ATTACHMENT C.1

OPERATIONAL INFORMATION REQUIREMENTS

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EPA Export 26-07-2013:14:50:04

Ballinagar Agglomeration WWD Application Form Version 6/08 Offaly County Council RPS Consulting Engineers

MDW0261RP0003 50 F01

Attachment C.1: Operational Information Requirements

Introduction Ballinagar is a small village located in County Offaly. It is approximately 12km from Tullamore and 85km from Dublin. The Ballinagar Plant is located approximately 400m south from the main road in Ballinagar. Ballinagar Sewer Collection System Ballinagar Sewer Collection system is a combined system constructed in the mid 1980’s. Sewerage from the Ballinagar Agglomeration flows by gravity to the Wastewater Treatment Plant located approximately 400m south of the Town. Collection System consists approximately 1900m of 225mm diameter PVC pipe and 27 manholes. There are no Pumping Stations or Combined Sewer Overflows in the Ballinagar Collection System. Ballinagar Sewer Collection System is shown on MDW0261B – C.1 Waste Water Treatment Plant – Current Situation The current form of treatment at the Ballinagar WWTW is compact activated sludge system complete with an internal clarifier. The treatment works was constructed in the mid 1980’s and is believed to have been originally designed to treat a 200 population equivalent (PE).

Photograph no.7 Ballinagar Waste Water Treatment Plant – Existing CAS Tank The 2006 Feasibility Report recommended that a compacted activated sludge (CAS) tank capable of treating up to 800 PE be installed at Ballinagar. The existing works could them be assessed and retrofitted to provide a possible additional capacity of 200 PE. It was

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EPA Export 26-07-2013:14:50:04

Ballinagar Agglomeration WWD Application Form Version 6/08 Offaly County Council RPS Consulting Engineers

MDW0261RP0003 51 F01

also recommended that a picket fence thickener, adequately sized to treat the sludge generated by 1000 PE, be installed to provide necessary on-site sludge storage. The recommendations from the 2006 Feasibility Report were revised in 2008 and new structures were added, such as Inlet Works consists of an Automatic Inlet Screen and a Storm Overflow Chamber. A Storm Water Holding tank and Ferric Dosing System have also been proposed. Wastewater Treatment Plant – Upgrade Proposal The basic design data of the upgraded WWTW is outlined below:

Population Equivalent 1000 PE

Dry Weather Flow (1 DWF) 225 m3/day = 2.6 l/s

Max. Flow into IW (8 DWF) 1800 m3/day = 20.8 l/s

Maximum Flow through WWTW (3DWF)

675 m3/day = 7.8 l/s

Max. Flow to Storm Tank (5 DWF) 1125 m3/day = 13 l/s

Proposed upgrade works for Ballinagar WWTW will consist of:

• New Inlet Works Chamber,

• Split Flow Manhole,

• Ferric Sulphate Dosing System,

• New CAS tank,

• Picket Fence Thickener,

• Storm Water Holding Tank,

• Final Effluent Chamber. Process description

The proposed Inlet Works for Ballinagar will consist of Inlet Screen System and Storm Overflow System. It will have a total capability of screening 8 x DWF (20.88 l/s). The proposed inlet screen system will contain an automatic 6mm mechanical screen capable of screening 6 DWF (15.66 l/s). If flow exceeds 6 DWF the overflow is screened through a manual 20mm screen. If the automatic screen is out of service the manual 20mm screen takes all the influent. The automatic screen removes the screening to bin(s). The screening bin will be provided with a shroud or cover to prevent the ingress of rainwater into the bin. The screening bin standing area will be drain back into the inlet works. Downstream of the Inlet Screen System the open flow channel will carry up to 3 DWF (7.83l/s) into the Treatment Works, with any excess screened influent being diverted to the storm water holding tank.

