This Report has been cleared for submission to the Director by r Karen Creed ate: 891//~/&~/ LICENSING & RESOURCE USE. To: DIRECTOR Environmental Licensing From: Jennifer Cope Programme Date: 03 March 201 1 Application for a Waste Water Discharge Licence froin Kildare RE: County Council, for the Derrinturn agglomeration, Reg. No. DU244- 01 * Schedule of discharge licensed: Discharges fi-om agglomerations with a population equivalent of between 1,000 and 2,000. Licence application received: 27 February 2009 Notices under Regulation 18(3)(b) issued: 30 September 2009, 13 August 201 0 Information under Regulation 18(3)(b) received: 3 March 2010,7 May 2010,3 November 2010 Additional Information: 08 February 201 1 Site notice check: 26 March 2009 Site visit: 17 July 2009 Submission(s) Received: None 1. Agglomeration This application relates to the Derrinturn agglomeration. Derrintum is located in the north west of County Kildare approximately 12 km from Clane and 9 km to the east of Edenderry, Co. Offaly. A new waste water treatment plant (WWTP) was commissioned in winter 2009 (260m from the former WWTP). The former WWTP has been demolished. As pai-t of the new WWTP works the primaiy discharge point was relocated from the Ballyshannon river via a rising main to the Cushaling river, approximately 2.3 km fi-om the WWTP. The WWTP is an activated sludge system which provides secondary treatment with nutrient removal. It has a design capacity of 1,600 population equivalent (p.e.) and design effluent quality levels of 8 mg/l BOD, 8 mg/l suspended solids, 0.5 mg/l total phosphorus and 1.5 mg/l ammonia. Based on flow and BOD tests in February 2010 the agglomeration is estimated to be receiving a load of approximately 1,286 p-e., (approximately 1,204 pe., domestic and 82 p.e., non domestic). There are an additional 256 p.e., in developments granted planning permission which have not yet commenced. The applicant estimated the maximum future population equivalent would increase to 1,542 by 2015 I The wastewater collection network serving the agglomeration drains by gravity, apart from a pumping station serving the Ashgrove Estate. The network is a partially separate system. The WWTP comprises of an inlet pumping station, package inlet works - screening & grit removal, package treatment plant - secondary treatment, tertiary sand filter, chemical dosing facilities for precipitation of phosphorus, sludge holding tank, control/administration building and an outlet pumping station. Treated effluent from the WWTP is pumped via a rising main to enter the Cushaling River at Ticknevin, downstream of the confluence with the Ballyshannon river. There is one stormwater tank located at the inlet pumping station. The design dry weather flow (DWF) is 4.17 l/s and the plant has been designed to cater for up to 3 DWF (12.5 l/s). Flows above 3 DWF will be diverted to the storm tank. The storm water tank provides a minimum of 2 hours retention at peak flow (6 DWF). In order to provide this, a minimum capacity of 90 m3 is required. The constructed storm tank provides a capacity of 140 m3 including the storm tank and inlet pumping station. Flows in excess of 6 DWF will be discharged to the adjacent Ballyshannon river at SW-2. The wastewater stored in the storm tank will be re-routed back to the inlet pump station via a noli-return valve upon cessation of high storm flow conditions. Kildare County Council has identified three pumping stations (Ashgrove Estate, WWTP inlet and WWTP final effluent) along the sewer network. 2. Discharges to waters Parameter BOD mg/l Suspended Aininonia 111g/1 Total Phosphorus Ortho-P mg/l Soiids mg/l mg/l Average concentsat ions 3.2 4.8 0.3 0.5 0.28 Note 1 WWTP design 8 8 0.5 standasds 1.5 2 Emergency overflows Kildare County Council has identified three pumping stations within the sewer network. Kildare County Council has identified that there is one emergency overflow, which is associated with the WWTP Final Effluent Pump Station (to rising main discharge), which, if activated, would discharge to the Ballyshannon river adjacent to the WWTP. The emergency overflow would require both a power failure and /or total pump failure to result in a discharge. In the event of a power failure, the on-site emergency generator will provide power to enable pumping and operation of the WWTP to continue. According to the applicant I “as the sump handles final effluent that has been treated to a relatively high degree, it would be reasonable to conclude that the impact upon the receiving waters would not be as significant as that in the event of a storm water overflow. ” Site Inspection An inspection of the Derrinturn agglomeration was carried out on 17 July 2009 and focussed on the former WWTP, the new WWTP, the primary discharge point, the Ballyshannon river and the Cushaling river. At the