballygorrnhill South less than 6 km south east of Portlaoise and generally flows in a northerly direction until it meets the River Barrow. The confluence with the River Barrow is approximately 3 km northeast of Mountmellick, or over 1 km downstream of Borness Bridge on the River Barrow. The Triogue River has a low gradient and falls no more than 70 meters over its entire course. There is a small component of commercial forestry in the catchment but land use is mainly agricultural (Source: EPA Envision map). The Triogue River predominantly drains peaty gley and surface water gley soils and also some blanket peat. The underlying geology is of Carboniferous Limestone with a small proportion of Old Red Sandstone in the western part of the catchment (Source: GSI). For part of its course upstream of Portlaoise, the Triogue River is called the Cush River. This part of the river is fed mainly by drains, many being interlinked indicating the low lying nature of this area. Approximately 3 km upstream of Portlaoise, the river is called the Triogue by which time it is a third order river. Approximately one third of the Triogue catchment is above the town of Portlaoise. The Triogue River is bordered by Portlaoise town for more than 1.5 km. From Portlaoise to its confluence with the River Barrow, the River Triogue is fed by relatively short tributaries. In this stretch, the Triogue is crossed by seven bridges, the largest being the R422 Bridge or Triogue Bridge.

Under the Urban waste water treatment regulations (S.I. No. 254 of 2001), the Triogue has now been classified as a nutrient sensitive water downstream of the Portlaoise sewage outfall, to its confluence with the River Barrow

Table 2 River Triogue flow rates (taken from MCOS/COWI, 2000, and Laois County Council reports).

Table 3 Upper River Barrow flow rates (taken from MCOS/COWI, 2000).

3.1 Description of the project

3.1. I Introduction

The current project involves the discharge of treated sewage from the Portlaoise WwTP. The project includes the existing WwTP discharge and also a discharge a new plant under

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i Portlaoise WwTP Appropriate Assessment

construction at the site. The new plant is due to commence operation in January 2009, and was partially operating at the time of the current assessment. The Portlaoise WwTP is located to the north of the town off the Ridge road, adjacent to the River Triogue. It discharges to the River Triogue downstream of Portlaoise. The Triogue in turn discharges into the River Barrow, about 12 km further downstream. The River Barrow is part of the River Barrow and River Nore Special Area of Conservation (SAC).

The River Triogue is approximately 23 km long and drains a catchment area of approximately 96 km2. The Triogue is a relatively small river and does not have a large assimilative capacity to accept pollutant load. Its ability to assimilate wastes has been further reduced by increased background pollution since the 1980’s. The source of this pollution is unknown but is likely to include inputs from agricultural activities and poorly performing septic tanks in the catchment. The Triogue River was designated a Nutrient Sensitive Water Body in 2001 (MCOSICOWI, 2001).

The existing Portlaoise WwTP has been in continuous use since 1980 and has undergone several upgrades. It consists of preliminary treatment feeding and secondary biological treatment. There are two independent secondary systems in operation. These are an Extended Aeration plant and a Rotary Biological Contactor. A sludge dewatering plant is also present. The new plant is presently under construction at the existing WwTP site. The design is to cater for a pe of 39,000 and has allowed for the relatively small size of the receiving water, the Triogue River. In addition to secondary treatment there will be nutrient removal, both phosphorus and nitrogen, and also tertiary filters and a re-aeration system.

The Portlaoise main drainage catchment comprises the older town centre area, the newer outlying suburbs and a considerable area of land which has been zoned for development in the current County Development Plan. The sewer network generally comprises of combined systems in the older town area, with segregated systems in the newer outlying suburbs. Because of the relatively flat nature of the catchment, a large portion of the catchment is served by pumping stations.

3.7.2 Process Description

3.1.2.1 Existins System I

The inlet works at the existing Portlaoise WwTP consist of preliminary treatment and stormwater overflows. The stormwater buffer tank consists of a rectangular storage tank with transfer pumps. This returns the flow to the works as capacity arises. It is designed with an overflow pipe directly to the river. In very strong flows, the inlet can be bypassed directly to the river with only coarse screening. The inlet collection chamber is fed from three gravity sewers. This feeds through a coarse screen removal system and two vortex grit removal tanks. These feed into a collection chamber with two Archimedean screw pumps. These pumps control the flow of wastewater into the biological treatment systems. They pump into a stilling station from which the flow is divided between a Package Treatment system (RBC’s) and an Extended Aeration system.

The Package Treatment system is i i Stahlermatic and has a design capacity of 5,000 PE. It consists of 2 banks of 3 in-line Rotating Biological Contactors. This feeds into 2 settling tanks from which liquid is fed either back to the RBC’S or to final effluent. Waste sludge is fed to a sludge holding sump which in turn feeds to the main sludge settling tank.

The Extended Aeration system consists of 2 aeration tanks using diffused aeration blowers. These feed into the clarifier or settling tank. Activated sludge is returned from the base of the clarifier back to the aeration tanks arid clarified effluent overflows the weir at the top. Clarified effluent from both systems combines before feeding directly into the Triogue River.

Waste sludge from both systems first passes into a sludge settling tank and then onto a centrifuge dewatering unit. It is immediately stabilised with lime prior to removal from site by a licensed contractor, for land spreading. All sludge liquors are returned to the aeration tanks.

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The extended aeration tanks are designed to allow time for nitrification to take place. Phosphorus removal is by Aluminium Chloride dosing prior to the settling tanks.

3.1.2.2 New Dlant

This upgraded system is scheduled to replace the existing plant in January 2009, and this process had begun at the time of visiting the plant during early October 2008.

Inlet flows will be pumped to the inlet works situated above ground. A Combined Inlet System will be used where screening and grit removal are in a single tank. Screens will remove gross solids greater than 6mm. Storm flows will be separated after the screening and grit tank and will be diverted to a new storm tank. The existing storm tank will also be used but the system design will normally only allow overflows from the new tank. However, in emergency situations an overflow will occur directly from the existing tank.The biological treatment process in the new plant will follow the same principle as for the existing extended aeration system, i.e. activated sludge, with some modifications. The new system is based on the use of anoxic tanks, aeration tanks and final settlement tanks. The influent will feed into the anoxic tanks where it will mix with mixed liquor returned from the aeration tanks. This recirculation will allow denitrification to take place thereby reducing nitrate levels. Activated sludge will also be returned to the anoxic tanks from the settlement tanks. The anoxic tank will feeds into the aeration tanks which in turn will flow into the settlement tanks. Waste sludge will be drawn off from the settlement tank. Flows from the settlement tanks will pass through a tertiary treatment filter to further reduce suspended solids. The effluent will then passes through a re- aeration system before entering the outfall to the Triogue River. This will ensures that oxygen levels in the receiving waters are not adversely affected. Phosphate removal will be by aluminium chloride dosing. This will occur at the outlet from the anoxic tanks.

3.1.4 Receiving Water Quality

3.1.4.1 Background water qualitv in the River Trionue

In addition to water quality results presented in this section, supplementary water quality monitoring data for the Triogue and Barrow Rivers is also provided in Appendix II. Background water quality in the River Triogue has shown a marked decline upstream of Portlaoise town since the EPA (and their predecessors) began monitoring the river in the 1970’s. According to Clabby et a/ (2003) the station 1.6 km upstream of Portlaoise (0100) was rated as ‘Unpolluted (Q5)’ in the 1970’s. It maintained at least a Q4 status up until 1997. Since that time, the water quality here has gradually declined to ‘Moderately Polluted (Q3)’ in 2006 (Neill, 2007). This trend was also observed in the other station upstream of Portlaoise (Cush Bridge, station No. 0600). The biological water quality results for the River Triogue upstream of Portlaoise from 1971 to 2006 are presented in Table 4. Laois County Council chemical water quality results for the period November 2006 to September 2007 from the River Triogue upstream of the Portlaoise WwTP outfall are summarized in Table 5. The mean background level of orthophosphate measured during this period was 0.06 mgll with a maximum value of 0.21 mg/l. Based on the EPA data provided in Neill (2006) and (2007) (see Appendix I I ) the mean background level of orthophosphate during the EPA sampling period was 0.04 mg/l. Orthophosphate levels of 0.03 mg/l or less are required to maintain healthy salmonid populations (EPA, 2001). These chemical results demonstrate that the Triogue River has no assimilation capacity for Ortho-phosphate and this is reflected in the biological water quality of the river.

3.1.4.2 Background water qualitv in the River Barrow

The nearest EPA station on the River Barrow upstream of the Triogue confluence is located just over 1 km upstream of where the two rivers join (Station No. 0500 at Barranagh’dBorness Bridge). This station is located less than 300 meters downstream of the Owenass River confluence, which is the receptor of treated sewage from Mountmellick. Between 1980 and 1989, this station was rated as being ‘Unpolluted (Q4)’. During the period

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1974 1978 1980

1993 to 2003, water quality at Borness Bridge was rated as 'Slightly Polluted (Q3-4)'. This rating of Q3-4 was also given in 2006 (Neill, 2007). The biological water quality results for the River Barrow site upstream of the Triogue confluence from 1971 to 2006 are presented in Table 6. Table 7 shows the chemical water quality results from Neill (2007) at a site located 1 km upstream of the Triogke River confluence. At this location mean Orthophosphate concentrations for seven samples was 0.09mgll so exceeded limit values (0.03mgll).

4 4-5 4

Table 4 River Triogue (EPA code 14Fr/01) Biological Quality Ratings (Q values) from the two sites monitored by the EPA upstream of Portlaoise, adapted from Clabby et a/, 2004) and Neill (2007). Unsatisfactory ratings are highlighted in bold (see Toner et a/, 2005).

1984 1986 1989 3

4 4-5 4

i" 2006

1993 1 3 14 1997 13 14

3-4 3 3

Table 5 River Triogue (EPA code 14/1701) chemical water quality results for the period November 2006 to September 2007 (summary of Laois County Council monitoring data).

Table 6 River Barrow (EPA code 14/8/01) Biological Quality Ratings (Q values) from site 0500 located 1 km upstream of the Triogue River confluence, adapted from Clabby et a/, 2004) and Neill (2007). Unsatisfactory ratings are highlighted in bold (see Toner et a/, 2005).

Table 7 River Barrow (EPA code 14/B/0'1) chemical water quality results for 2006 from site 0500 located 1 km upstream of the Triogue River confluence, adapted from Neill (2007). Values considered to be elevated are highlighted in bold (as per criteria in EPA, 2001).

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3.1.4.3 Assimilation capacities

limit Background concentration (mg/l) Assimilation capacity (mg/l) Assimilation capacity (Kg of parameter /day)

The assimilation capacity of the River Triogue and Barrow for key water quality parameters is provided in Tables 8 and 9 respectively.

1.7 0.04 (EPA data) 3.67 0.06 (Laois Coco)

1.3 0.01 (EPA data) None

10.1 0.078 (EPA data) None 0.01 (Laois Coco)

0.233 (Laois Coco)

The Phosphorus Regulations (S.I. No. 258 of 1998) specified that the rivers with a Q2 should achieve a minimum target of Q3 by the year 2007, which correspond to a median of 0.07mg/l of Molybdate-Reactive Phosphate (MRP). The Third Schedule of the Phosphorous Regulations (SI. No. 258 of 1998) requires that the existing water quality of the Triogue and the Barrow must be upgraded from a biological quality rating of Q2 and Q3-4 to Q3 and Q4 respectively. Therefore the target orthophosphate value for 2007 for the Triogue and Barrow Rivers was 0.07 mg/l (Moderately-Seriously Polluted) and 0.03 mg/l (Slightly Polluted) respectively. After 2007, the required Q rating for all Irish Rivers should ideally be Q4 which relates to an orthophosphate concentration of 0.03 mg/l. MCOS/COWI (2000) noted that a minimum of "Q3-4 would be required to protect salmonid fish in the Triogue". This would equate to a target annual median orthophosphate level of 0.03 mg/l. However, it is noted that with a background mean orthophosphate level of 0.06 mg/l (range 0.03 to 0.21 mg/l, November 2006 to September 2007) this would be impossible to attain at present as the background level itself is in significant breach of these standards. Achievement of the Phosphorous Regulations standard was considered at the time of preparing the Environmental Impact Statement for the new Portlaoise WwTP scheme to be below the practical limits, which could be achieved by proven available technologies, given the background concentrations of phosphorous in the River Triogue. In the EIS it was commented that "it may be possible to reduce the background concentration by implementing an integrated nutrient management approach for agriculture in the upstream catchment. However, reduction of the background concentration is outside the scope of this EIS'.

0.03**

None

None

Table 8 Assimilation capacity of the Triogue River for selected parameters upstream of the Portlaoise WwTP discharge. Based on a 95%ile flow of 0.09m3/s for the Triogue River at the discharge point. Note that a river will be at 95%ile flow or lower only 5% of the time. For the rest of this time significantly greater dilution will be available.

