This report has been cleared for submission to the Licensing Director

Signe uwiC;t u F CLIMATE, LICENSING

& RESOURCE USE I Envimnmenhl Protection Agency

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1 To: DIRECTORS

From: Ewa Babiarczyk Environmental Licensing Programme

I/ Date: 26 May 2010

Application for a Waste Water Discharge Licence from Carlow County Council, for the agglomeration named Myshall, Reg. No. D0390-01

1 RE:

Schedule of discharge licensed:

Licence application received:

Notices under Regulation 18(3)(b) issued:

Information under Regulation 18(3)(b) received :

Site notice check:

Site visit

Submission(s) received:

Discharges from agglomerations with a population equivalent of 500 to 1,000

22nd June 2009

2nd October 2009

3rd November 2009, 20th November 2009

14th July 2009

None

One submission received

1. Agglomeration The village of Myshall is situated approximately 33 km southeast of Carlow Town at the foot of the Blackstairs Mountains. The village is served by the Myshall waste water treatment plant W P ) which discharges to the Douglas River. The estimated current population equivalent (p.e.) of the agglomeration is 500. The original WWTP in Myshall was built in 1976 with a capacity of 250 p.e. However, this plant had become overloaded and a new WWTP, with a design capacity of 800 p.e., was constructed 300 m north of the original plant. The new plant was commissioned in April 2007, with the exception of a tertiary treatment system, which was commissioned during summer of 2009. The new plant consists of:

an inlet screen with by-pass-manual stainless screen, wash water and automatic sampler,

grit classifier and blower, aeration tank with aeration wheel, D.O. probe and ferric sulphate dosing point, final settling tank with half bridge scraper and scum pump, forward feed pumping station, Return activated sludge (RAS)NVaste activated sludge (WAS) pumps, tertiary treatment consisting of sand filtration, ferric dosing system, sludge holding tanks, and; storm water holding tank with capacity to hold 3DWF for 2 hours.

Parameter

BOD

At present, planning permission has been granted for 30 units (90% domestic and 10% non-domestic) that have not yet been constructed. Even though it is estimated that this would add another 90 p.e. loading to the WVVTP, the total future p.e. would still be below the plant’s design capacity.

Specifications for the Myshall WWTP

10 mgll

2. Discharges to waters The final effluent discharges through a 225 mm internal diameter pipe to the Douglas River at the primary discharge point (SWI) located at the M P . There are no secondary discharges within the agglomeration and the storm water outfall (SW2) discharges via the primary discharge pipe and at the same location as the final effluent.

All inlet flows are screened and de-gritted. Any storm water flow above 3DWF overflows to the storm water holding tanks. The storage volume of these tanks is 35 m3 and 24 m3. If the tanks reach their capacity then settled, screened and de-gritted storm water overflows to the receiving water, via a baffled overflow pipe. The remaining storm water in the tanks is returned to the forward feed pumping station and pumped back through the plant, as inlet flows permit. There are no pumping stations in the Myshall agglomeration.

The applicant has stated in their application that the plant has been designed to achieve the following final effluent standards:

Table 2.1 Specifications for the Myshall WWTP

I Suspended Solids I I Ammonia I 5 mgll I I Total Phosphorous I 1 mgll I

Note 1 : Design standards for final effluent at 95%ile flow.

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3. Receiving waters and impact The following table summarises the main considerations in relation to the river downstream of the primary discharge. Table 3.1 Receiving waters

Characteristic

Receiving water name and type Resource use

Amenity value

Applicable Regulations

EPA monitoring stations

Biological quality rating (Q value) Target Q

WFD status

WFD Risk Category

WFD protected areas

Classification

The Douglas River (primary discharge SWl) None

Local amenity value

EQS Regulations Note ’

Station No. 12D030100

No upstream monitoring station

Q3-4

Q4

Moderate

l a

None on the Douglas River

Comment

A tributary of the Slaney River.

No downstream drinking water abstraction points on the Douglas River. The nearest abstraction is located on the Slaney River at Clonhasten c. 49 km downstream of the primary discharge from the Myshall WWTP.

Not a designated salmonid river however it serves as spawning ground for salmon.

Not designated as either a Salmonid River or Sensitive Water.

~ ~

Located on the Douglas River c. 680 m downstream of SWI.

Slightly polluted water quality.

Unpolluted water quality.

At risk of not achieving good status.

The closest candidate Special Area of Conservation (cSAC) is the Slaney River Valley, c. 12.4 km downstream from the primary discharge.