time of the inspection the new WWTP was undergoing water testing. The new WWTP has a rising main and pump to discharge the effluent to the Cushaling River approximately 2.3 km away. 3. Receiving waters and impact The following table summarises the main considerations in relation to the Cushaling River downstream of the primary discharge. Table 2.0 Receiving waters Characteristic Classification Comment Receiving water name Cushaling river (EPA name: Figile river) (Water body code: IE-SE-14-987) and type Resource use None reported There is no surface water (i.e. drinking) abstraction point identified downstream of the primary discharge point. Amenity value None reported The status of the river is ‘bad’, due to bad ecological status (fish). Applicable Regulations UWWT Regulations Note Compliant (See below) Environmental Objectives Regulations Note Non-compliant (See below) Designations The River Barrow and River Nore SAC The primary discharge does not (site code 2162) discharge directly into a designated site. The Cushaling river flows into the River Figile which is a tributary of the River Barrow. The River Barrow and River Nore SAC is approximately 32 km downstream of the primary discharge. River Cushaling (EPA name: Figile) is not The Cushaling river flows into the designated as a nutrient sensitive river River Figile which is a tributary of the River Barrow, which is a nutrient sensitive river. The River Barrow is approximately 32 km downstream of the primary discharge. EPA monitoring stations There is no upstream monitoring station. 14F0 10050 Approximately 23 5m downstream of sw1-P. Biological quality rating I Downstream (Station ID: 0050 I (QV0 in 1997,Q2-3in 2009) (Q value) WFD status Bad Based on bad ecological (fish) status WFD Risk Catenorv 1 a (at risk of not achieving good status) Date obiective to be achieved: 2021 Cushaling river which is approximately 32 km upstream of the 3 issues downstream of the primary discharge. (42- 3 in 2009). There is no biological data since the new WWTP was installed in winter I 2009. Note 1: Urban Waste Water Treatment Regulations, 2001 and amendments. S.I. No. 254 of 2001. Note 2: European Communities Objectives (Surface Waters) Regulations 2009, S.I. No. 272 of 2009. In winter 2009 the primary discharge point was relocated fiom the Ballyshannon river (which is a tributary of the River Cushaling) via a rising main to the Cushaling river (see Appendix I). The River Cushaling (EPA name: Figile) is seriously polluted (biological rating of 42-3 in 2009) downstream of the primary discharge. I consulted with the Agency’s Office of Environmental Assessment in relation to the latest biological monitoring of the River Figile. The Figile River was in an unsatisfactory ecological condition when surveyed again in 2009. There was no change in status with signs of eutrophication evident at the Jive stations examined. Poor ecological conditions were apparent in the upper reaches (OOSO), the dominance of pollution tolerant macroinvertebrate species, excessive algal growth, heavy siltation and low dissolved oxygen levels (72% saturation) indicated sign @cant ecological disruption. Measures need to be put in place to reduce high background concentrations of BOD, orthophosphate and ammonia in the River Figile (Cushaling) upstream of the primary discharge. The South Eastern River Basin Management Plan (2009-20 15) provides details of recommendations and planned measure to reduce pollution in water courses. In particular, the Figile Water Management Unit Action Plan (2009-2015) identifies measures to protect and restore water status by addressing the main pressures such as waste water treatment plants, industry and agriculture. Under the Figile Water Management Unit Action Plan, the River Figile is required to achieve good status by 2021. In addition, the Figile Water Management Unit Action Plan requires the Derrinturn WWTP to be provided with tertiary treatment or the WWTP outfall to be relocated. The new WWTP with nutrient removal and tertiary treatment was commissioned in winter 2009. The primary discharge point was also relocated fiom the Ballyshannon river to the River Cushaling (approximately 2.3 km from the WWTP). This should improve the quality of the Ballyshannon river and the Cushaling river. However, there is an extremely low number of dilutions available in the River Cushaling at the primary discharge point (SW1-P). Approximately 2 dilutions are available on the basis of normal discharge volume (465 m3/day) and the 95%ile flow (0.011 m3/s) in the River Cushaling. Assimilative Capacity The population equivalent is estimated to increase to 1,542 by 2015 and the design capacity of the plant is 1,600 p.e. I consulted with the Hydrometric section of the EPA who estimated the flow of the river Cushaling at the point of discharge to be 0.01 lm3/s.