IO* 0.15**

15 None

116.6 none

Parameter

Parameter 0.07 0.01 25 0.1

'This represents a 'moderately to seriously polluted' limit value. Essentially there is no assimilation capacity for this parameter.

Background concentrations are based on Laois County Council monitoring data during the period November 2006 to September 2007 except the following:- * An estimated background level of IOmgA was used for Suspended Solids. ** From Neill, 2007 and Neill, 2008 (average value from station 0160 u/s Portlaoise WwTP discharge; N=4 in 2006, N=l in 2007).

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Table 9 Assimilation capacity of the River Barrow for selected parameters upstream of the Triogue River confluence. Based on a 95%ile flow of 0.216m3/s for the River Barrow at Borness Bridge, EPA background concentrations and parameter limits. Note that a river will be at 95%ile flow or lower only 5% of the time. For the rest of this time significantly greater dilution will be available.

Orthophosphate

Parameter limit

Nitrate Nitrite Suspended Ammonia (mgll N) (mgll Solids (mgll N)

N) (mgW

2 0.01 25 0.1

Background concentration (mgll)

None Assimilation capacity (mg/l)

2.01 .026 I O * 0.1 1

None None 15 None

Assimilation capacity (Kg of parameter /day)

None None 283.8 none

*An estimated background level of IOmgA was used for Suspended Solids.

3.1.4 Waste Water Emissions

The requirements of Urban Wastewater Treatment Directive 9112711EEC for treatment plants serving a population equivalent of more than 2000 are:

0 Biochemical Oxygen Demand (BOD5) 25mg/l O2 0 Chemical Oxygen Demand 125mg/l O2 0 Suspended Solids (p.e. >IO 000) 35mg/l 0 Suspended Solids (p.e. 2000 - 10 000) 60mg/l

The following additional requirements apply for discharges to areas that are deemed to be sensitive:

0 Total Phosphorus (IO 000 - 100 000 p.e.) 2mg/l 0 Total Phosphorus (over 100 000 p.e.) 1 mg/l 0 Total Nitrogen (10 000 - 100 000 p.e.) 15mg/l 0 Total Nitrogen (over 100 000 p.e.) 1 Omg/l

3.1.4.1 Existing plant

Table 10 provides a description of the water quality characteristics of 'the existing WwTP discharge into the River Triogue. 'This data is derived from 2007 Laois County Council monitoring data and also from on-site laboratory results made by the plant operator (Earthtech). The plant is currently discharging below the levels required by the Urban Wastewater Treatment Directive. Currently operations in the plant are in transition from using the infrastructure of the old plant to that of the new plant.

3.1.4.2 New plant

Table 11 provides a prediction of the expected water quality characteristics for the new WwTP discharge into the River Triogue. These figures were derived by Laois County Council from the data for the Existing plant except for Total Phosphorous, Suspended Solids, Ammonia, BOD, and Total Nitrogen which are the design standards for the New plant. Orthophosphate which is an interim prediction of likely Orthophosphate levels based on a ratio between Total

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Phosphate and Orthophosphate in the existing effluent. A ratio of 0.61:l was established by Laois County Council to quantify the proportional amount of Orthophosphate relative to the amount of Total Phosphorus based on the results in Table 12. This ratio for the existing plant (based on three readings) has been assumed to be unchanged for the new plant for the purposes of the current report and in advance of further monitoring. A design level of 0.35mg/l for Total Phosphate is specified in the new plant design. Therefore using the above ratio calculation the orthophosphate level for the new plant discharge has been estimated as being 0.21mg/l by Laois County Council. In Tables 13 and 14 the percentage reduction for Total Phosphorus and Total Nitrogen predicted for existing and new plants is given (Source: Laois County Council). The new plant will provide a 94% reduction in Total Phosphorous and a 59% in Total Nitrogen.

, u r n Standards % ,

Table 10 Summary of water quality results for the outfall from Portlaoise WwTP during 2007. Data is from Laois County Council Monitoring data, along with on-site laboratory results.

Max. daily average kglday

35

Biochemical Oxygen Demand 25

7.7 1268

31 186 9.5 57 9 54

125 15

Table 1 1 Summary of expected water quality for the outfall for the new Portlaoise WwTP from January 2008 onwards. These figures are derived from the figures for the Existing plant except for (1) Total Phosphorous, Suspended Solids, Ammonia, BOD, and Total Nitrogen which are the design standards for the New plant, and Orthophosphate which is an interim prediction of likely Orthophosphate levels (see Table 9).

55 330 14.4 86 1 .I 7 7.3 44

2.56 15.4 0.64 4 70.3 422

1 . < " I 1 .. - " 1 ' nH . . Electrical Conductivity (@25'C) (pscm-I) Suspended Solids (mgA) Ammonia (as N) (mg/l) 3.0 27 Biochemical Oxygen Demand 25 6.8 61.4

UWTD Max. daily average kglday !Standards

7 7

125 55 496 15 15 135

1 .I 10 7.3 66 0.35 23.10 0.21* 3.16 70.3 634

Table 12 Relationship (ratio 0:0.61) between orthophosphate and total phosphate in three water samples taken from the oufflow of the existing Portlaoise WwTP.

I Location I 28/03/08 , I 11/04/08 . . I 22/05/08 Orthophosphate I 0.64mg/l I 0.929mg/1 I 1.62mg/l Total Phosphorus I 1.35mg/l I 1.4mg/1 I 2.45mg/1

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Table 13 Percentage reduction for Total Phosphorus predicted for existing and new plant (Source Laois County Council).

Y I New Plant I 5.67 I 0.35

Table 14 Percentage reduction for Total Nitrogen predicted for existing and new plant (Source Laois County Council).

4.2 Description of effects and potential effects

This section provides a screening exercise to establish the likelihood of the effects and potential effects of the existing and new Portlaoise WwTP plant on the River Barrow SAC being significant. It must be noted that the existing plant was gradually being decommissioned at the time of the current assessment as components of the new treatment system were coming online. It is expected that the new WwTP will be fully operational by January 2009.

4.2. I Direct impacts

The existing and proposed discharges from the Portlaoise WwTP are not directly into the ‘River Barrow and River Nore’ Special Area of Conservation’ (site code 002162) or any other Natura 2000 site. Therefore there would be no direct effects on this SAC as a result of the current or proposed discharge.

4.2.2 lndirect impacts

lndirect (or secondary) impacts are defined as effects that are “caused by and result from the activity although they are later in time or further removed in distance, but still reasonably foreseeable” (Bowers-Marriott, 1997).

There is potential for indirect effects on the SAC (i.e. River Barrow and lower reaches of the Triogue River) as a result of the proposed and existing discharges from the Portlaoise WwTP. This is because effluents released from the plant and sewer network (i.e. storm water) have the potential to be carried downstream into the SAC area. Based on information available from the EIS for the proposed new plant, the EPA biological water quality monitoring programme and also Laois County Council monitoring data, the existing WwTP discharge is having a serious negative effect on the Triogue River.

Because of the poor assimilation capacity of the River Triogue and the limited dilution capacity and assimilation capacity of the River Barrow at the confluence of the two rivers it must be considered likely for the purposes of this screening exercise that the new plant would have the potential to have significant adverse effects on the River Barrow downstream of the Triogue River confluence.

Potential exists through the operation of the proposed WwTW that an accidental pollution episode may affect water quality in the receiving water and this could affect water quality in the downstream SAC. However, the risk of such an event occurring is extremely low in a modern well managed plant. The risk of such an event happening at the proposed WwTW would also be much lower than is currently the case.

4.1- 2 Cumulative impacts

Cumulative impacts or effects are changes in the environment that result from numerous human-induced, small-scale alterations. Cumulative impacts can be thought of as occurring

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through two main pathways: first; through persistent additions or losses of the same materials or resource, and second,-through the compounding effects as a result of the coming together of two or more effects (Bowers-Marriott, 1997).

The Triogue has a poor assimilation capacity due to its relatively small size, but also as a result of pollution inputs from other sources both upstream and downstream of the Portlaoise WwTP outfall. Water quality and assimilation capacity in the River Barrow is also influenced by inputs from other sources further upstream in the catchment from the Triogue confluence (i.e. Mountmellick WwTP discharge). Therefore it must again be considered that for the purposes of this screening exercise that the new plant would have the potential to have significant adverse effects on the River Barrow SAC downstream of the Triogue Rover confluence as a result of cumulative inputs from other sources.

4.3 Significance of effects

It is clear that due to its low assimilation capacity and small size, the Triogue River is likely to continue to convey unassimilated wastewater from the new plant downstream into the River Barrow SAC. As the River Barrow itself also has relatively low dilution capacity and is already suffering from pollution problems it must therefore be concluded that the discharge from the new Portlaoise WwTP has the potential to have significant -adverse effects on the River Barrow downstream of the Triogue confluence (i.e. within the River Barrow and River Nore SAC). This conclusion must be reached despite that fact the treated effluent would be of a much higher standard that the existing one and that the new plant would bring positive benefits over the “do nothing scenario”. The Appropriate Assessment process must therefore now proceed to Stage 2, where potential impacts will be discussed in a more comprehensive manner.

5. STAGE 2: APPROPRIATE ASSESSMENT

5.1 Description of Natura 2000 Site affected

The River Barrow and River Nore Special Area of Conservation (site code 002162) has already been described in general in Section 4.1.2 of this report. This site is selected for alluvial wet woodlands and petrifying springs, priority habitats on Annex I of the E.U. Habitats Directive, 1992. The site is also selected as a SAC for old oak woodlands, floating river vegetation, estuary, tidal mudflats, Salicornia mudflats, Atlantic salt meadows, Mediterranean salt meadows, dry heath and eutrophic tall herbs, all habitats listed on Annex I of the E.U. Habitats Directive. As well as habit:ats, the SAC has been selected due to the presence of invertebrate, fish and mammal species which are listed under Annex II of the EU Habitats Directive, including freshwater pearl’ mussel (Margaritifera margaritifera and its hardwater form M. rn. durrovensis), freshwater crayfish (Austropotarnobius pallipes), Atlantic salmon (Salmo salar), twaite shad (Alosa fallax fallax), the three Irish Lamprey species - sea (Pefrornyzon marinus), brook (Larnpefra planeri) and river (Larnpefra fluviafilis), the Desmoulin’s whorl snail Vertigo rnoulinsiana and Eurasian otter (Lutra lutra).

5.2 Description of habitats in the affected area of SAC

In Table 12 the qualifying interests for the River Barrow and River Nore SAC are listed, and it is indicated whether these habitats would be present in the upper River Barrow in the general vicinity of the Triogue River confluence. None of the habitats for which the SAC is designated for are thought to occur in the study area. Floating river vegetation is thought to be absent from the River Barrow in the areas irnmediately upstream and downstream of the study areas (i.e. to 5km) as a result of historical drainage operations. This habitat was not recorded during the current survey.

5.3 Description of wildlife in the affected area of SAC

In Table 15 the qualifying interests for the River Barrow and River Nore SAC are listed, and it is indicated whether these habitats and species would be present in the upper River Barrow in

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the general vicinity of the Triogue River confluence. Some of the species listed in Table 7 would occur only in the lower reaches of the River Barrow (i.e. the shads). Other species are non-aquatic so would not be affected directly or indirectly by the operation of a sewage treatment plant at Portlaoise (i.e. bats). Other species do not occur in the River Barrow (i.e. Pearl Mussels which are extinct). The species which do occur in the area are indicated in Table 15. These species are salmon, brook lamprey, white-clawed crayfish and otter. These species also occur in the River Triogue.

Table 15 Qualifying Interests for the River Barrow and River Nore SAC.

*This habitat was not recorded at the sites located upstream and downstream of the Triogue confluence so it is assumed for the purposes of the report that it is not present in the area.

5.3. I Aquatic ecological assessment (September 2008)

The results of the September 2008 on-site biological assessment of the River Barrow upstream (control) and downstream (receptor) of the Triogue River confluence are provided in Appendix 3. The results of the assessment are outlined below and also summarised in Table 16. Using the EPA Q rating index, the control site was rated as being ‘Slightly Polluted (Q3- 4)’ while the receptor site was rated ‘Moderately Polluted (Q3)’. Declines in all the other biotic indices were also recoded between the site located upstream of the Triogue confluence, and

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the receptor site. It must be noted that water quality in the Triogue River at the Barrow confluence is being influenced by factors other than the Portlaoise WwTP and storm water inputs from this town (i.e. agricultural activities, septic tanks etc.). The current survey was undertaken at the end of the operation of all the elements of the old plant. By early October components of the new plant were being utilised as part of waste water treatment process at Portlaoise. The new plant is expected to become fully operational during January 2009.

Table 16 Summary of biotic indices for the sites surveyed on the River Barrow in September 2008.

