WASTE WATER DISCHARGE LICENCE INSPECTORS REPORT D

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1 This Report has been cleared for submission to the Board by Dr. Karen Creed, Senior Inspector Signed: 06/08/2013 U D Mew (inlbkdl OFFICE OF CLIMATE, LICENSING & 1 RESOURCE USE. WASTE WATER DISCHARGE LICENCE INSPECTORS REPORT D To: Directors From: Yvonne English Envi ron menta I Licensing Program me I Date: 6th August 2013 RE: Application for a Waste Water Discharge Licence from North Tipperary County Council, for the agglomeration named Thurles, Reg. No. [DOO Licence application received: received: Notices under Regulation 20(1) issued: 30/03/2009, 26/05/2009, 27/03/2013, 2/04/20 13, 29/04/20 13 received : Site notice check: Fubmission(s) Received: 1. Agglomeration This application relates to the agglomeration named Thurles. Thurles is located in North County Tipperary (See map in Appendix 1). The Thurles waste water treatment plant (WP) was designed to cater for a population equivalent (p.e.) of 15,000. The existing p.e. served by the wastewater works is 10,893. The influent to the wastewater treatment plant is primarily domestic wastewater. Thurles W P currently accepts landfill leachate, however, the total accepted is less than YO of the total plant influent volume. The sewage system in Thurles is a combined system. Page 1 of 9

2 D The WWTP provides secondary treatment with nutrient removal. The plant consists of screening, grit trap, aeration tanks, clarification and phosphorous removal. There is a storm water tank on site which has a storm water overflow, this overflow discharges with the final effluent through the primary discharge point. The plant also includes a sludge processing system (picket fence thickening and centrifuge) prior to recovery off site. 2. Discharges to waters The final treated effluent discharges througn tne primary discharge point (SWOOl) to the River Suir. The normal flow from the Wwrp is 7,978m3/day. The final treated effluent quality from the WWTP in 2011 was within the limits prescribed in the Urban Wastewater Treatment Regulations (BOD 25mg/I, COD 125mg/I, suspended solids 35mg/I, Total Phosphorous 2mg/l, Total Nitrogen 15mg/l). The average effluent monitoring results from January 2012 to March 2013 for BOD, COD and suspended solids were 2.5mg/I, llmg/l and 4.6mg/I, respectively. There are no secondary discharge points within the agglomeration. Thurles Agglomeration contains 5 pumping stations. The Monadreen pumping station and the Willows pumping station both have emergency overflows which discharge to the River Suir. The Archerstown Industrial Estate pumping station has a very low flow rate which flows into the agglomeration sewer network and ultimately flows to the Kavanagh Place pumping station. The Kavanagh Place pumping station and the Brittas Road pumping station both have stormwater overflows and discharge to River Suir. There is also a storm water overflow located at Cathedral Street in the centre of the town and as outlined above there is a storm water tank at the WWTP which has a storm water overflow, this overflow discharges with the final effluent through the primary discharge point. The licence, as drafted, requires that all stormwater overflows must conform to the criteria as set out in the DoECLG Pmcedu~s and Cfltefla in Relation to Stom Water OvefloWS, 1995 and any other guidance as may be specified by the Agency. The programme of infrastructural improvements required under Condition 5.1 of the recommended licence (RL) requires an assessment of all storm water overflows (Condition 5.2.3) and preparation of an implementation plan as necessary (Condition 5.3). Sthedule A; Dixharges & Dixharge Monitoflng of the RL specifies the Emission Limit Values (ELVs) to which the discharge from the Thurles agglomeration must conform. The ELVs are aimed at providing a high degree of protection to the receiving water body. Monitoring of the discharges will take place as per this schedule of the RL. 3. Receiving waters and impact The following table summarises the main considerations in relation to the River Suir downstream of the primary discharge. Page 2 of 9

3 WO2641 Table 1: Receiving waters Characteristic I Classification Receiving water name and type River Suir Applicable Regulations UWWT Regulations - Surface Water Regulations Note * Comment (WFD Code: IE SE ) In compliance In compliance Designations EPA monitoring stations Biological quality rating (Q value) WFD status WFD Risk Category la I Lower River Suir SAC Cabragh Bridge (EPA RS Code: RSl6SO20900) 1 Holycross Bridge (EPA RS Code: RS16S021100) 43-4 (slightly polluted) 43-4 (sliqhtly polluted) Poor SAC (Site code: ) Approximately 0.5km u/s of SWOOl on River Suir Approximately 4km d/s of SWOOl on River Suir Upstream of Wwrp Downstream of WWTP Restore by 2021 At risk of not achieving good status Note 1: Urban Wastewater Treatment Regulations, as amended, Note 2: European Communities Environmental Objectives (Surface Water) Regulations 2009 (as amended). The Suir Upper Water Management Unit Action Plan (WMUAP) identifies the Thurles Wwrp as a point pressure on the Suir Upper catchment. The Office of Environmental Assessment (OEA) have carried out upstream and downstream ambient monitoring on the River Suir for a number of years. The monitoring results indicate that the receiving water is in compliance with the physicochemical conditions of the European Communities Environmental Objectives (Surface Water) Regulations 2009, (as amended). Table 2: Mass Balance Calculations. Parameter proposed ELVs for Contribution Predicted Background discharge Concentration from primary downstream from discharge concentration (mg/l> SWOOl (ms/j) (mg/l) (mq/l) standard (mg/l) BOD Nok ' Orthophosphate Note 1 Total Ammonia Note ' Note 1: European Communities Environmental Objectives (Surface Waters) Regulations 2009, as amended. Mass balance calculations were carried out using the monitoring information provided by OEA, i.e. Aquarius. The 95%ile flow in the river just below the primary discharge is 0.7m3/s. The assimilative capacity calculations are based on the 95%ile flow in the receiving water, the mean background concentration of each parameter in the receiving water, the normal effluent discharge rate and the maximum concentration of the parameter in the effluent (Table 2). Page 3 of 9