Note 1 : European Communities Environmental Objectives (Surface waters) Regulations, 2009 (S.I. No. 272 of 2009)

The Douglas River is a c. 15 km long stretch of river and flows in a northerly and then easterly direction. Under the WFD the location of the primary discharge from the Myshall WWTP is included within the area which has a moderate water quality and is at risk of not achieving good water quality status by 2015. The Douglas River joins the Slaney River c. 12.4 km downstream from the primary discharge point.

The Slaney River is designated as a candidate Special Area of Conservation (cSAC) (site code: 000781). Several populations of pearl mussels (Margaritifera margaritifera) have been recorded in the Slaney River channel downstream of the confluence with the Douglas River. It was stated in the appropriate assessment, submitted as part of the application, that the discharges from the Myshall WWTP are not likely to significantly affect

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Parameter PE Background (mean) concentration

[mg/ll [ms4

Available Proposed ELVs Contribution Predicted Relevant capacity for discharge from primary downstream standard

[mg/ll % from SWI discharge quality

[m@I [ms/ll [mg/ll

500 BOD (Existing) 0.260 90.00 0.631 0.891 12.6 Note

Note 3

The Assimilative Capacity calculations in Table 3.2 above are based on the existing situation when the estimated (p.e.) served by the Myshall WWTP is 500 and the future conditions when the plant will reach its design capacity of 800 p.e. The calculations take into account the normal volume of the primary discharge at the current and the future loading to the plant, the 95%ile flow rate in the receiving water at the primary discharge

BOD (Proposed)

Suspended Solids (Existing)

Solids Suspended

(Proposed) Total Ammonia (as N) (Existing) Total Ammonia (as N)

800 0.260 90.00 Note 3 1.008 1.268 52.6

525 Note 5 500 1,000 96.00 10 Note 0.583 1.583

800 1 .OOO Note 96.00 0.931 1.931 125 Note5 Note 3

500 0.008 94.29 1 0.064 0.072 10.140

0.008 94.29 1 0.103 0.111 10.140 8oo

(Proposed)

(Existing)

(Proposed)

MRP Note 1 500

MRP Note 1 800

0.005 Note * 93.33 0.6 0.039 0.044 S0.075 Note

0.005 Note 93.33 0.6 0.062 0.067 S0.075

(0.01 3 m3/s), the plant‘s specifications for BOD, Suspended Solids, Ammonia and Total Phosphorous, and the concentrations of these parameters upstream of SWI.

The background upstream concentrations for BOD, Ammonia, and MRP used in the assimilative capacity calculations are based on the Agency’s draft ‘Guidance on General Physico-Chemical Components when Licensing Discharges’. This document states that it is necessary to separate the effect of the discharge from a wastewater treatment plant from impacts in the upstream catchment of a river. Therefore, the discharges should be mass-balanced into a hypothetically clean stretch of river in order to gauge its theoretical impact on a pristine stretch of the river. It is further stated that if the discharge can meet the Good Status or the High Status target, when mass-balanced into a clean river then the plant is of itself capable of meeting the necessary ecological status targets. To check if the proposed wastewater treatment plant is of itself capable of meeting the legal standards in a given situation, the guidance recommends the use of the following National Clean River for Mass-Ballancing concentrations: 0.260 mg/l 0 2 for BOD, 0.008 mg N/I for Ammonia and 0.005 mg P/I for MRP.

The combined approach has been adopted for several parameters when setting emission limit values for the discharges at SWI. The Myshall WWTP’s specifications for BOD, Suspended Solids and Total Phosphorous, outlined in Table 2.1 above, have been retained in Schedule A.?; Primary Waste Water Discharge in the RL. The calculation results in Table 3.2 show that the downstream concentrations of BOD will not exceed the relevant standard for this parameter when its emission limit value (ELV) is set at 10 mg/l. Table 3.2 also shows that the concentration of Suspended Solids in the primary discharge from the plant and downstream of SW1 will be much lower than the ELV for this parameter in salmonid waters. Having regard to the plant‘s design specification for treatment of Total Phosphorous, in order to control levels of Molybdate Reactive Phosphorous (as P) in the primary discharge it is proposed to set the ELV for this parameter at 0.60 mg/l. The plant’s design specification for Total Ammonia (as N) is 5 mg/l, however, such concentration of Ammonia in the primary discharge would contribute to the significant exceedance of the relevant standard of 0.140 mg/l or less downstream of SWI. The monitoring results submitted in the licence application indicate that the plant is capable of treating Total Ammonia to a very high standard. Therefore, it is proposed to set the ELV for this parameter at 1 mg/l.