Q-ra ti ng BMWP Score BMWP interpretation

ASTP (Average Score per Taxon) TBI (Trent Biotic index) Chandler Index score P/R ratio index P/R ration index interpretation Juvenile salmonid food index

5.3.1 .I Annex II species

During the September 2008 survey two Annex II species were recorded during the kick sampling assessment; white-clawed crayfish and brook lamprey. These species were recorded at the sites investigated both upstream and downstream of the Triogue River confluence. Evidence of otter activity was also noted along this general stretch of river. The affected stretch of river is also known to contain salmon.

5.3.1.2 Q-rating

At the control site, 83% of the macroinvertebrates recorded were assigned to EPA pollution tolerant Group C, 10% were Group B, 6% were Group D and 2% of the organisms recorded were Group A (pollution sensitive). The two Group A organisms recorded were the autumn dun Ecdyonurus dispar (Heptaenidae) and the green drake mayfly Ephemera danica (Ephemeridae). Group B indicators (larvae of the banded jewelwing damselfly Agrion splendens and the stonefly Leufra fusca) were also common and accounted for 10% of the macroinvertebrate community. Jenkin’s spire shell Potamopyrgus jenkinsi (N=28) and freshwater shrimp Gamrnarus deubeni (N=l7) were the most common species making these pollution tolerant Group C organisms the most abundant pollution sensitivity group at this site. The only group D (very tolerant) organism recorded was the hog louse Asellus aquaticus which was found in fair numbers. The control site was therefore rated as being ‘Slightly Polluted (Q3-4)’ using the EPA biological monitoring system (Toner et a/, 2005).

The site surveyed downstream of the Triogue River confluence supported organisms in pollution sensitivity Groups B, C and D with no pollution sensitive group A indicators recorded. The overall community structure was as follows; Group C (82.5%), Group D (13.4%) and Group B (4.1%). The most abundant organism was the pollution tolerant freshwater shrimp which was numerous (N=41). Other group C indicators, Jenkin’s spire shell and the hog louse were found in fair numbers and common, respectively. Fair numbers of larvae of the grey flag caseless caddisfly Hydropsyche pellucidula were recorded while H. angustipennis was present. Water beetles (all Group C) featured strongly in the macro-invertebrate community at this site with riffle beetles, diving beetles, crawling water beetles and whirligig beetles recorded at various life stages.

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The only group B indicator recorded were banded jewelwing damselfly larvae of which there were small numbers. The parasitic fish leech Piscicola geornetra (Group C) and Glossiphonia cornplanafa (Group D) were both present. Taking into account the relative abundances of the macro-invertebrates recorded at this site and using the EPA biological monitoring system, (Toner et a/, 2005), this stretch of the River Barrow is considered to be ‘Moderately Polluted (Q3)’.

5.3.1.3 BMWP and ASPT

The BMWP (biological monitoring working party) score for the control and receptor site was 98.2 and 68.7, in that order. Correspondingly, the respective categories for the control and receptor site is ’Good’ (interpreted as Clean but slightly impacted)’ and ‘Moderate (interpreted as moderately impacted)’. The control site scored close to 100 so is close to being in the unpolluted category i.e. ~ 1 0 0 . Similarly, the receptor site is close to being in the ‘clean but slightly impacted’ category. In terms of biological water quality the receptor site was a level of magnitude lower than the control site using the BMWP system. The ASTP (average score per taxon) of the control and receptor site was 6.5 and 4.9, respectively. These results further emphasize that the ecological status of the River Barrow downstream of the Triogue confluence is reduced. Indeed, a BMWP score of >5.5 is a reflection of good water quality and the receptor site is above this threshold value.

5.3.1.4 Trent Biotic Index

The control site had 14 taxonomic TBl (Trent biotic index) groups and scored 8 using this index. The receptor site had 13 taxonomic TBI groups but had no stonefly or mayfly larvae. Two trichopteran (caddisfly larvae) species were recorded so the corresponding TBI score for this site was 7.

5.3.1.5 Chandler index

The Chandler biotic index score for the receptor site (33.9) was lowered by the diversity of beetles recorded at the site and also by the presence of leeches. The control site scored higher using the Chandler index (49.6) due to the presence of pollution tolerant species. However, both sites are deemed to be impacted and well below the satisfactory score of 80, reflecting polluted oxygen deprived conditions at both sites. The receptor site is significantly more impacted than the control site with a score difference of almost 16 between the two sites.

5.3.1.6 Functional group analysis

The control site had macroinvertebrates in four different functional feeding groups (FFG); grazers (37.6%), shredders (27.7%), predators (1 9.8%) and filtering collectors (1 4.8%). The trophic structure of the macro-invertebrate community at the receptor site downstream of the Triogue confluence changed significantly. At the receptor site, shredders (54.6%) were the dominant FFG, with grazers (1 9.6‘%), predators (12.4%), filtering collectors (12.4%) and gathering collectors (1%) also occurring. When compared to the control site, there was a partial displacement of grazers (mainly Jenkin’s spire shell and mayfly larvae) at the receptor site by shredders (mainly freshwater shrimp and hog louse). This represents a change in the ratio of gross primary production to community respiration; the ratio of scrapers to total collectors and shredders (P/R ratio) gives the ratio of gross primary production to community respiration. The control site was found to be autotrophic (P/R = 0.884) whereas the receptor site was heterotrophic (P/R= 0.288), a difference by a factor of over 3. This means that the control site can maintain itself and is not dependent on external inputs for its maintenance in contrast to the receptor site which is dependent on external inputs to the system for sustenance. The community at the downstream site has adapted to this situation to result in the present community structure. This further emphasizes the differences in the communities between the two sites and highlights an imbalance in the downstream site community.

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,

5.3.1.7 Juvenile salmonid food index,

The juvenile Salmonid food index suggested that ‘Unpredictable’ supply of invertebrate food was available for juvenile salmonids at both sites. This index is based on the ratio of behavioural drifters (filtering and gathering collectors) to accidental drifters (scrapers, shredders and predators). The ratio for the control and receptor site was 0.17 and 0.15, respectively. These predictions were brought about by small numbers of behavioural drifters (mostly grey flag caddisfly larvae) and relatively large numbers of accidental drifters (mainly freshwater shrimp, Jenkin’s spire shell, hog louse and banded jewelwing damselfly larvae).

5.4 Conservation Objectives for River Barrow and River Nore cSAC

The Conservation Management Plan for the River Barrow and River Nore SAC is currently being prepared by the National Parks and Wildlife Service (NPWS) of the Department of the Environment, Heritage and Local Government. However, a draft of this plan was available at the time of preparing the current report. A description of the site is provided in the NPWS Site Synopsis (See Appendix 1).

European and national legislation places a collective obligation on Ireland and its citizens to maintain at favourable conservation status areas designated as candidate Special Areas of Conservation. The Government and its agencies are responsible for the implementation and enforcement of regulations that will ensure the ecological integrity of these sites. According to the EU Habitats Directive, favourable conservation status of a habitat is achieved when “its natural range, and area it covers within that range, is stable or increasing, and the ecological factors that 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 data on the species concerned indicate that it is maintaining itself, and the natural range of the species is neither being reduced or 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”.

The conservation objectives of the draft Conservation Management Plan for the River Barrow and River Nore SAC are given in Table 17.

5.5 Impact Prediction / Assessment

5.5. I Introduction

The EIS for the new plant (MCOS/COWl, 2001) concluded that an estimated load of 13.7 kg Total Phosphorous was being discharged daily from the existing WwlW to the River Triogue and much of this was being conveyed downstream to the River Barrow. The new plant is designed to reduce the phosphorus loading to the River Triogue by a factor of 3.1 at 39,000 p.e. It was therefore concluded that “water quality in the river will thus improve as a higher quality effluent, with higher BOD and suspended solids removal along with nutrient (N, P) reduction, will result from the proposed upgrade to the works, which will lead to an increase in the diversity of species present”. Furthermore it was noted that “any upgrading of the existing WwTP is likely to have a beneficial impact on freshwater flora and fauna”. It was also noted that “in a wider context, upgrading of the WwTP will be carried out in conjunction with the improvement of the collection system thereby limiting the frequency of overt7ows from the sewer network to the order of 1 spill per year, with consequential additional benefit to the river”.

The upgrading of the collection network has been completed since the time the EIS was published and all storm water (with the exception of the old town) is now separated. The new plant includes a new storm water holding tank which will allow storm water to be intercepted and stored prior to circulation through the treatment plant. It is not envisaged, except under exceptional circumstances, that untreated sewage will be released into the Triogue. It is

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accepted than any benefits to water quality in the River Thogue will also benefit the downstream River Barrow. The EIS concluded that the new plant would have an overall significant positive impact on the River Triogue and the River Barrow. However, it should be noted that replacement of one non-complaint discharge with another, albeit less non- complaint discharge, should not necessarily be interpreted as a positive impact as EIA procedure requires developments to be assessed on their own individual merits.

Table 17 The conservation objectives of the draft Conservation Management Plan for the River Barrow and River Nore SAC (supplied by NPWS).

at favourable conservation status: Estuaries; Mudflats and sandflats not covered by seawater at low tide; Salicornia and other annuals colonising mud and sand; Atlantic salt meadows (Glauco- Puccinellietalia maritimae); Mediterranean salt meadows (Juncetalia maritimi); Water courses of plain to montane levels with the Ranunculion fluitantis and Callitricho-Batrachion vegetation; European dry heaths; Hydrophilous tall herb fringe communities of plains and of the montane to alpine levels; Petrifying springs with tufa formation (Cratoneurion); Old sessile oak woods with Ilex and Blechnum in British Isles; Alluvial forests with Alnus glutinosa and Fraxinus excelsior (Alno-Padion. Alnion incanae. Salicion albae) To maintain the Annex II species for which the cSAC has been selected at favourable conservation status: Vertigo moulinsiana; Margaritifera margaritifera; Austropotamobius pallipes; Petromyzon marinus; Lampetra planeri; Lampetra fluviatilis; Alosa fallax; Salmo

I To maintain the extent, wecies richness and biodiversity of the entire

I users and relevant authorities.

The overall conclusion of the EIS was that “the upgrading of the WwTP will result in a higher quality effluent and will therefore have a positive impact on the receiving freshwater fauna and flora”. Although this was true, the fac:t that the proposed discharge was predicted in the EIS to continue to have a significant impact on the receiving water was not noted in the conclusions of the freshwater environment chapter (as the discharge would be above the receiving water’s assimilative capacity). Likewise, the predicted non-compliance of the effluent standards proposed with Phosphorus Regulations was not taken into account in the impact assessment process. The replacement of one non-complaint discharges with another, albeit significantly less so, non-complaint discharge should also not have resulted in the overall positive impact assessment that was made. It was considered in the EIS that any improvement over the existing situation would result in a positive impact. However, the proposed new discharge should be regarded as a separate entity and therefore judged in isolation of the existing circumstances before being considered under a ‘Do Nothing Scenario’ and as a cumulative impact. An assessment of the proposed discharge on its own would have resulted in a conclusion of significant negative effects. Nonetheless, alternatives were considered in the EIS, and discharge of the treated effluent into other local watercourses (i.e. Barrow) was identified as having potentially more serious effects. The public interest can of course also be made, along with the clear technical difficulties involved in delivering a treated effluent that would be within the assimilative capacity of the relatively small River Triogue. The proposed plant will of course also deliver significant benefits over the ‘Do Nothing Scenario’.

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With the operation of the new plant new WwTP, pollution in the River Triogue a will certainly be much reduced from that which has recently been the case with the old plant. However, unless the River Triogue can be returned to a satisfactory status there is the potential of impacts on the habitats and species of the River Barrow SAC by three mechanisms:-

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Pollution of downstream SAC areas; Reduction of potential spawning habitat for salmon and lampreys living in the SAC; Reduction of potential forging habitat for otters living in the SAC;

The first impact would occur as a result of ongoing poor water quality in the River Triogue resulting in poor water quality in the River Barrow downstream of the confluence of the two rivers, as is currently the case. If the scale of pollution was reduced this should continue to be assessed as negative impact if there is any ongoing effect on water quality in the SAC. Impacts such as sub-lethal effects on fish (i.e. intersex changes) should also be considered.

The second mechanism would occur as a result of habitats in the River Triogue which could potentially be used for some part of the life cycle of Annex I I species in the River Barrow remaining unavailable as a result of degraded water quality. Although not part of the SAC, the Triogue sub-catchment clearly has the potential to contribute to the favourable conservation status of Annex I I species within the Barrow and Nore SAC. For example, the Triogue River is still used by the Annex I I species such as salmon, lampreys and white-clawed crayfish. According to the Southern Regional Fisheries Board, during the investigation of a fish kill in during October 2007 on the River T’riogue upstream of the Portlaoise WwTP, these species were among the species recorded. All of these species are listed as conservation interests for the Barrow and Nore SAC. Production of these species in the River Triogue therefore can be expected to contribute to some degree to the overall Barrow populations of these listed species. For example, a proportion of the salmon running upstream on the River Barrow can be expected to return to the River Triogue to spawn. Therefore production in the River Triogue has the potential to influence the number of these fish within the Barrow SAC at any one time. The fact that this species is currently under decline in this catchment is significant.