4 D The mass balance calculations indicate that the predicted downstream concentrations for BOD, orthophosphate and ammonia are within the standards set in the European Communities Environmental Objectives (Surface Water) Regulations 2009, (as amended) subject to the proposed ELVs. The limit of 0.075mg/1 for orthophosphate, 0.14mg/l for ammonia and 2.6mg/I of BOD in the receiving water are statutory limits set in the European Communities Environmental Objectives (Surface Water) Regulations 2009, (as amended). An ELV of 0.3mg/l is recommended for orthophosphate, 0.5rngll for ammonia and 6mg/l for BOD in the RL. The limits are set based on the mass balance calculations and the achievable standards that can be met with the existing infrastructure at the WWTP. The WWTP has activated sludge treatment. Based on discharge monitoring results submitted by North Tipperary County Council as part of the licence application for the Thurles Wwrp the proposed ELVs are achievable. Effluent monitoring results were submitted for the period February 2012 to February These results show that effluent quality for BOD ranges from 2-3 mg/l, effluent quality for orthophosphate ranges from mg/I and effluent quality for ammonia ranges from mg/l. Improvement works may be required at the WWTP for the constant achievement of the orthophosphate limits set in the RL. 4. Ambient Monitoring Schedule B: Ambient Monitoring of the RL specifies the parameters, analysis method and frequency for which ambient monitoring of the primary discharge shall be carried out. The requirements for ambient monitoring in Schedule B: Ambient Monitoring are sufficient to ensure that there will be no deterioration in the status of the receiving water as a result of the discharge. 5. Combined Approach The Wastewater Discharge (Authorisation) Regulations (2007, as amended) 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 (2001, 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 water body into which the discharge is made. The RL, as drafted, gives effect to the principle of the Combined Approach as defined in Wastewater Discharge (Authorisation) Regulations (2007, as amended). 6. Programme of Improvements The WWTP in Thurles provides secondary treatment with nutrient removal for wastewater from the Thurles agglomeration. Condition 5.1 of the RL requires the licensee to prepare and submit to the Agency a programme of infrastructural improvements to maximise the effectiveness and efficiency of the waste water works. The conditions and emission limit values specified in the RL will ensure no deterioration in the quality of the receiving waters as a result of the discharge. 7. Compliance with EU Directives In considering the application, regard was been had to the requirements of Regulation 6(2) of the Wastewater Discharge (Authorisation) Regulations (2007, as amended) notably: Page 4 of 9

5 Drinkina Wate r Abstraction Reaulations There are no drinking water abstractions downstream of the discharge from the Thurles WWTP. Sensitive Wate rs The River Suir is designated a sensitive area under the UWWT Regulations, 2001 as amended. An ELV for Total Phosphorus has been set in the RD to ensure compliance with these regulations. Water Framework Directive r2000/60/ ECI The RL, as drafted, transposes the requirements of the Water Framework Directive. In particular, Condition 3: Discharges provides conditions regulating discharges to waters. Schdufe A: Dkharges & Dbcbarge Monitoring 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 201s. European Communities Environmental Objectives (Surface Water) Regulations 2009, [as amended] The ambient monitoring data supplied by OEA demonstrates compliance in the receiving water with the European Communities Environmental Objectives (Surface Water) Regulations 2009, (as amended). The RL, as drafted, includes emission limit values to ensure that the treatment provided by the plant is sufficient to satisfy the European Communities Environmental Objectives (Surface Water) Regulations 2009, (as amended). Urban Waste Water Treatment Directive [91/271/EECl Thurles Wwrp complies with the requirements of the Urban Waste Water Treatment Directive, in terms of the level of treatment provided. The RL, as drafted, has regard to the requirements of the Urban Waste Water Treatment Directive. Danaerous Substa nces Directive r2006/11/ec1 The applicant has provided once-off sampling results for 19 of the 19 dangerous substances in the primary discharge for the purposes of the licence application. The measured concentrations are not considered significant. Condition 4.21 of the RL, as drafted, requires the licensee to identify the priority substances for monitoring by undertaking a risk-based assessment in accordance with "Guidance on the SZreening fir Pifority Substances for Waste Water Discharge Licences" issued by the Agency. Monitoring for any identified priority substance shall be carried out as required by the Agency. Birds Directive r79/409/eec1 & Habitats Directive r92/43/eec1 Thurles WWTP discharges directly, into the Lower River Suir SAC'. The site is protected for habitats listed under Annex 1 of the Habitats Directive, including the priority habitats Alluvial Forests and Yew Woods. It is also selected for protection of species listed under Annex I1 of the same directive, including freshwater pearl mussel, white-clawed crayfish, atlantic salmon, otter, twaite shad and three species of lamprey. SAC: Special Area of Conservation designated under the HabRats Dihxfiw, Council Directive 92/43/EEC of 21 May 1992 on the conservation of natural habitats and of wild fauna and flora. Page 5 of 9

