Inspectors Report
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An Bord Pleanála Inspector’s Report WW03.WW0415 DEVELOPMENT:- Description: Licence to Discharge Treated Sewage Effluent from ‘Cois na Sionna’ Housing Development to Lower River Shannon. Address: Main Street, O’Brien’s Bridge, County Clare. PLANNING APPLICATION Type of Application: Licence Review under Section 4 of the Local Government (Water Pollution) Acts 1977 to 2007. Planning Authority Reg. Ref. W.P. 115 Applicant: Tom Kelly Local Authority Decision: Grant Licence Review APPEAL Appellants: Tom Kelly Observers: None Date of Site Inspection: 9/5/14 Inspector: Paul Caprani WW03.WW0415 An Bord Pleanála Page 1 of 23 1.0 INTRODUCTION File no. WW0415 relates to a first party appeal against a number of conditions attached to a review of a licence to discharge treated sewage effluent into the Lower River Shannon from a small housing estate at O’Brien’s Bridge, County Clare. The grounds of appeal argue that a number of conditions attached to the licence are unreasonable and result in a significant financial burden on the licensee. 2.0 SITE LOCATION AND DESCRIPTION O’Brien’s Bridge is a small village straddling the banks of the lower River Shannon and Shannon Canal between Limerick and Killaloe in County Clare. A small residential estate located to the north of the main street of O’Brien’s Bridge is served by a proprietary wastewater treatment system. This estate comprises of 15 houses. An additional house (no. 2) which fronts directly onto Main Street is also served by the proprietary wastewater treatment plant. Thus 16 houses are served in total. The wastewater treatment plant is located in an area of open space within the estate. It comprises of a septic tank and large modular puraflo treatment plant where the effluent is passed through fibrous material where microbial breakdown of the effluent takes place. The treated effluent is then discharged via a sewage pipe which to the River Shannon approximately 150 metres to the south of the site. The outfall from the wastewater treatment plant is located at the Quay wall on the northern side of the River Shannon. At the time of site inspection the discharge pipe was above the water level within the river (see photographs attached). 3.0 APPLICATION Clare County Council initiated a review of the licence issued under the provisions of the Water Pollution Act 1977-2007. An application for a licence to discharge effluent was submitted on 11 th March 2014. The planning application form indicates that Clare County Council originally granted a licence under reg. no. P98/2053. It is stated that the type of effluent being discharged is domestic wastewater only. The wastewater treatment plant serves a population equivalent (PE) of 46. The expected dry weather flow from the wastewater treatment plant is estimated to be just less than 7 cubic metres per day. The maximum WW03.WW0415 An Bord Pleanála Page 2 of 23 volume of effluent to be discharged on any one day is 15 cubic metres. It is stated that the private houses are occupied all year round and therefore no seasonal variability in the discharge is expected. The domestic effluent is discharged into a septic tank with a baffle wall. Following primary settlement, the effluent is then pumped through a Bord na Mona puraflo system which comprises of a peat fibre bio filter with an area of 120 square metres for secondary treatment. There is no tertiary treatment on site. The septic tank is desludged on an annual basis. On 8 th January 2012 a submission was received from Clare County Council from the Department of Arts, Heritage and the Gaeltacht. Clare County Council is advised by the Department that screening for Appropriate Assessment or full Appropriate Assessment will be required as part of the licence review process. It is noted that more stringent requirements than those under the Water Framework Directive may apply in certain cases particularly in relation to the Freshwater Pearl Mussel Regulations. 3.1 Local Authority Assessment A detailed Planning Report was prepared in relation to the licence review. The report notes that the status of the Lower River Shannon is designated as “moderate” under the Shannon River Basin Management Plan. It is also noted that the Lower River Shannon is designated as a Special Area of Conservation (site code 002165) and a Special Protection Area (site code 004077). An Appropriate Assessment screening is attached to the report. The performance associated with the operation of the wastewater treatment facility on the site indicates poor maintenance. While there is a 90% compliance with the BOD licence limit (10mg/l) there is only a 20% compliance for suspended solids (15mg/l). It is considered however that the present limit of 15mg/l in the final effluent discharge is difficult to achieve on an on-going basis therefore a licence limit of 30mg/l