Although brook lampreys use the sluggish areas of the River Barrow for nursery purposes (i.e. in the vicinity of the Triogue confluence), the overall viability of the population will depend of the availability of clean gravelly streams upstream of such areas for spawning purposes. Therefore as with salmon, recruitment of lampreys into the SAC can be influenced by spawning habitats located outside the boundary of the site. Habitats physically suited for lamprey production occur throughout the Triogue River but have been unavailable for lamprey production for some time due to degraded water quality.

Otters on the River Barrow can be expected to take advantage of fish stocks in tributary streams such as the Triogue sub-catchment in addition to fish returning to and from such area. An ongoing suppression of the fisheries production potential of the Triogue can therefore be interpreted as an ongoing significant negative impact on the otter populations within the SAC. So although it is clear that improvements in water quality in the River Triogue as a result of the operation of the new plant will deliver benefits for Annex II listed and other aquatic life over the ‘Do Nothing Scenario’, the impact assessment must identify that this is a reduction in a negative impact rather a true positive impact if water quality in the river is not returned to a satisfactory status.

Retaining sub-populations of species in tributaries is particularly important for the numerical and genetic security of a population. For example, following catastrophic pollution events the re-colonisation of species is often from unaffected tributary streams. In the case of the Barrow and Nore SAC, the absence of Pearl Mussel populations in tributaries of the main channel has been cited as a key constraint to the population ever making a successful recovery in the main channel (Moorkins, 1999).

The key test in the current assessment is however if the discharges, from the existing and new plants, are / will affect the conservation objectives of the SAC (See Table 14). This is addressed in the following sections.

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5.5.2 Impact of the existing plant

According to MCOSlCOWI (2000) the effects of the Portlaoise WwTP outfall is “a distinct and severe degradation of the water quality of the River Triogue”. This report also noted that “average background concentration [of orthophosphate] rises downstream of the outfall at Kyle Bridge to 0.57 mgb, a tenfold increase from the background levels”. Although the report noted that “there is some reduction in the concentration of orthophosphate to 0.27 mgb at Kilmainham” which is located some 10km downstream of the WwTP outfall. However considering the increase in volume at this point (0.09 m3 sec-‘ to 0.32 m3 sec-‘) this reading reflects an actual increase in orthophosphate loadings if expressed as kg day“ (4.4 kg day-’ to 7.5 kg day”).

The same report noted that the average level of Orthophosphate in the River Barrow upstream of the confluence of the Barrow and Triogue was 0.056 mg/l but that the “average concentration downstream of the confluence is 0.087 mg/l which equates to an average percentage increase of around 64%”. This document also noted that ”the level of Orthophosphate does not significantly reduce with distance downstream of the confluence. Hence, the effects of the Triogue are significant on the Barrow Orthophosphate concentration, particularly in the context of the Phosphorous regulations”. The November 2006 to September 2007 monitoring data (Appendix 2) shows that interim upgrades may have improved the operation of the old plant since the MCOS/CPWI (2000) study. During this period the mean upstream orthophosphate concentrations were a similar 0.06 mg/l rising to an average of 0.18 mg/l (300% increase) downstream of the plant.

Three stations are monitored by the EPA downstream of Portlaoise (downstream of the existing WwTP outfall); Kyle Bridge (0200), the Bridge near Eyne (0300) and the Triogue Bridge (0400). With the exception of 1989 and 1993 when it was rated as ‘Moderately Polluted’, the Kyle Bridge station has been consistently been rated as ‘Seriously Polluted, Unsatisfactory’ since biological monitoring began in 1971. In the first survey biological water quality was rated as ‘Seriously Polluted’ (Ql), with such conditions pertaining in 1974 (Q2-3), 1978 (Ql), 1980 (Ql), and 1984 ((12). During 1986 and 1989 this site was rated as Q2-3 (Moderately Polluted), and was rated as Q3 (also Moderately Polluted) in 1993. However in recent years this has again been cansistently rated as Q2. The site at Kyle Bridge has also been influenced by pollution sources in the past, including the Tip stream which drains a landfill site. Numerous fish kills were reported from the River Triogue at the time of preparing the EIS for the new plant (MCOS/COWl, 2001). In 1997 and 2000, the water quality at Kyle Bridge was rated as Q2 and was found to be the same in 2006 when monitored by the EPA (Neill, 2007).

Further downstream at Station 0300, water quality was generally slightly better than at Kyle Bridge prior to the 1980’s but water quality results for these two sites are comparable from the 1980’s. In recent years (2000 and 2003), Station 0300 has been rated as ‘Moderately Polluted (Q3)’ while it was slightly worse in 2006 (Q2-3). The station furthest downstream is at Triogue Bridge (0400) where biological monitoring by the EPA commenced in 1989. In this year, the water quality of the Triogue at this point was rated as ‘Moderately Polluted (Q3)’. In 1993, there was a slight improvement with a rating of ‘Slightly Polluted (Q3-4) assigned at this station but in the four most recent surveys (1997, 2000, 2003 and 2006), the water quality had declined to Q3.

In the EPA Report ‘Water Quality in County Laois, 2007” it is reported that orthophosphate levels on the River Triogue increased from 0.03 mg/l upstream of the outfall on the 15 May 2007 to 0.18 mg/l downstream of the plant on the same day (600% increase). The EPA monitored both sites only on this day during 2007. The same report notes that during 2007 there was “a significant loss of quality [in the River Barrow] downstream of the Triogue River confluence”. This document reported that the average orthophosphate concentration in the River Barrow upstream of the Triogue confluence was 0.028 mg/l while the corresponding downstream concentration was 0.058 mg/l. This represents an increase of over 100% and a decline from unpolluted to moderately polluted conditions (under the Phosphorous Regulations). The current Septemher 2008 biological assessment of sites on the River Barrow located immediately upstream and downstream of the Triogue confluence found that

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there was a decline from slightly polluted (Q3-4) to moderately polluted conditions. A decline in the BMWP index also suggested a decline from “clean but slightly impacted” conditions to “moderately impacted” conditions between the site on the Barrow upstream of the Triogue confluence and the 150m site downstream.

Water quality has been monitored in the River Barrow main stem and in selected tributaries by the Environmental Protection Agency (EPA) and its predecessors since 1971. Both chemical and biological variables have been measured. The main channel was surveyed in 2003 (Clabby et al, 2004) and some overall improvement in water quality was reported when compared to data from 1997 and 2000. However, eutrophication continued to be widespread. The sources of this enrichment varied with location in the catchment. Agriculture and peat harvesting were identified in the upper reaches of the main stem and suspected sewage and other discharges were associated with the urban centres, including Portlaoise.

Toner et al. (2005) concluded that there was an overall improvement in the water quality results for the River Barrow since the previous 2000 survey (McGarrigle et al, 2002). This was despite the fact that water levels were generally below normal during the most recent survey thus providing less dilution capacity for wastes. However, the EPA concluded that eutrophication continued to be widespread in the river due to suspected agriculture in the upper river and to sewage discharges from towns, particularly Portlaoise and Mountmellick.

The closest EPA station downstream of the Barrow - Triogue confluence is Portnahinch Bridge (Station 0600). This station is located approximately 2 km downstream of the confluence of these two rivers. Since biological monitoring of this station began, the water quality has consistently been either ‘Slightly polluted (Q3-4)’ or ‘Unpolluted (Q4)’. From 1986 to 1997, the water quality was rated as Unpolluted (Q4)’ but was rated as ‘Slightly polluted (Q3-4) in subsequent surveys (2000 and 2003). In 2006, the River Barrow was sampled by the EPA on behalf of Laois County Council at Kilnahown Bridge. This is located approximately 6 km downstream of the Barrow - Triogue confluence and was also rated as ‘Slightly Polluted (Q3-4)’ in 2006. Selected water quality parameters from Neil1 (2007) for the River Barrow at the bridge SE of Hammerlane (0.7 km downstream of the Triogue confluence) are provided in Table 6. From 7 samples, Colour Hazen (6), Nitrite (4), Ortho-Phosphate (3) D.O. Sat (I), B.O.D. (I), Ammonia (1) and Unionised Ammonia (1) were elevated (numbers in parentheses represent the number of times the parameter was elevated).

>

Although it is likely that the Triogue River will be receiving inputs from other sources along its c.13km course from the WwTP outfall to the Barrow confluence, it is clear that the primary influence of water quality in the catchment is the Portlaoise outfall. EPA (2007) noted that “the Triogue is seriously polluted downstream of the Portlaoise Sewage Treatment Works (high BOD, orthophosphate, ammonia, nitrite and chloride and low Dissolved Oxygen). This report also noted that “there are carryover effects at the downstream stations and the river remains unsatisfactory to the confluence with the River Barrow” and that there was “a significant loss of quality [in the River Barrow] downstream of the Triogue River confluence”.

Table 18 provides the results of the discharge and receiving water model for the existing Portlaoise WwTP based on 99%ile, 95%ile, and 50%ile flows in the River Triogue immediately downstream of the Portlaoise WwTP outfall. Data for background concentrations was taken from Laois County Council water quality monitoring data for the River Triogue upstream of the Portlaoise WwTP outflow during the period November 2006 to September 2007. Plant discharge data is based on the January to September 2007 monitoring data for the existing plant outlet. All calculations relate to existing plant normal flow of 6,000m3/day. In this assessment it can be seen that Orthophosphate levels in the River Triogue downstream of the Portlaoise WwTP are elevated above the limit level taken for this parameter. This is due to the poor assimilation capacity in the river for this parameter and also the poor dilution levels available. Table 16 illustrates the impact of the River Triogue on the River Barrow under the old plant scenario. The decline in water quality in the River barrow downstream of the Triogue confluence occurs due to poor dilution and assimilative capacity of the River Barrow at this point.

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Therefore it must be concluded that the existing discharge is having an indirect but significant adverse effect on the River Barrow SAC as a result of pollution of the River Triogue being carried downstream into the SAC boundary resulting in a decline in water quality status in the River Barrow downstream of the Triogue confluence. This conclusion is backed up by both theoretical and observed data and also even visual observations (see Plates 1-3). Pollution of the River Triogue is also thought to results in a loss of habitats which could provide for recruitment of Annex II species into the SAC and provide foraging activities for otters. Physiological effects on fauna within the SAC could also potentially occur. The overall impact of the existing discharge is therefore assessed as Substantial Negative. This impact is defined as “a change in the ecology of the affected site which has noticeable ecological consequences outside the development boundary. These consequences are considered to significantly affect the distribution and/or abundance of species or habitats of conservation importance”. Due to the high water quality requirements of Atlantic salmon and their current declining status in the River Barrow the impact of the existing discharge on this species is assessed as ‘Substantial Negative’.

5.5.3 Impact of the new plant

Table 18 provides the results of the discharge and receiving water model for the new Portlaoise WwTP based on 99%de, 95%ile, and 50%ile flows in the River Triogue immediately downstream of the Portlaoise WwTP outfall. Table 19 gives corresponding results for the existing plant. Data for background concentrations was taken from the EPAs Water Quality in County Laois reports for 2007 and 2008 (Neill, 2007, 2008). Data is presented as the mean for the available 2006 and 2007 data. It must be noted that there is a wide variation in values such a dataset. Mean values can be strongly influenced by individual high values which will often correspond to the concentration of pollutants during low flows. During normal flows (or median flows) there would however be much more dilution available for background contaminants and peak values observed would not normally be expected to be associated with those conditions.

This is always the problem with using water quality monitoring data where information of flow rates are not available to calculate actual loadings. Therefore the current assessment must be considered to be approaching a ‘worst case scenario’. It should be stressed that the mean concentrations used in the analysis for determination of assimilation capacity may not truly reflect conditions in the river. The EPA state that continuous records of chemical concentration and flow would form the ideal basis for water quality assessment but in practice this is impossible for financial, technical and logistical reasons. Reliance must therefore be placed on discrete samples because such samples constitute only a minute fraction of the whole body of water under investigation and because they are only representative of conditions at the particular time of sampling the interpretation of data arising from such samples requires great care. Therefore when interpreting chemical data, it must be considered that flows in the river would not always be at the 95Y0ile flow. In fact, a 95Yoile flow is that flow which is available or exceeded in the river for 95% of the time. This is representative of low water levels and any river flows at or below the 95%iIe flow for only 5% of the time. Chemical surveys extend throughout the year and flows greater than the 95%ile flow (greater volumes of water) would be realised most of the time, especially during the wetter months. Indeed, it is possible that in any given year, all water samples taken for chemical analysis would be taken at flows greater than the 95%ile flow. Therefore, in calculating assimilative capacity and chemical loading for the Triogue and Barrow Rivers under a 95%ile flow, the resulting downstream concentration of parameters would certainly represent the ‘worst case scenario’. Chemical concentrations with corresponding flows on the day of sampling would provide a better insight into the chemical water quality of the subject rivers.