The ELVs imposed in the Schedule A. I: Primary Waste Water Discharge, the monitoring requirements listed in Schedule B. I: Monitoring of Primary Waste Water Discharge and Schedule B.3: Receiving Wafer Monitoring, and the requirements under Conditions 5.1 (d) to reduce Total Phosphorous loadings in the discharge to the maximum possible extent aim at ensuring a high level of protection for the waterbody and will help to provide an improvement in water quality. However, to achieve good water quality status by 2015 and consequently satisfactory biological conditions downstream of the primary discharge from the Myshall WWTP, a holistic approach to water quality management in the Douglas River is required. This should include effective management of all point source inputs to the waterbody from agriculture or single media licences, and the minimisation of diffuse pollution from agricultural sources. Management of the waterbody must be carried out in accordance with the provisions of the relevant regulations along with the Draft River Basin Management Plan for the South Eastern River Basin District (December 2008).

4. Ambient Monitoring The Applicant’s monitoring results from the locations upstream and downstream of the primary discharge from the Myshall WWTP were taken into consideration when setting emission limit values listed in Schedule A.?: Primary Waste Water Discharge of the RL. Monitoring of the receiving water upstream and downstream of SW1 is included in Schedule B.3: Receiving Water Monitoring of the RL in order to ensure the discharges from the Myshall agglomeration are not having a detrimental effect on the quality of the receiving water.

5. Combined Approach The Waste Water Discharge Authorisation Regulations, 2007 (S.I. No. 684 of 2007) specify that a ‘combined approach’ in relation to licensing of waste water works must be taken, whereby the emission limits for the discharge are established on the basis of the stricter of either or both, the limits and controls required under the Urban Waste Water Treatment Regulations (S.I. No. 254 of 2007) as amended and the limits determined under statute or Directive for the purpose of achieving the environmental objectives established for surface waters, groundwater or protected areas for the waterbody into which the discharge is made. The RL as drafted gives effect to the principle of the Combined Approach as defined in S.I. No. 684 of 2007.

6. Programme of Improvements There is no programme of improvements in place for the Myshall WWTP. The existing plant provides tertiary treatment to all waste waters arising within the agglomeration.

7. Compliance with EU Directives In considering the application, regard was held to the requirements of Regulation 6(2) of the Waste Water (Discharge) Authorisation, Regulations, 2007 (S.I. No. 684 of 2007) notably:

Water Framework Directive 12000/60/EC1 The RL, as drafted, transposes the requirements of the Water Framework Directive. In particular, Condition 3: Discharges provides conditions regulating discharges to waters while Schedule A: Discharges specifies limit values for those substances contained within the waste water discharge. Those limits specified in the RL are determined with the aim of achieving good water quality status by 201 5.

Urban Waste Water Treatment Directive 1911271 /EEC1 The RL as drafted, has regard to the requirements of the Urban Waste Water Treafment Directive. In particular, Condition 3: Discharges provides conditions regulating discharges to waters and Schedule A: Discharges specifies limit values for those substances contained within the waste water discharge.

EC Freshwater Fish Directive 12006/44/EC1

The Douglas River is not a designated salmonid river, however, it is an important salmon spawning tributary of the Slaney River. In order to afford protection to the receiving water and to achieve good status, Condition 3: Discharges provides conditions regulating discharges to waters while Schedule A: Discharges specifies limit values for those substances contained within the waste water discharge.

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Dangerous Substances Directive [2006/11/ECI The applicant has provided sampling results for all of the 19 dangerous substances in the primary discharge for the purposes of the licence application. The sampling was conducted four times for each dangerous substance. The results for tributyltin, copper and zinc exceeded the relevant standards given in the European Communities Environmental Objectives (Surface waters) Regulations, 2009 (S.I. No. 272 of 2009).

Condition 4. I O of the RL requires further testing of the discharges from the treatment plant for the presence of the metals and organic compounds. Additionally, it requires the licensee to investigate the sources of the elevated dangerous substances and take the necessary measures to comply with the limits set in the Environmental Quality Objectives (Surface Water) Regulations, S.I. 272 of 2009) for the discharge of such substances from the waste water works.

The RL as drafted provides a high level of protection for the receiving water by ensuring that all discharges from the agglomeration will be provided with an appropriate level of treatment, as per Condition 3: Discharges and Schedule A: Discharges. However, to achieve good water quality status and consequently satisfactory biological conditions downstream of the plant the holistic approach in relation to water quality management is required. The effective management of all diffuse or point source inputs to the waterbody from agricultural or single media licences must be carried out in accordance with the provisions of the relevant regulations (European Communities (Good Agricultural Practice for Protection of Waters) Regulations 2009 and the Water Pollution Acts, 1977 to 1990) along with the Draft River Basin Management Plan for the South Eastern River Basin District (December 2008).