6 A screening (Stage 1) for Appropriate Assessment of the discharge from the agglomeration was undertaken to assess, in view of best scientific knowledge and the conservation objectives of the site, if the discharge, individually or in combination with other plans or projects, is likely to have a significant effect on the European Site. It was determined that an appropriate assessment was required. The appropriate assessment indicated that there may be a potential impact on the designated European Site, Lower River Suir SAC (Site Code: ), into which the primary discharge from the agglomeration outfalls. In particular, the contribution of the discharge, in combination with other activities within the catchment, to nutrient enrichment of the River Suir catchment may have implications for the qualifying species: atlantic salmon (Sdmo salar), brook lamprey (Lampeh planen ) and whiteclawed crayfish (Austroptamobius pa/lips). The nearest pearl mussel population downstream of the Thurles Wwrp on the main Suir River channel is over 70km away. Indirect impacts on otter (Lutra lutra) populations may arise as a consequence of reduced prey availability. Habitats identified that may be affected by the discharge include Hydrophilous tall herb fringe communities and Watercourses with Ranunculion fluitantis and Gllittfcho-&trachion vegetation which both occur in the vicinity of the discharge. While Thurles Wwrp is identified as a point pressure in the Suir Upper Water Management Unit Action Plan, it is listed as Priority 3 with the stated measure: Want requiring the investigation of (303. The most recent EPA monitoring results for the River Suir indicate a quality rating of 43-4 ( Moderate ) status in 2011 at Cabragh Bridge (Eden station RS16S020900), approximately 500 metres upstream of the primary discharge from Thurles Wwrp. EPA monitoring results for Holycross Bridge, (Eden station RS16S021100), located approximately 4 kilometres downstream of the discharge, also indicated a 43-4 rating in The Appropriate Assessment concludes that recent upgrades to the Wwrp completed during , which included phosphate reduction, has led to an improvement in the treatment efficiency of the Wwrp and has had an ameliorative effect on ambient phosphate levels in the River Suir discharge. The Appropriate Assessment demonstrates that the d affect the integrity of the European Site subject to th phosphate reduction measures at the Wwrp. The results of ambient monitoring show no deterioration in the water quality of the Lower River Suir SAC, into which the primary discharge outfalls, upstream and downstream of the discharge point. The ELVs set in the licence as drafted will ensure compliance with the European Communities Environmental Objectives (Surface Water) Regulations 2009, (as amended) which will provide a high degree of protection to the receiving water M y. In accordance with the European Communities (Birds and Natural Habitats) Regulations 2011 (S.I. No. 477 of 2011), pursuant to Article 6(3) of the Habitats Directive, the discharge will not adversely affect the integrity, in terms of maintaining favourable conservation status of the qualifying interests of the European Si having regard to its conservation objectives. Skhdule A: Discharges & Di3charge Monibring of the RL specifies the ELVs to wh the discharge from the Thurles agglomeration must conform. The ELVs are aim providing a high degree of protection to the receiving water body. Monitoring discharges will take place as per this schedule of the RL. Condition 4.13 of the RL, as Page 6 of 9

7 D drafted requires the licensee to carry out an investigation for the identification and assessment of storm water overflows and that all storm water ovemows shall be in compliance with the criteria for storm water overflows as set out in the the DoECLG Pmedums and Cdteda in Relation to Storm Water Over#owS, 1995 and any other guidance as may be specified by the Agency. Environmental Impa ct Assessme nt Directive r85/33 7lEECI An Environmental Impact Statement was not required and should one be required as part of any programme of improvements, it will be dealt with as per Condition 1.8 of the RL. Environmental Liabilities Directive r 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 I1 of 2004/35/EC. 8. Cross Office Liaison Advice and guidance issued by the Technical Working Group (lwg) 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. 9. Submissions No submissions were received in relation to this application. 10. Charges The RL sets an annual charge for the agglomeration at 2, and is reflective of the monitoring and enforcement regime being proposed for the agglomeration. 11. Recommendation I recommend that a Finat Licence be issued subject to the conditions and for the reasons as set out in the attached Recommended Licence. Signed Environmental Licensing Programme Page 7 of 9

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