Plant discharge data is based on design figures and estimates provided by Laois County Council. All calculations relate to plant normal flow of 9,025 m3/day (0.1 m3 sec-’). This flow is actually larger than the 95%ile flow of the Triogue at this location and would be equivalent to almost 19% of the flow in the River Barrow downstream of the Triogue confluence. The design dry weather flow from the plant is 8,775 m3/day. This is only 2.7% lower than the normal flow from the plant so would not be significantly different.

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The Third Schedule of the Phosphorous Regulations requires that the existing water quality of the Triogue and the Barrow must be upgraded from a biological quality rating of Q2 and Q3-4 to Q3 and Q4 respectively (by 2007). Therefore the target Orthophosphate value for 2007 for the Triogue and Barrow Rivers was 0.07 mg/l (Moderately Polluted) and 0.03 mg/l (Slightly Polluted) respectively. After 2007, the required Q rating for all Irish Rivers should ideally be Q4 which relates to an orthophosphate concentration of 0.03 mgll. MCOS/COWI (2000) noted that a minimum water quality rating of “Q3-4 would be required to protect salmonid fish in the Triogue”. This would equate to a target annual median orthophosphate level of 0.03 mg/l. However, it is noted that with the high background mean orthophosphate levels currently being observed in the Triogue River this would be impossible to attain at present as the background level itself is in significant breach of these standards.

However, based on the design criteria for the new plant even if the background Orthophosphate levels in the Triogue were zero, the discharge from the new plant would still elevate levels of this parameter downstream of the plant to 0.13 mg/l under 95%ile flow (a ‘worst case scenario’). This is based on an estimated Orthophosphate level in the discharge of 0.21 mg/l (see Section 3.1.4.2) of Orthophosphate and the normal flow predictions for the plant. For a 50%ile flow the downstream concentration would be 0.069 mg/l, which would still result in unsatisfactory water quality conditions downstream of the plant. However, this would be just within the agreed 0.07 mg/l standard for this stretch of river and is approaching satisfactory conditions. Interestingly, if the discharge was directly into the River Barrow downstream of the Triogue confluence under a scenario where both rivers were pristine, the emissions from the new plant would still elevate orthophosphate levels on the Barrow to 0.06 mg/l under 95%ile flows. This would also therefore result in unsatisfactory water quality conditions. However, it is clear that if the Triogue River was clean it would be likely be able to assimilate much if not all of the input of the new plant as a result of river assimilation and recovery processes. Even in a deteriorated state there would still be uptake by plants and microbes and adsorption and fixing by physical and chemical processes. Therefore discharging the effluent into the River Triogue, even at levels above its assimilation capacity, is likely offer a higher level of protection to the SAC rather than releasing this effluent directly into the River Barrow.

Nonetheless, it must be concluded that the new discharge will again continue to have an indirect but significant negative effect on the River Barrow SAC. This is because the discharge will continue to affect water quality in the River Barrow by exacerbating water quality problems. It will also continue to prevent the Triogue River from recovering to satisfactory status. However, that said the new plant will represent a significant improvement over the old plant and will bring moderate positive benefits to both the Triogue and River Barrow as a result of the significantly improved treated effluent quality and separation /control of storm water inputs. The overall impact of the existing discharge is assessed as Minor Negative. This impact is defined as “a change in the ecology of the affected site which has noticeable ecological consequences outside the development boundary, but these consequences are not considered to significantly affect the distribution or abundance of species or habitats of conservation impoltance”. Due to the high water quality requirements of Atlantic salmon and their current declining status in the River Barrow the impact of the existing discharge on this species is assessed as ‘Moderate Negative’.

Table 20 gives the conservation objectives of the draft Conservation Management Plan for the River Barrow and River Nore SAC and impacts of the existing and new plants. Table 21 provides the qualifying interests for the River Barrow and River Nore SAC along with impacts for each habitat and species listed iii the SAC brought about by the existing and new plant. The conservation objectives for the River Barrow are to maintain habitats and species for which the SAC was selected (NPWS). Conservation objectives of the management plan for the River Barrow include maintaining the Annex II species for which the SAC has been selected at favourable conservatiori status. Though the new plant is envisaged to have moderate negative effects on this objective, it is a significant improvement on the impact of the existing discharge on Annex II species (generally substantial negative). When the River and Nore SAC site was being selected water quality in the River Triogue was ‘Unsatisfactory’. Should background pollution levels remain constant, positive changes in water quality would

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be expected with the operation of the new plant and the status of the pollution status of the River Triogue could improve. This would ultimately have positive benefits for the River Triogue, and River Barrow downstream of the River Triogue confluence when compared to the existing situation. The overall impact assessment of the existing discharge on the qualifying interests of the SAC is rated as moderate negative while the impact of the new discharge is rated as being minor negative.

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River Standards

Table 18 The results of the discharge arid receiving water model for the new Portlaoise WwTP based on 99%ile, 95%ile, and 50%ile flows in the River Triogue immediately downstream of the outfall. River values considered to be elevated are highlighted in bold. All calculations relate to proposed plant normal flow of 9,025m3/day. Background concentrations are mean values taken from data combined from Neill 2007 and Neill 2008.

BOD (mg/l) Ortho- Ammonia Nitrite Nitrate Suspended phosphate (mgll N) (mgfl N) (mgll) Solids (mg/l) (mgfl)

level) , (estimated '

<5 <0.07** <0.1 <0.1 <7 <25

Background

Discharge

99%ile flow (0.05m3/s)

flow (0.09 m%)


1.7' 0.04* 0.15' .038' 4.84* 1 o** 6.8 0.21 3 1 .I 7.3 10 5.15 0.15 2.07 0.76 6.5 10

4.44 0.13 1.7 0.6 6.16 10

2.58 0.069 0.6 0.22 5.2 10

1 - I , , . .: , . , : .".; . .). ti.,'' .;

I ,

9 8 '

j I > , I " . ;

River Standards

BOD(mgl1) Ortho- Ammonia Nitrite Nitrate Suspended phosphate' (mgfl N) (mgll (mgfl), Solids (mgll)

" , (mgfl) N)

. . 1 I

'

<5 <0.07" <0.1 <0.1 <7 <25

30

Background

Discharge 99%ile flow (0.05m3/s)

flow (0.09 m h )


1.7' 0.04* 0.15* .038* 4.84' IO*"

9 0.64*** 9.5 1 .I 7.3 31 5.9 0.38 5.6 0.6 6.2 22.2

4.9 0.30 4.2 0.5 5.9 19.1

2.6 0.11 1.3 0.17 5.14 12.6

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Natura Code

Table 20 The conservation objectives of the draft Conservation Management Plan for the River Barrow and River Nore SAC (supplied by NPWS) and impacts of the existing and new plants.

Item Description . ' . . Impact, . of lmpactofnew existing plant plant

Number 'Objective Existing New plant . a discharge

I I To maintain the Annex I habitats for which the SAC I Not I Not _ - I has been selected at favourable conservation status. I significant

objective 2 I To maintain the Annex II species for which the SAC I Substantial I Moderate I significant

II To maintain the extent. species richness and I Moderate I Minor

Table 21 Qualifying Interests for the River Barrow and River Nore SAC.

I I 1833 I Slender naiad (Na1a.s flexilis) 1 Noimpact I Noimpact Killarney Fern (Trichomanes speciosum) No impact No impact

No impact No impact Substantial Moderate

I I negative 1 negative 1 103 I Twaite shad (Alosa alosa) I Noim~act I Noim~act 1102 I Allis shad (Alosa fallax) I Noimpact I Noimpact 1096 I Brook lamprey (Lampetfa planeri) I Moderate I Minor

the Ranunculion fluitantis and Callitncho-

*This habitat was not recorded at the sites located upstream and downstream of the Triogue confluence so it is assumed for the purposes of the report that it is not present in the area.

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6. Stage 3: Assessment of Alternative Solutions

The principal alternatives examined in the development of the Portlaoise WwTP scheme were:

Relocation of the treatment works further downstream on the Triogue or at the confluence of the rivers Triogue and Barrow where the greater baseflows in the river would be available, which might permit less rigorous effluent standards;

Pumping of effluent from the treatment works site downstream to the river Barrow for discharge at the Triogue cortfluence or further downstream;

The options of relocating treatment or discharge to locations further downstream in the river system were rejected on the following grounds:

They were not considered sustainable in that they could compromise discharges or water abstractions associated with other communities lower down the catchment;

The costs involved in these options were significantly higher than for upgrading of the existing works.

Based on assessment of the available alternatives in the EIS, the proposed scheme was selected as the optimum scheme following technical, environmental and economic appraisal of all feasible alternatives.

One of the conclusions of the current report is that discharging the effluent into the River Triogue even at levels above its assimilation capacity is likely offer a higher level of protection to the River barrow and River Nore SAC than releasing this effluent directly into the River Barrow. The conclusions of the current assessment therefore support the conclusions made in the EIS.

7. Stage 4: Assessment Where Adverse Impacts Remain

It has been established in the current and previous reports that the existing discharge from the Portlaoise WwTP is having a significant adverse environmental impact. However, as this plant is currently being decommissioned the assessment of this plants impact is only of relevance in outlining the baseline situation. It is expected that the new plant will be fully operation al by January 2008.

The appropriate assessment process completed above has concluded that adverse effects will still remain and that the overall impact on the River Barrow SAC as result of the discharge from the new Portlaoise plant will Be Minor Negative. However there are a number of significant mitigating circumstances 1:hat must be taken into account. Of primary importance is that the new plant will deliver a treated effluent of significantly higher quality that is current being discharged. The new Portlaoise WwTP is a state of the art facility which will treat waste to the highest technical standards available (under B.A.T.N.I.E.C. principles). Therefore this will be a moderate positive impact when compared to the ‘Do Nothing Scenario’. It must also be appreciated that alternatives to discharging into the Triogue have been fully considered and the proposed scheme was selected as the optimum scheme following technical, environmental and economic appraisal of all feasible alternatives. It is clear that discharging of the effluent directly into the River Barrow SAC would be less preferable than the current scheme. There are no other feasible alternatives available.

It is also noted that most of the models used in the current Appropriate Assessment rely on maximum design parameters and 95%ile flows. This assessment is probably therefore assessing a situation approaching a ‘worst case scenario’. Although 95%ile flows are the river flows which are achieved or exceeded 95% of the time, normal river flows are generally in excess of the 95%ile level; therefore providing additional dilution capacity. It is also quite likely that the plant will perform better than expected. This is particularly likely in the case of the key

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parameter Orthophosphate. There is no design level for this parameter and predictions are based on a three sample comparison between Total Phosphorus and MRP. Therefore the final observed levels may well be much better than those used in the current study.

The scheme will deliver significant environmental benefits when compared to the existing situation and is also of very high public interest. It can be predicted that even with slight improvements in water quality in the Triogue River that numbers of salmon, trout and crayfish in the river will increase. This will improve the overall favourable conservation status of these species in the area and consolidate a population and genetic reservoir for these species upstream of the SAC. It is clear than any reduction of nutrient loading being brought by the Triogue River into the SAC will be a significant positive benefit compared to the current situation.

Therefore using the flowchart in Figure 1 this scheme will pass the Appropriate Assessment criteria.

The following general recommendations are made:-

0 Every effort be made by Laois County Council to work with other relevant agencies to reduce background pollutiori levels in both the River Triogue and River Barrow.

0 During the water quality monitoring as part of the operation of the plant, it is important that that flow rates are also determined on each occasion. It also recommended that a specific monitoring programme of flows and water quality upstream and downstream of the Triogue confluence be initiated.

0 It is also recommended that annual biological monitoring be undertaken upstream and downstream of the WwTP outfall and also upstream and downstream of the Triogue confluence with the Barrow.

8. Conclusion

The overall conclusion is that the Portlaoise WwTP satisfies the Appropriate Assessment process in that it will deliver significant benefits over the existing situation and is a scheme of high public interest which is the optimum possible scheme considering technical, environmental and economic constraints. It is recommended that a discharge licence be granted for the scheme and interim licence also issued to cover the gradual phasing out of the existing plant between now and January 2009.

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REFERENCES

General references

Armitage, P. D.; Moss, D.; Wright, .J. F. and Furse, M. T. (1983) The performance of a new biological water quality score system based on macroinvertebrates over a wide range of unpolluted running-water sites. Water Res., 17 (3), 333-347.

Barbour, M.T. and J.B. Stribling. 1991. Use of Habitat Assessment in Evaluating the Biological Integrity of StreamCommunities. Biological Criteria: Research and Regulation: 25- 38. EPA-440/5-91-005. Washington, DC: Office of Water, US EPA

Bowers Marriott, B. (1 997) Practical Guide to Environmental Impact Assessment: A Practical Guide. Published by McGraw-Hill Professional, 1997, 320 pp.