Birds Directive [79/409/EEC1 & Habitats Directive [92/43/EEC] There is one cSAC, the Slaney River Valley (Site Code: 000781) c. 12.4 km downstream of the primary discharge from the WWTP. This cSAC contains several important habitats such as alluvial wet woodlands, floating river vegetation, estuaries, tidal mudflats and old oak woodlands listed on Annex I of the €.U. Habitats Directive. Additionally, this site supports populations of the following species listed in Annex II of this Directive: Sea Lamprey, River Lamprey, Brook Lamprey, Freshwater Pearl Mussel, Twaite Shad, Atlantic Salmon and Otter.

The applicant carried out an appropriate assessment with respect to the discharges from the Myshall WWTP and their potential effects on this cSAC. It has been recognised in the assessment that the Douglas River may serve as an important waterbody for certain stages of the life cycle of important species such as lamprey and salmon. However, in order for the Douglas River to serve as such a habitat, significant improvements in water quality would need to be achieved through a holistic approach in relation to water quality management. The conclusions of the appropriate assessment state that the relevant conservation objective pertaining to the discharge from the Myshall WWTP must be to avoid impacts from high BOD, suspended solids and nutrients by proper treatment of the effluent before discharge to the river. Furthermore, it is stated that the fact that the Agency’s monitoring results show no biological impact of the discharge from the plant on the receiving waters indicates that this conservation objective is currently being achieved. Also Section 4.2: Cumulative Impacts of the appropriate assessment refers to the 2007 Agency’s Q ratings which show slightly polluted conditions (Q3-4) in the Douglas River upstream of the confluence with the Slaney River, but unpolluted conditions (Q4) in the Slaney River at the first two sites downstream of the discharge from the Douglas River and states that the reduced water quality in the Douglas River was therefore not of a sufficient magnitude to bring the biological water quality of the Slaney River down to unsatisfactory

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condition. Therefore there is not likely to be a significant impact on the cSAC from the discharges from this agglomeration

Drinking Water Abstraction Regulations The nearest drinking water abstraction (Register code: PA1-3300PUB1304) is located on the Slaney River at Clonhasten c. 49 km downstream of the primary discharge from the WWTP. The licence application states that the Myshall WWTP will ensure that the discharged effluent will not have a detrimental effect on the Slaney River in terms of faecal coliforms, salmonella and protozoan pathogen numbers. Additionally, it is stated that the tight specifications for BOD, Suspended Solids, Total Ammonia and Total Phosphorous will ensure a good quality of the discharge from the plant. Therefore any negative impact of the Myshall WVVTP on this abstraction point is not expected.

Environmental Lia bi I it ies Directive [2004/35/EC1 Condition 7.2 of the RL satisfies the requirements of the Environmental Liabilities Directive in particular those requirements outlined in Article 3(1) and Annex II of 2004/35/€C.

8. Submission One submission in relation to this licence application was received from the Eastern Regional Fisheries Board (ERFB) on the 4'h September 2009. The concerns of the ERFB are summarized below:

1. Having regard to the flows of 6 I/s for dry weather flow (DWF) and 13 I/s for 95%ile weather flow in the Douglas River at the primary discharge point from the Myshall WVVTP, the ERFB questions the sustainability of a discharge with such limited dilution during low flow periods to salmonid waters.

Response

The Douglas River discharges to the Slaney River, which is designated as Salmonid Waters in the European Communities (Quality of Salmonid Waters) Regulations, 1988 S.I. No. 29311988, c. 12.4 km downstream of the outfall of the final effluent from the plant. There are number of local tributaries which discharge to the Douglas River downstream of the primary discharge point and which contribute to an increase in the volume of the flow, and thus increased dilutions, in this river before it reaches the Slaney River. Therefore, even though the flow in the Douglas River at the primary discharge point is low, the discharge from the Myshall plant becomes significantly diluted before reaching the Slaney River.

The appropriate assessment highlights that the 2007 EPA Q ratings show slightly polluted conditions (Q3-4) in the Douglas River upstream of the confluence with the Slaney River, but unpolluted conditions (Q4) in the Slaney River at the first two sites downstream of the discharge from the Douglas River. Furthermore, it is stated that the reduced water quality in the Douglas River was therefore not of a sufficient magnitude to bring the biological water quality of the Slaney River down to unsatisfactory condition.

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2. The ERFB requests the Agency to take into account the predictions of significant decreases in low flows associated with global warming when assessing the licence application.

Response The Agency is aware of the fact that that the surface water runoff may reduce in future as a result of climate change. The licence for the Myshall WWTP will undergo a review within six years and any impacts associated with climate change can be addressed at that point.