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EPA Export 26-07-2013:14:50:04

Ballinagar Agglomeration WWD Application Form Version 6/08 Offaly County Council RPS Consulting Engineers

MDW0261RP0003 52 F01

Storm water from Storm Water Holding Tank will be pumped back to Inlet Works when flow upstream of the Inlet Works drops below 1.5 DWF (3.9 l/s). If storm flows continue, the storm water will overflow to the final effluent outfall. An Auto-sampler will be located downstream of the proposed Inlet Works. From the inlet works, the screened wastewater gravitates into the Split Flow Manhole which will allow operation of either the new CAS tank, the existing Oxidation Ditch or both. Ferric Sulphate will be dosed into Split Flow Manhole for P- removal. Flow will enter the CAS tank via 225mm dia. inlet which will be controlled by means of a manual adjustable penstock. The CAS system is designed to handle loads up to 800 PE and consists of two concentric tanks, the outer circuit being the aeration tank. Sludge will settle in the central hopper (with a 60o slope) of the clarifier and from there it will be returned or wasted by means of a submersible RAS/WAS pump. Sludge can be wasted directly from the sludge hopper to the PFT via the DI drain-off pipe. Final effluent emanating from the clarifier will flow by gravity to the outlet pipe via a proposed Final Effluent Chamber. At the inlet to the clarification zone there will be a manually adjustable penstock to control flow to the tank. A 4.3 diameter Picket Fence Thickener will be installed. The tank will be complete with tank roof, passive odour treatment and full tank fittings to provide storage for sludge at 3% TDS. The volume of surplus sludge to be wasted from the CAS process is expected to be approximately 11.2 m3/day at up to 1%DS and this will be pumped through a 150mm diameter rising main to the picket fence thickener. The PFT tank will provide on-site storage for up to 7 days. Supernatant from the PFT will overflow by gravity to the Supernatant manhole and then to the CAS tank for return to the process. Thickened sludge will be removed via 150mm diameter DI tanker connection. Final effluent from proposed CAS Tank will gravitate to the Final Effluent Manhole where an Auto-sampler will be located. Downstream of the Final Effluent Chamber, a flow meter will measure the volume of treated wastewater discharged. A Site Layout showing all proposed and existing structures at Ballinagar WWTW is included as MDW0261B – C.1.1. A Proposed Flow diagram is presented on MDW0261B – C.1.2 Discharge Specification As the river is not designated as being Salmonid or a shellfish water, and it is not designated as being used for bathing or for the abstraction of surface water for the use as drinking water, phosphorus is the limiting pollutant from the Wastewater Treatment Works. As the Tullamore River has no capacity to assimilate this parameter the BATNEEC approach will be employed. This will ensure that whilst the permissible downstream concentration of 0.05mgP/L will not be achieved, the best possible standard will be attained, without entailing excessive costs. The discharge standards, set out in Table C.1, are recommended for the Ballinagar Wastewater Treatment Works.

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EPA Export 26-07-2013:14:50:04

Ballinagar Agglomeration WWD Application Form Version 6/08 Offaly County Council RPS Consulting Engineers

MDW0261RP0003 53 F01

Table C.1 – Discharge Standards

Parameter UWWT

Regulations mg/L

Compliance

Recommended Discharge Standards

mg/L

Biochemical Oxygen Demand

25 95%ile 25

Suspended Solids 35 95%ile 35

Chemical Oxygen Demand 125 95%ile 125

Ammonia (NH3) as N - Summer

Not stipulated N/a N/a

Ammonia (NH3) as N - Winter

Not stipulated N/a N/a

Total Nitrogen N/a N/a N/a

Total Phosphorus N/a Median 2*

Ortho-phosphate (PO4) as P N/a Median 1*

* BATNEEC Standard

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ATTACHMENT C.2

OUTFALL DESIGN AND CONSTRUCTION

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Ballinagar Agglomeration WWD Application Form Version 6/08 Offaly County Council RPS Consulting Engineers

MDW0261RP0003 55 F01

ATTACHMENT C.2: Outfall Design and Construction As described in Attachment A.1 the final effluent from the treatment plant is discharged to a 200mm diameter pipe which outfalls to the Ballinagar Stream which is a tributary of the Tullamore River at the primary discharge point.

Photograph no. 8 Ballinagar Waste Water Treatment Plant – Outfall. There are no construction details of the Outfall from the Plant.

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