Chandler, J.R. (1 970) A Biological Approach to water Quality Management. Water Poll. Cont. 69141 5-421.

Curtis, T.G.F. & McGough, H.N. (1988) 1 Vascular plants. The Irish Red Data Book. The Stationery Office, Dublin.

Colhoun, K. (2001). Irish Wetland Bird Survey 1998-99. BirdWatch Ireland, Dublin.

Curtis, T. G. F. and McGough, H. N. (1988). The Irish Red Data Book. 1. Vascular plants. The Stationery Office, Dublin.

CFB (1993) Game Angling. Central f7sheries Board Irish Angling Guides. Gill and MacMillan.

EPA (2001 ) Parameters of Water Quality - Interpretation and Standards. Environmental Protection Agency, Ireland.

European Commission (1999) Interpretation manual of European Union Habitats Eur 15/2. EC DG Environment, Brussels

Flora (Protection) Order 1999. Statutory Instrument No. 94 of 1999. The Stationery

Office, Dublin.

Fossitt, J. (2000) A guide to habitats in Ireland. The Heritage Council, Kilkenny.

Hayden and Harrington (2000) Exploring Irish Mammals. Duchas The Heritage Service.

Lucy, J. (1998) The Barrow, The Nore and The Suir. In: Studies of Irish Rivers and lakes Ed. Christopher Moriarty. Essays on the occasion of the XXVl l Congress of Societas Internationalis Limnologias (SIL). Marine Institute. Dublin.

Lucey, J., 2007. Water Quality in Ireland 2006 - Key Indicators of the Aquatic Environment. EPA, Wexford

MacCarthaigh (1997) Hydrological data. A listing of water recorders and summary statistics at selected gauging stations. Environmental Protection Agency, Ireland.

McGarrigle, M.L., Bowman, J.J., Clabby, K.J., Lucy, P., Cunningham, M.,MacCarthaigh, M., Keegan, M., Cantrell, B., Lehane, M., Clenaghan, C., Toner, P.F. (2002) Water Quality in Ireland 1 998-2000. Second (Revised) Edition. Environmental Protection Agency.

MCOS/COWI (2001) Portlaoise Main Drainage: Environmental Impact Statement (EIS) for the Upgrade of Portlaoise Wastewater Treatment Works. August 2001. Laois County Council.

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MCOS/COWI (2000) Portlaoise Main Drainage Preliminary Report. Technical Report Number 1. Portlaoise Waste Water Treatment Works Receiving water Assessment. Laois County Council.

Nelson, B., & Thompson, R., (2004) The Natural History of lrelands Dragonflies. Ulster Museum. 454pp.

NRA (2004) Environmental Impact Assessment of National Road Schemes - A Practical Guide, National Roads Authority, Dublin

O’Reilly, P. (2004) Rivers of Ireland .- a flyfisher’s Guide. 5‘h Ed. Merlin Unwin Books.

Preston, C. D., Pearman, D. A. and Dines, T. D., eds (2002). New Atlas of the British and lrish flora. Oxford University Press, Oxford

Rabenil, C.F.,, Doisy, K.E. and Zweig, L.D. (2005) Stream invertebrate community functional responses to deposited sediment Journal of Aquatic Sciences. 67(4):395-402.

Toner, P., Bowman, K., Clabby, K., Lucey, J., McGarrigle, M, Concannon, C., Clenaghan, C., Cunningham, P., Delaney, J., O’Boyle, S., MaCarthaigh, M., Craig, M., and Quinn, R. 2005. Water Quality in Ireland 2001 -2003. Environmental Protection Agency, Wexford.

Whilde, A. (1993) Threatened mammals, birds, amphibians and fish in Ireland. lrish red data book 2: vertebrates. Belfast: HMSO.

Walley W.J. and Hawkes H.A. (1997) A computer-based development of the Biological Monitoring Working Party score system incorporating abundance rating, biotope type and indicator value. Wafer Research, 31 (2), 201-210.

Woodiwiss, F. (1960) Trent Biotic Index of Pollution. Second Quinquennial Abstract of Statistics Relating to the Trent Watershed. Trent River Authority. England.

Information sources on protected species

King, J.J. (2006) The status and distribution of lamprey in the River Barrow SAC. lrish Wildlife Manuals No. 21. National Parks and Wildlife Service, Department of Environment, Heritage and Local Government, Dublin, Ireland.

Kelly & King (2001) A review of the ecology and distribution of three lamprey species, Lampefra fluviafilis (L.), Lampefra planeri (Bloch), and Pefromyzon marinus (L.): A context for conservation and biodiversity considerations in Ireland. Biology and the Environment. I01 B(3): 165-1 85.

Kurz, I . and Costello, M. J. (1999). An outline of the biology, distribution and conservation of lampreys in Ireland. lrish Wildlife Manuals No. 5. Duchas, the Heritage Service, Dublin.

Lucey, J., and McGarrigle, M.L.(1987) The distribution of the crayfish Ausfropofarnobius pallipes (Lereboullet) in Ireland. lrish fisheries lnvesfigafions Series A (29):l-13.

Moorkens, E. A. (1 999). Conservation management of the freshwater pearl mussel Margarififera margarififera. Part 1 : Biology of the species and its present situation in Ireland. lrish Wildlife Manuals No. 8. Duchas, the Heritage Service, Dublin.

Information sources for identification fauna

Bass J.(1998) Last-Instar Larvae and Pupae of the Simuliidae of Britain and Ireland: a Key with Brief Ecological Notes 1998, 104pp.

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Cranston P.S. (1982) A Key to the Larvae of the British Orthocladiinae (Chironomidae) 1982, 152pp + 1 plate.

Disney R.H.L. (1 999) British Dixidac! (Meniscus Midges) and Thaumaleidae (Trickle Midges): Keys with Ecological Notes 1999, 128pp.

Edington J.M. & A.G. Hildrew (1995) A Revised Key to the Caseless Caddis Larvae of the British Isles, with Notes on their Ecology 1995, 134pp.

Elliott J.M. & K.H. Mann (1979) A Key to the British Freshwater Leeches, with Notes on their Life Cycles and Ecology. 1979 (reprinted 1998), 72pp.

Elliott J.M. & U.H. Humpesch (1988) A Key to the Larvae of the British Ephemeroptera, with Notes on their Ecology1 983, 101 pp .f 1 plate.

Gledhill, T., D.W. Sutcliffe & \N.D. Williams (1993) British Freshwater Crustacea Malacostraca: a Key with Ecological Notes 1993, 176pp.

Haslam, S., Sinker, C. & Wolsely, P. (1995) British Wafer Plants. Field Studies Council, Shrewsbury.

Hynes H.B.N. (1977) A Key to the Adults and Nymphs of the British Stoneflies (Plecoptera), with Notes on their Ecology and Distribution. Third edition, 1977 (reprinted 1993), 92pp.

Macan T.T. (1994) A Key to the British Fresh- and Brackish-Water Gastropods, with Notes on their EcologyFourth edition, 1977 (reprinted 1994), 46pp.

Savage A.A. (1989) Adults of the British Aquatic Hemiptera Heteroptera: a Key with Ecological Notes1 989, 173pp.

Savage A.A. (1999) Keys to the Larvae of British Corixidael999, 56pp.

Wallace, I.D., B. Wallace & G.N. Philipson (2003) Keys to the Case-bearing Caddis Larvae of Britain and Ireland 2003, 259pp.

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PLATES

n of the Triogue River col

itream of the River TI iogi ue

nfluei ice.

confluei nce.

the flows under :iver. The Triogue River footbridge. This picture was taken following a rainfall event in September 2008 and storm water runoff in the River Triogue is apparent.

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*ded at the sites ir ivesti! jated both recoi upstream and downstream of the Triogue ' Riier confluence during the September 2008 assessment.

Plate 5 New WwTP under construction October 2008.

TP. old town area before circulatingthough the treatment system.

This will store storm water ' from the

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the TI *iogi Je R liver.

Plate 7 The Triogue River downstream of the Portlaoise WwTP outfall. It was considered that water quality in this river may already be benefiting from the upgraded plant as parts of the new scheme are being commissioned.

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!I

APPENDIX I NPWS Site Synopsis SITE SYNOPSIS SITE NAME: RIVER BARROW AND RIVER NORE SITE CODE: 002162

This site consists of the freshwater stretches of the Barrow/Nore River catchments as far upstream as the Slieve Bloom Mountains and it also includes the tidal elements and estuary as far downstream as Creadun Head in Waterford. The site passes through eight counties - Offaly, Kildare, Laois, Carlow, Kilkenny, Tipperary, Wexford and Waterford. Major towns along the edge of the site include Mountmellick, Portarlington, Monasterevin, Stradbally, Athy, Carlow, Leighlinbridge, Graiguenamanagh, New Ross, Inistioge, Thornastown, Callan, Bennettsbridge, Kilkenny and Durrow. The larger of the many tributaries include the Lerr, Fushoge, Mountain, Aughavaud, Owenass, Boherbaun and Stradbally Rivers of the Barrow and the Delour, Dinin, Erkina, Owveg, Munster, Arrigle and King’s Rivers on the Nore. Both rivers rise in the Old Red Sandstone of the Slieve Bloom Mountains before passing through a band of Carboniferous shales and sandstones. The Nore, for a large part of its course, traverses limestone plains and then Old Red Sandstone for a short stretch below Thomastown. Before joining the Barrow it runs over intrusive rocks poor in silica. The upper reaches of the Barrow also runs through limestone. The middle reaches and many of the eastern tributaries, sourced in the Blackstairs Mountains, run through Leinster Granite. The southern end, like the Nore runs over intrusive rocks poor in silica. Waterford Harbour is a deep valley excavated by glacial floodwaters when the sea level was lower than today. The coast shelves quite rapidly along much of the shore.

The site is a candidate SAC selected for alluvial wet woodlands and petrifying springs, priority habitats on Annex I of the E.U. Habitats Directive. The site is also selected as a candidate CSAC for old oak woodlands, floating river vegetation, estuary, tidal mudflats, Salicornia mudflats, Atlantic salt meadows, Mediterranean salt meadows, dry heath and eutrophic tall herbs, all habitats listed on Annex I of the E.U. Habitats Directive. The site is also selected for the following species listed on Annex I I of the same directive - Sea Lamprey, River Lamprey, Brook Lamprey, Freshwater Pearl Mussel, Nore Freshwater Pearl Mussel, Crayfish, Twaite Shad, Atlantic Salmon, Otter, Vertigo rnoulinsiana and the plant Killarney Fern.

Good examples of Alluvial Forest are seen at Rathsnagadan, Murphy’s of the River, in Abbeyleix estate and along other shorter stretches of both the tidal and freshwater elements of the site. Typical species seen include Almond Willow (Salix triandra), White Willow (S. alba), Grey Willow (S. cinerea), Crack Willow (S. fragilis), Osier (S. virninalis), with Iris (Iris pseudacorus), Hemlock Water-dropwort (Oenanthe crocata), Angelica (Angelica sylvestris), Thin-spiked Wood-sedge (Carex sfrigosa), Pendulous Sedge (C. pendula), Meadowsweet (filipendula ulrnaria), Valerian (Valeriana officinalis) and the Red Data Book species Nettle- leaved Bellflower (Campanula frachelium). Three rare invertebrates have been recorded in this habitat at Murphy’s of the River. These are: Neoascia obliqua (Diptera: Syrphidae), Tetanocera freyi (Diptera: Sciomyzidae) and Dictya urnbrarum (Diptera: Sciomyzidae).

A good example of petrifying springs with tufa formations occurs at Dysart Wood along the Nore. This is a rare habitat in Ireland and one listed with priority status on Annex I of the EU Habitats Directive. These hard water springs are characterised by lime encrustations, often associated with small waterfalls. A rich bryophyte flora is typical of the habitat and two diagnostic species, Cratoneuron cornmutaturn var. cornmutaturn and Eucladiurn verticillaturn, have been recorded.

The best examples of old Oak woodlands are seen in the ancient Park Hill woodland in the estate at Abbeyleix; at Kyleadohir, on the Delour, Forest Wood House, Kylecorragh and Brownstown Woods on the Nore; and at Cloghristic Wood, Drummond Wood and Borris Demesne on the Barrow, though other patches occur throughout the site. Abbeyleix Woods is a large tract of mixed deciduous woodland which is one of the only remaining true ancient woodlands in Ireland. Historical records show that Park Hill has been continuously wooded since the sixteenth century and has the most complete written record of any woodland in the country. It supports a variety of woodland habitats and an exceptional diversity of species

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including 22 native trees, 44 bryophytes and 92 lichens. It a!so contains eight indicator species of ancient woodlands. Park Hill is also the site of two rare plants, Nettle-leaved Bellflower and the moss Leucodon sciuroides. It has a typical bird fauna including Jay, Long- eared Owl and Raven. A rare invertebrate, Mitostoma chrysomelas, occurs in Abbeyleix and only two other sites in the country. Two flies Chrysogaster virescens and Hybomitra muhlfeldi also occur. The rare Myxomycete fungus, Licea minima has been recorded from woodland at Abbeyleix.