is considered more suitable. A technical assessment was carried out using background concentrations in the river taken at Killaloe Bridge approximately 6 kilometres upstream of the discharge point. In terms of assimilative capacity it is stated that there is adequate capacity in this stretch of WW03.WW0415 An Bord Pleanála Page 3 of 23 water to assimilate the discharge from the development. The resultant concentration of pollutions in the River Shannon is less than the standard set out for good status for each pollutant. It is also noted that the discharge utilises less than the recommended 25% of available headroom in the River Shannon. There is sufficient dilution in the River Shannon to assimilate the pollutants of MRP, total ammonia and BOD concentrations. Based on the technical assessment of the receiving waters there is no indication of any impact of this discharge on the quality status of the River Shannon. It is noted that there is a drinking water extraction point downstream of Castleconnell Village, 7 kilometres downstream of the effluent discharge point. Data for the raw water intake for 2012 and 2013 has been assessed to review any potential elevated levels of ammoniacal nitrogen. No deterioration in water quality is noted downstream of the discharge. The assimilative capacity of the receiving waters indicates that very significant dilution rates are available. The mixing of the discharge and the exposure to UV in the 7 kilometre channel between the discharge point and the Castleconnell intake for water abstraction is such that there is no likelihood of issues arising from the intake of this supply. The lower River Shannon is not designated as a sensitive water, a bathing water or is not designated under the Freshwater Fish Directive or the Shellfish Water Directive. The continued discharge is therefore deemed to be appropriate subject to the following emission limit values. o BOD 20mg/l (increased from the old licence limit of 10mg/l). o Suspended solids 30mg/l (increased from the old licence limit of 15mg/l). o Total ammonia 35mg/l. o Molybdate reactive phosphate 2mg/l. An Appropriate Assessment screening and details of assimilative capacity calculations including mass balance calculations and headroom assessment are set out in a number of tables attached to the report. Clare County Council granted a reviewed licence subject to 17 conditions. The copy of the licence decision submitted to An Bord Pleanala is undated. The following conditions are particular pertinent for the purposes of the grounds of appeal. WW03.WW0415 An Bord Pleanála Page 4 of 23 Condition no. 4 Condition no. 4 requires the characteristics of the treated final effluent to discharge to surface water shall not exceed the parameter limits set out in Schedule 1: namely - BOD 20mg/l 02. - COD 100mg/l 02 - Suspended Solids 30mg/l - pH 6-9 - Total ammonia 35mg/l as N and - MRP 2mg/l P. Condition No. 5 The licensee shall undertake a treated effluent monitoring programme on a bi-monthly basis. The programme should be undertaken by a replicable monitoring agency on behalf of the licensee. The parameters to be analysed are listed in Schedule 1 of the licence. The results of the monitoring shall be submitted to the Environment Section of Clare County Council. In the event of any exceedance of the limit value defined in Schedule 1, the licensee shall immediately investigate such exceedance and report the matter as soon as may be to the licencing authority. The submission of results shall then be accompanied by a brief report attributing the causes for the said exceedance and indicating remedial measures taken at the time to ensure (as far as possible) no reoccurrence of the exceedance. Condition No. 7 A monitoring programme shall be commenced on the River Shannon flowing due south of the site, with details of the monitoring locations to be agreed with the licencing authority within one month of the date of grant of this licence. The parameters and frequency of the monitoring associated with this monitoring programme shall be in accordance with Schedule 2 of the licence. Condition No. 10 All pumps and motors shall have appropriate standby facilities which will be controlled (automatically, if deemed to be necessary after the commissioning programme) to operate in an emergency overload situation. These pumps and motors shall be routinely alternated in WW03.WW0415 An Bord Pleanála Page 5 of 23 accordance with good practice. Provision shall be made to use a standby generator in the event of mains power failure. Condition no. 11 In the event of the wastewater treatment plant failure, a holding tank of at least two days capacity shall be provided to hold untreated/partially treated domestic effluent on site. Condition No. 15 The licensee shall appoint a person who shall be responsible for the day-to-day inspection, operation and maintenance of the system.