3. The ERFB has referred to the fact that no improvements were noted in the ecological quality of the Douglas River in 2007 when compared to the 2004 results and that this river is in a generally unsatisfactory ecological condition. Also, the Board has stated that the eutrophication in the Douglas River is suspected to take place as a result of sewage and agricultural activities.

Response The ELVs as set out in the RL ensure a high level of protection for the receiving waterbody. Also, the assimilative capacity calculations in Table 3.2 demonstrate that the downstream concentrations of BOD, Total Ammonia and MRP will be within their relevant standards for the Good Status and the downstream concentration of Suspended Solids will be well below the its standard for salmonid waters. Having regard to the assimilative capacity calculations, the discharge from the Myshall WWTP is not considered to have any significant effect on the quality of the Douglas River. The monitoring results show that the biological quality of this river varies from moderately and slightly polluted to unpolluted. No change in the Q values at any of the monitoring locations during monitoring in 2004 and 2007 indicates that the quality of water in the Douglas River is not altered by the discharge from the plant. As pointed out already, in order to ensure an improvement in water quality and to eliminate the potential for eutrophication, effective management of all diffuse and point source emissions must be carried out in accordance with the provisions of the relevant regulations and the Draft River Basin Management Plan for the South Eastern River Basin District (December 2008).

4. The ERFB refers to the exceedances of Orthophosphate recorded by the applicant downstream of the primary discharge from the plant. The EFRB also adds that while the Douglas River is not designated for salmon under the Habitats Directive it is an important salmon spawning tributary of the Slaney and that biological quality rating from Q3 to Q3-4 is highly unsatisfactory from a fisheries perspective. The Board states that it is imperative that the discharge from the Myshall WWTP achieves Q4, and not less, and does not contribute to unsatisfactory biological conditions downstream from the discharge from the plant.

Response The Agency acknowledges that the results of the downstream ambient monitoring submitted as part of this licence application show the elevated levels of Orthophosphate. In order to control the levels of this parameter, and having regard to the plant’s design specification for Total Phosphorous and to the results of the assimilative capacity calculations, it is proposed to set the ELV for

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concentration of Orthophosphate in the final effluent from the plant at 0.60 mg/l. Also, the Agency recognises that the water quality in the Douglas River is not satisfactory, however, no change in the Q values at any of the monitoring locations during monitoring in 2004 and 2007 indicates that the quality of water in the Douglas River is not altered by the discharge from the Myshall W P . The ELVs as set out in the RL aim at ensuring a high level of protection for this river and will help to provide an improvement in its water quality.

The ELVs imposed in the Schedule A.?: Primary Waste Water Discharge and the monitoring requirements listed in Schedule B. 1: Monitoring of Primary Waste Water Discharge and Schedule B.3: Receiving Water Monitoring of the RL will help to provide an improvement in water quality. To achieve good water quality status and consequently satisfactory biological conditions downstream of the plant the holistic approach in relation to water quality management is required. Therefore, the effective management of all diffuse or point source inputs to the waterbody from agricultural or single media licences must be carried out in accordance with the provisions of the relevant regulations (European Communities (Good Agricultural Practice for Protection of Waters) Regulations 2009 and the Water Pollution Acts, 1977 to 1990) along with the Drafi River Basin Management Plan for the South Eastern River Basin District (December 2008).

9. Cross-office liaison

I contacted Mr. Nigel Hayes in the Agency’s Office of Environmental Enforcement (OEE) who stated that there have been no enforcement actions open against Carlow County Council with regard to the Myshall W P .

Also, supporting information in the form of water quality monitoring data was obtained from the Agency’s Office of Environmental Assessment (OEA) and utilised to augment the application documentation supplied by the applicant.

Advice and guidance issued by the Technical Working Group (TWG) was followed in my assessment of this application. Advice and guidance issued by the TWG is prepared through a detailed cross-office co-operative process, with the concerns of all sides taken into account. The Board of the Agency has endorsed the advice and guidance issued by the TWG for use by licensing Inspectors in the assessment of wastewater discharge licence applications.

10. Site Visit I did not carry out a site inspection of the waste water treatment plant in Myshall during my assessment of the application, but an appropriate site notice check was carried out by the Agency.

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11. Charges The RL sets an annual charge for the agglomeration at €2,316 and is reflective of the monitoring and enforcement regime being proposed for the agglomeration.

12. Recommendation I recommend that a Final Licence be issued subject to the conditions and for the reasons as set out in the attached Recommended Licence.

Signed

Ewa Babiarczyk Inspector Office of Climate, Licensing and Resource Use

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