Oak woodland covers parts of the valley side south of Woodstock and is well developed at Brownsford where the Nore takes several sharp bends. The steep valley side is covered by Oak (Quercus spp.), Holly (Ilex aquifolium), Hazel (Corylus avellana) and Birch (Betula pubescens) with some Beech (Fagus sylvatica) and Ash (Fraxinus excelsior). All the trees are regenerating through a cover of Bramble (Rubus fruticosus agg.), Foxglove (Digitalis purpurea) Wood Rush (Luzula sylvatica) and Broad Buckler-fern (Dryopteris dilatata).

On the steeply sloping banks of the River Nore about 5 km west of New Ross, in County Kilkenny, Kylecorragh Woods form a prominent feature in the landscape. This is an excellent example of a relatively undisturbed, relict Oak woodland with a very good tree canopy. The wood is quite damp and there is a rich and varied ground flora. At Brownstown a small, mature Oak-dominant woodland occurs on a steep slope. There is younger woodland to the north and east of it. Regeneration throughout is evident. The understorey is similar to the woods at Brownsford. The ground flora of this woodland is developed on acidic, brown earth type soil and comprises a thick carpet of Bilberry (Vaccinium mydillus), Heather (Calluna vulgaris), Hard Fern (Blechnum spicant), Cowwheat (Melampyrum spp.) and Bracken (fferidium aquilinum).

Borris Demesne contains a very good example of a semi-natural broad-leaved woodland in very good condition. There is quite a high degree of natural re-generation of Oak and Ash through the woodland. At the northern end of the estate Oak species predominate. Drummond Wood, also on the Barrow, consists of three blocks of deciduous woods situated on steep slopes above the river. The deciduous trees are mostly Oak species. The woods have a well established understorey of Holly (Ilex aquifolium), and the herb layer is varied, with Brambles abundant. Whitebeani (Sorbus devoniensis) has also been recorded.

Eutrophic tall herb vegetation occurs in association with the various areas of alluvial forest and elsewhere where the flood-plain of the river is intact. Characteristic species of the habitat include Meadowsweet (Filipendula ulmaria), Purple Loosestrife (Lyfhrum salicaria), Marsh Ragwort (Senecio aquaticus), Ground Ivy (Glechoma hederacea) and Hedge Bindweed (Calystegia sepium). Indian Balsarn (Impatiens glandulifera), an introduced and invasive species, is abundant in places. Floating River Vegetation is well represented in the Barrow and in the many tributaries of the site. In the Barrow the species found include Water Starworts (Callitfiche spp.), Canadian Pondweed (Elodea canadensis), Bulbous Rush (Juncus bulbosus), Milfoil (Myriophyllum spp.), Pofamogefon x nifens, Broad-leaved Pondweed (P. natans), Fennel Pondweed (f. pectinatus), Perfoliated Pondweed (f. perfoliatus) and Crowfoots (Ranunculus spp.). The water quality of the Barrow has improved since the vegetation survey was carried out (EPA, 1996).

Dry Heath at the site occurs in pockets along the steep valley sides of the rivers especially in the Barrow Valley and along the Barrow tributaries where they occur in the foothills of the Blackstairs Mountains. The dry heath vegetation along the slopes of the river bank consists of Bracken (fferidium aquilinum) and Gorse (Ulex europaeus) species with patches of acidic grassland vegetation. Additional typical species include Heath Bedstraw (Galium saxatile), Foxglove (Digitalis purpurea), Common Sorrel (Rumex acetosa) and Bent Grass (Agrostis stolonifera). On the steep slopes above New Ross the Red Data Book species Greater Broomrape (Orobanche rapum-genistae) has been recorded. Where rocky outcrops are shown on the maps Bilberry (Vaccinium mydillus) and Wood Rush (Luzula sylvatica) are present. At Ballyhack a small area of dry heath is interspersed with patches of lowland dry grassland. These support a number of Clover species including the legally protected Clustered Clover (Trifolium glomeratum) - a species known from only one other site in Ireland. This grassland community is especially well developed on the west side of the mud-

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capped walls by the road. On the east of the cliffs a group of rock-dwelling species occur, i.e. English Stonecrop (Sedum anglicum), Sheep's-bit (Jasione montana) and Wild Madder (Rubia peregrina). These rocks also support good lichen and moss assemblages with Ramalina subfarinacea and Hedwigia Ciliata.

Dry Heath at the site generally grades into wet woodland or wet swamp vegetation lower down the slopes on the river bank. Close to the Blackstairs Mountains, in the foothills associated with the Aughnabrisky, Aughavaud and Mountain Rivers there are small patches of wet heath dominated by Purple Moor-grass (Molinia caerulea) with Heather (Calluna vulgaris), Tormentil (Potentilla erecta), Carnation Sedge (Carex panicea) and Bell Heather (Erica cinerea).

Saltmeadows occur at the southern section of the site in old meadows where the embankment has been breached, along the tidal stretches of in-flowing rivers below Stokestown House, in a narrow band on the channel side of Common Reed (Phragmites)

. beds and in narrow fragmented strips along the open shoreline. In the larger areas of salt meadow, notably at Carrickcloney, Ballinlaw Ferry and Rochestown on the west bank; Fisherstown, Alderton and Great Island to Dunbrody on the east bank, the Atlantic and Mediterranean sub types are generally intermixed. At the upper edge of the salt meadow in the narrow ecotonal areas bordering the grasslands where there is significant percolation of salt water, the legally protected species Borrer's Saltmarsh-grass (Puccinellia fasciculata) and Meadow Barley (Hordeum secalinum) (Flora Protection Order, 1987) are found. The very rare Divided Sedge (Carex divisa) is also found. Sea Rush (Juncus maritimus) is also present. Other plants recorded and associated with salt meadows include Sea Aster (Aster tripolium), Sea Thrift (Armeria maritima), Sea Couch (Elymus pycnanthus), Spear-leaved Orache (Atriplex prostrata), Lesser Sea-spurrey (Spergularia marina), Sea Arrowgrass ( Triglochin maritima) and Sea Plantain (Plantago maritima).

Salicornia and other annuals colonising mud and sand are found in the creeks of the saltmarshes and at the seaward edges of them. The habitat also occurs in small amounts on some stretches of the shore free of stones.

The estuary and the other Habitats Directive Annex I habitats within it form a large component of the site. Extensive areas of intertidal flats, comprised of substrates ranging from fine, silty mud to coarse sand with pebbleslstones are present. Good quality intertidal sand and mudflats have developed on a linear shelf on the western side of Waterford Harbour, extending for over 6 km from north to south between Passage East and Creadaun Head, and in places are over 1 km wide. The sediments are mostly firm sands, though grade into muddy sands towards the upper shore. They have a typical macro-invertebrate fauna, characterised by polychaetes and bivalves. Common species include Arenicola marina, Nephtys hombergii, Scoloplos armiger, Lanice conchilega and Cerastoderma edule.

The western shore of the harbour is generally stony and backed by low cliffs of glacial drift. At Woodstown there is a sandy beach, now much influenced by recreation pressure and erosion. Behind it a lagoonal marsh has been impounded which runs westwards from Gaultiere Lodge along the course of a slow stream. An extensive reedbed occurs here. At the edges is a tall fen dominated by sedges (Carex spp.), Meadowsweet, Willowherb (Epilobium spp.) and rushes (Juncus spp.). Wet woodland also occurs. This area supports populations of typical waterbirds including Mallard, Snipe, Sedge Warbler and Water Rail.

The dunes which fringe the strand at Duncannon are dominated by Marram grass (Ammophila arenaria) towards the sea. Other species present include Wild Sage (Salvia verbenaca), a rare Red Data Book species. The rocks around Duncannon ford have a rich flora of seaweeds typical of a moderately exposed shore and the cliffs themselves support a number of coastal species on ledges, including Thrift (Armeria maritima), Rock Samphire (Crithmum maritimum) and Buck's-horn Plantain (Plantago coronopus).

Other habitats which occur throughout the site include wet grassland, marsh, reed swamp, improved grassland, arable land, quarries, coniferous plantations, deciduous woodland, scrub and ponds.

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Seventeen Red Data Book plant species have been recorded within the site, most in the recent past. These are Killarney Fern (Trichomanes speciosum), Divided Sedge (Carex divisa), Clustered Clover (Trifolium glomerafum), Basil Thyme (Acinos arvensis), Hemp nettle (Galeopsis angusfifolia), Borrer’s Saltmarsh Grass (Puccinellia fasiculafa), Meadow Barley (Hordeum secalinum), Opposite-leaved Pondweed (Groenlandia densa), Autumn Crocus (Colchicum autumnale), Wild Sage (Salvia verbenaca), Nettle-leaved Bellflower (Campanula frachelium), Saw-wort (Serratula tinctoria), Bird Cherry (Prunus padus), Blue Fleabane (Erigeron acer), Fly Orchid (Ophrys insectifera), Broomrape (Orobanche hederae) and Greater Broomrape (Orobanche rapum-genistae). Of these the first nine are protected under the Flora Protection Order 1999. Divided Sedge (Carex divisa) was thought to be extinct but has been found in a few locations in the site since 1990. In addition plants which do not have a very wide distribution in the country are found in the site including Thin-spiked Wood-sedge (Carex sfrigosa), Field Garlic (Allium oleraceum) and Summer Snowflake (Leucojum aesfivum). Six rare lichens, indicators of ancient woodland, are found including Lobaria laefevirens and L. pulmonaria. The rare moss Leucodon sciuroides also occurs.

The site is very important for the presence of a number of EU Habitats Directive Annex II animal species including Freshwater Pearl Mussel (Margarififera margarififera and M. m. durrovensis), Freshwater Crayfish (Ausfropofamobius pallipes), Salmon (Salmo salar), Twaite Shad (Alosa fallax fallax), three Lamprey species - Sea (Petromyzon marinus), Brook (Lampefra planer0 and River (Lampefra fluviafilis), the marsh snail Vertigo moulinsiana and Otter (Lufra lufra). This is the only site in the world for the hard water form of the Pearl Mussel M. m. durrovensis and one of only a handful of spawning grounds in the country for Twaite Shad. The freshwater stretches of the River Nore main channel is a designated salmonid river. The Barrow/Nore is mainly a grilse fishery though spring salmon fishing is good in the vicinity of Thomastown and lnistioge on the Nore. The upper stretches of the Barrow and Nore, particularly the Owenass River, are very important for spawning.

The site supports many other important animal species. Those which are listed in the Irish Red Data Book include Daubenton’s Bat (Myofis daubentono, Badger (Meles meles), Irish Hare (Lepus fimidus hibernicus) and Frog (Rana temporaria). The rare Red Data Book fish species Smelt (Osmerus eperlanus) occurs in estuarine stretches of the site. In addition to the Freshwater Pearl Mussel, the site also supports two other freshwater Mussel species, Anodonta anatina and A. cygnea.

The site is of ornithological importance for a number of E.U. Birds Directive Annex I species including Greenland White-fronted Goose, Whooper Swan, Bewick’s Swan, Bartailed Godwit, Peregrine and Kingfisher. Nationally important numbers of Golden Plover and Bar-tailed Godwit are found during the winter. Wintering flocks of migratory birds are seen in Shanahoe Marsh and the Curragh and Goul Marsh, both in Co. Laois and also along the Barrow Estuary in Waterford Harbour. There is also an extensive autumnal roosting site in the reedbeds of the Barrow Estuary used by Swallows before they leave the country.

Landuse at the site consists mainly of agricultural activities - many intensive, principally grazing and silage production. Slurry is spread over much of this area. Arable crops are also grown. The spreading of slurry and fertiliser poses a threat to the water quality of the salmonid river and to the populations of Habitats Directive Annex II animal species within the site. Many of the woodlands along the rivers belong to old estates and support many non- native species. Little active woodland management occurs.

Fishing is a main tourist attraction along stretches of the main rivers and their tributaries and there are a number of Angler Associations, some with a number of beats. Fishing stands and styles have been erected in places. Both commercial and leisure fishing takes place on the rivers. There is net fishing in the estuary and a mussel bed also. Other recreational activities such as boating, golfing and walking, particularly along the Barrow towpath are also popular. There is a golf course on the banks of the Nore at Mount Juliet and GAA pitches on the banks at lnistioge and Thomastown. There are active and disused sand and gravel pits throughout the site. Several industrial developments, which discharge into the river, border the site. New

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Ross is an important shipping port. Shipping to and from Waterford and Belview ports also passes through the estuary.

The main threats to the site and current damaging activities include high inputs of nutrients into the river system from agricultural run-off and several sewage plants, overgrazing within the woodland areas, and invasion by non-native species, for example Cherry Laurel and Rhododendron (Rhododendron ponticurn). The water quality of the site remains vulnerable. Good quality water is necessary to maintain the populations of the Annex II animal species listed above. Good quality is dependent on controlling fertilisation of the grasslands, particularly along the Nore. It also requires that sewage be properly treated before discharge. Drainage activities in the catchment can lead to flash floods which can damage the many Annex I I species present. Capital and maintenance dredging within the lower reaches of the system pose a threat to migrating fish species such as lamprey and shad. Land reclamation also poses a threat to the salt meadows and the populations of legally protected species therein.

Overall, the site is of considerable conservation significance for the occurrence of good examples of habitats and of populations of plant and animal species that are listed on Annexes I and I1 of the E.U. Habitats Directive respectively. Furthermore it is of high conservation value for the populations of bird species that use it. The occurrence of several Red Data Book plant species including three rare plants in the salt meadows and the population of the hard water form of the Pearl Mussel which is limited to a 10 km stretch of the Nore, add further interest to this site.

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I

APPENDIX 2 Water Quality Monitoring data

Table A2.1 Limits for physiochemical values taken in this report to suggest elevated levels. These limits are based on values provided in EPA (2001). Some of these criteria may be low and do not represent mandatory limits for one off samples. However chronic exceedance above these limits would be considered to be harmful to aquatic ecology and fisheries.

Parameter I Limit value DH .=6 or >9 Conductivity (pS cm-') none Total Suspended Solids I >25 mg/l

Dissolved Oxygen (%) Temperature ("C) >21.5

Dissolved Oxygen (mg <9 c70 or > I 30

Total ammonia (mg N I-') >0.1 (or >0.3)

Un-ionised ammonia >0.02

>2 (mg NH3 I-') Nitrate as NO3 mg/l

>0.01

yrtho-phosphate (mg P I- B0.03

Total Phosphorous :*0.062

Total Alkalinitv none CaCO, Total Hardness (mgll) none

Standard Salmonid Water Regulations (1988)

EPA (2001) Salmonid Water Regulations (1988)

Salmonid Water Regulations (1 988) Salmonid Water Regulations (1988) Salmonid Water Regulations (1 988)

Level for salmonid fish in the EU Freshwater Fish Directive 78/659/EEC.

Salmonid Water Regulations (1988) limit value is 5mg/l.

Strict value taken from EPA (2001), levels above 0.3 mg/l would be

harmful. However, EPA (2001) notes that these limits may be unduly low in certain circumstances. Limit of 1 mg/l given in Salmonid Water Regulations

(1 988). Salmonid Water Regulations (1 988)

This is a strict limit value suggested in Lucey (2007) for protecting sensitive

aquatic species. Limit of 1.7mg/l required to protect Pearl Mussels. Limit

of 50 mg/l given in Surface water Reaulations (1 989).

Strict value taken from Freshwater Fish Directive 78/659/EEC for salmonids.

Value of 0.05 given in Salmonid Water Regulations (1988)

Interim statutory standard for unpolluted rivers (EPA, 2001)

Standard taken for Triogue is 0.07 mgll Level suggested for salmonid waters to

reduce eutrophication (EPA, 2001) EPA (2001 )

EPA (2001)

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Downstream 10 2.03 0.24 6.25 1.94 3.76 1.20 - Upstream 10 0.64 0.06 4.44 1.36 1.85 0.84

Table A2.2 Summary of Laois County Council water quality monitoring data for the River Triogue upstream and downstrearn of the Portlaoise WwTP oufflow during the period November 2006 to September 2007.

NH3

N Mean Min Max St.Dev. Variance 95% C.I.

BOD

N Mean Min Max St.Dev. Variance 95% C.I. I

Downstream 9 2.78 1 .oo 5.00 1.20 1.44 0.79 Upstream 10 1.70 1 .oo 3.00 0.67 0.46 0.42

Conductivity

Downstream 10 748.30 540.00 896.00 106.75 11396.23 66.17 Upstream 10 640.20 497.00 764.00 71.02 5043.73 44.02

DO _ _

I I N . . Mean Min Max St.Dev. Variance 95% C.I. Downstream 10 7.00 2.78 10.71 2.34 5.46 1.45 Upstream 10 8.51 4.20 12.60 2.46 6.06 1.53

Nitrates . . . -. - - - -

N Mean Min 8 Max St.Dev. Variance 95% C.I. I

Downstream 10 4.33 2.36 5.70 1.04 1.09 0.65 Upstream 10 3.67 0.1 7 5.20 1.55 2.39 0.96

Orthoohosohate I - - I- - --

I I N "can Min ~ Max St.Dev. Variance 95% C.I. Downstream 9 0.18 0.06 0.36 0.1 1 0.01 0.07

Upstream 9 0.06 0.03 0.21 0.06 0.00 0.04

aH I-- -

N Mean Min Max St.Dev. Variance 95% C.I. I Downstream 9 8.02 7.82 8.27 0.13 0.02 0.08 Upstream 9 8.1 5 7.92 8.54 0.1 7 0.03 0.1 1

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Table A2.3 Summary of EPA water quality results showing overall results for the Barrow and Triogue Rivers. Data is from EPA biological surveys during the period 2001-2003 (adapted from Toner et a/, 2005).

Sampling 14 IB1 0110500 Station Station Name Barranagh's Bridge, 300m uls of

Triogue River confluence

*Note that the sites immediately downstream of the Portlaoise WwTP (i.e. Kyle Bridge) were not

-1 4 1B1010600 *

1 .

Portnahinch Bridge, 2 km d1s of the% Triogue River confluence

sampled during 2003.

1971 1974 1976 1978 1980 1986 1989 1994 1997 2000 2003

Table A2.4 River Barrow (EPA code 14/8/01) Biological Quality Ratings (Q values) from two sites (one ca. 1 km u/s and another 2 km d/s of the Triogue River confluence), adapted from Clabby et a/, 2004).

Q3-4 4 Q3-4 3-4 Q3 4 Q3-4 3-4 Q4 4 Q4 4 Q4 4 Q3-4 4 Q3-4 4 Q3-4 3-4 Q3-4 3-4

Table A2.5 River Triogue (EPA code 14/T/01) Biological Quality Ratings (Q values) from the five sites monitored by the EPA, adapted from Clabby et a/, 2004). Station 14/T/0100 and 14/T/0200 are upstream and downstream of Portlaoise, respectively.

conf (Triogue

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Table A2.6 Selected water quality parameters from Station No. 0500 (BarranaghWBorness Bridge) on the River Barrow approximately 1 km upstream of the Triogue River confluence. Results are from sampling undertaken by the EPA in 2006 (Neill, 2007).

Table A2.7 Selected water quality parameters from Station No. 0500 (BarranaghWBorness Bridge) on the River Barrow, approximately 1 km upstream of the Triogue River confluence. Results are from sampling undertaken by the EPA in 2007 (Neill, 2008).

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Table A2.8 Selected water quality parameters from Station No. 0550 (Bridge SE of Hammerlane, Bridge u/s Portnahinch Bridge), approximately 0.7 km downstream of the Triogue River confluence. Results are from sampling undertaken by the EPA in 2006 (Neill, 2007).

NH3 Nitrite mg/l N Nitrate mg/l N Chloride mg/l CI

0.019 0.025 0.021 0.074 0.110 0.076 0.200 0.075 3.2 4.1 4.5 4.4 2.9 3.1 2.3 3.5 23 27 25 28 49 40 34 32.28

Table A2.9 Selected water quality parameters from Station No. 0550 (Bridge SE of Hammerlane, Bridge u/s Portnahirich Bridge), approximately 0.7 km downstream of the Triogue River confluence. Results are from sampling undertaken by the EPA in 2007 (Neill, 2008).

Unionised Ammonia mgll NH3 Nitrite mgll N

24.2

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.. ... . . ......... .... . .. .. .. .~ .... .... .... ....... ...................... .......

Table A2.10 Selected water quality parameters from Station No. 0160 on the Triogue River, uls of the Portlaoise STW discharge. Results are from sampiing undertaken by the EPA in 2006 (Neill, 2007) and 2007 (Neill, 2008).

Table A2.11 Selected water quality parameters from Station No. 01 70 on the Triogue River, d/s of the Portlaoise S W discharge in 2006 and 2007. Results are from sampling undertaken by the EPA in 2006 (Neill, 2007) and 2007 (Neill, 2008).

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APPENDIX 3 Biological water quality monitoring September 2008

Upstream of Triogue confluence

Table A3.1 Location and physical characteristics of the control and receptor sites on the river Barrow upstream and downstream of the River Triogue confluence.

Downstream , of Triogue confluence

Location 20 meters upstream of Barrow Triogue confluence

NOS Grid Reference N47368 09769

Approximately 120 meters downstream of the Barrow Triogue confluence N47563 09832

Wetted width (m) - 8 Mean depth (m) 90 Rock 10 Cobble 15 Gravel 15 Fine 60

Table A3.2 Macroinvertebrates recorded during the kick sampling surveys on the River Barrow of a site upstream and a site downstream of the River Triogue confluence in September 2008.

9 1 5 10 70 15

Grouplorganism

4

MAYFLIES (Uniramia,

Polycentropus kingi

Pollution Functional Relative abundance sensitivity a group group Upstream I Downstream

I

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Grouplorganism

h > 1 b

Pollution Functional Relative abundance sensitivity group ,

group . Upstream I Downstream

Potamopyrgus jenkinsi MUSSELS (Mollucsa, 1

Craneflies (Tipulidae) Dicronata sp. BEETLES (Coleoptera) Whirligig beetles (Gyrinidae) Indeterminate larvae Common whirligig beetle Gyrinus substriatus Crawling water beetles

Filtering 1

collector . c Shredder , I 1

C Shredder 2 1

C Predator C Predator 2 2 C Predator 7

Present (1 or 2 individuals), ScarcelFew (<I%), Small Numbers (<5%), Fair Numbers (5- 1 O%), Common (1 0-20%), Numerous (25-50%), Dominant (50-75%), Excessive (>75%).

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1

ll ASTP Avera eScore erTaxon TBI Trent Biotic index Chandler Index score

Portlaoise WwTP Appropriate Assessment .........................................................................................................................................

i rn Ic ted 6.5 4.9

7 33.9

Table A3.3 BMWP, Trent Biotic Index and Chandler Score results for the two sites surveyed during September 2008.

Site Dominant FFG (%) PIR Heterotrophy Vs Autotrophy

Table A3.6 Functional Group characteristics of the two survey sites. Dominant FFG (%) (Dominant group and its relative %); P/R (ratio of grazers to total collectors + shredders, a surrogate for ratio of gross primary production to community respiration); Heterotrophy vs Autotrophy based on a P/R threshold of > 0.75 = autotrophic) (Rabenil et a/, 2005).

Upstream of Triogue confluence 1 Grazer (37.6%) I 0.884 [ Autotrophic onfluence 1 Shredder (54.6%) I 0.288 I Heterotrophic

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Appendix 4 Assessment of Ompacts and Impact Significance

Neutral No effect. Negative The change is likely to adversely affect the ecological value of the feature.

Criteria for assessing impact type and magnitude are presented in Tables A6.1 and A6.2, respectively.

In assessing the magnitude and significance of impacts it is important to consider the value of the affected feature, this is taken into account in Table A2.2.

Table A4.1. Criteria for assessing irnpact type.

I Impact type I Criteria 1 II Positive impact: A change is likely to improve the ecological feature in terms of its I I ecoloaical value.

Table A4.2 Criteria for assessing impact magnitude.

lllmP,aCt ma nitude

I F Minor Impact:

Impact:

Substantial Impact:

Major Impact:

Definition 1 $ 3

~~

No discernible change in the ecology of the affected feature. A change in the ecology of the affected site, the consequences of which are strictly limited to within the development boundaries. A change in the ecology of the affected site which has noticeable ecological consequences outside the development boundary, but these consequences are not considered to significantly affect the distribution or abundance of species or habitats of conservation importance. A change in the ecology of the affected site which has noticeable ecological consequences outside the development boundary. These consequences are considered to significantly affect the distribution and/or abundance of species or habitats of conservation importance. A change in the ecology of the affected site which has noticeable ecological consequences outside the development boundary. These consequences are considered to significantly affect species or habitats of high conservation importance and to potentially affect the overall viability ofthose species or habitats in the wider area. A change in the ecology of the affected site which has noticeable ecological consequences outside the development boundary. These consequences are considered to be such that the overall viability of species or habitats of high conservation importance in the wider area2 is under a very high degree of threat (negative impact) or is likely to increase markedly (positive impact).

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portlaoise waste water treatmthe site synopsis for the affected sac is included as appendix i to...

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