lforrnation Requir C -INF lucture & OPER eraf - Drawing No Drawing No

Transcription

1 C -INF eraf - lucture & OPER lforrnation Requir Outline Description of the Treatment Process at Kiicioon WWTP 8 Agglomeration - Drawing No Co n se nt o f c Fo op r i yr ns ig pe ht ct ow ion ne pu r r rp eq os ui es re o d nl fo y. ra ny ot he ru se. - Drawing No EPA Export :14:29:45

2 OUTLINE DESCRIPTION OF THE TREATMENT PROCESS FOR KILCLOON WASTE WATER TREATMENT PLANT AND AGGLOMERATION 1.0 INTRODUCTION As discussed in Section 6.10 of this application, a new wastewater treatment plant (WWTP) is currently under construction to serve the Kilcloon Agglomeration. The anticipated completion date for this project is September In addition, provision of a new sewerage network to serve the Kilcloon Agglomeration has now reached completion. The following sections describe the processes at the new wastewater treatment plant (for which a Part Viil planning application has been prepared and approved). ) 2.0 EXISTING PLANT Given the relatively small catchment. Kilcloon agglomeration is not serviced by a local authority sewerage system at present. Individual septic tanks currently provide a means of waste water treatment for the agglomeration. 3.0 PROPOSED PLANT (programmed commissioning date - September 2009) The new waste water treatment plant is being constructed on a green-field site located in the townland of Kilgraigue. The new plant will provide effluent treatment to Urban Waste Water treatment standards. The units being provided in the new plant will include: lnlet Pump Sump lnlet works Storm water holding tank Extended aeration treatment unit Tertiary treatment unit Final effluent chamber Sludge recycle pump set Sludge holding tank Control house lnlet Works The inlet works will provide screening of the incoming waste water via 1 nr. automatic spiral screen (6mm stainless steel screen equipped with compaction unit and auto cleaning device), with a bypass manual 25mm bar screen for scheduled downtime of the former. The preliminary treatment will entail the removal of plastics and rags from the waste stream. EPA Export :14:29:45

3 Screened waste water will exit the inlet works and flow towards the inlet pump station. Inlet Pump Sump The inlet pump wet sump consists of a chamber with a 2.0m X 2.0m plan area, containing 2 No. submersible pumps for forward feed of incoming untreated waste water to the process plant. This inlet sump also comprises an ovefflow facility, which will direct storm water to the storm water holding tank. This storm water overflow will cut-in at a level of 3.03m above the sump base. Storm water return will also occur at this pump sump. Storm water holding tank Storm water control is being provided such that 14.7m31hr will flow forward towards the process plant. Flows in excess of 3DWF will be diverted to the storm water holding tank. Storm water will be returned to the inlet pumping station when storm conditions abate, however, during extreme wet weather conditions and in the event that storm water holding tank capacity has been exceeded, there will be a facility for excess storm water to bypass the works. The storm water holding tank has a capacity in the order of 79m3. Secondary Treatment A Compact Aeration Unit (CAU), incorporating a central clarifier unit surrounded by an oxidation ditch will provide biological treatment and settlement to the incoming screened waste water. Waste water will be pumped to the aeration portion (oxidation ditch) of the concentric tank. The CAU has an approximate combined capacity of 222m3 (aeration capacity: 162m3, clarifier capacity: 60m3) with dimensions as follows: Inner Diameter : rn Outer Diameter : 10.6m Liquid Depth of aeration unit : 3.2m Liquid Depth of Clarifier : varies 2.85m to 4.0m A fine bubble diffused air aeration system is being installed in the oxidation ditch base to maintain dissolved oxygen at sufficient levels during the aeration phase. Aerated mixed liquor will flow from the oxidation ditch to the central section of the clarifier via an overflow weir to a GRP diffuser drum. Settled sludge will fall to a base of the clarifiers, while clarified liquid will overtop the clarifier's inner wall, via a stainless steel peripheral weir. The weir will be fitted with a scum draw off device. Final effluent, on exiting the clarifier (via the peripheral weir), will flow forward by gravity to a tertiary microscreen chamber. Settled sludge will be removed from the base of the clarifie~ via a 150mm diameter sludge draw off pipe to a picket fence thickener. EPA Export :14:29:45

4 Nutrient Removal Phosphate removal, in the form of ferric sulphate application will be practiced at the proposed plant. Tertiary Treatment The treatment process will include a microscreen unit as a form of tertiary treatment. This form of treatment will comprise a mechanically operated microscreen, installed to screen final effluent down to 50um. The microscreen will include a self-cleaning device, which will operate on a predetermined headloss. The membrane can be replaced as required for maintenance. Screenings will be returned to the Sludge Holding Tank. Continuous flow monitoring of the treated effluent will occur post microscreening. (A v-notch weir is being installed for the purposes of flow measurement) Proposed Outfall Arrangement The final effluent will exit the works in a 225mm diameter gravity pipeline, which will discharge directly to a stream tributary of the Rye Water. Excess storm water, which may on occasion bypass the works, will combine with the treated effluent downstream of the treatment process in this gravity pipeline and will then co- discharge directly to the stream. Sludge Handling Sludge handling facilities will be provided at Kilcloon in the form of a 3.5m diameter sludge holding tank I picket fence thickener. Thickened sludge will be collected and transported to either Castletown Tara or Navan WWTPs for dewatering. Supernatant drawn from the top of the thickener will be returned to the secondary aeration unit via the sludge recycle pump station. Control Building A new Control Building is being provided at the site to include a toilet, store and control room. Proposed Odour and Noise Control It is a contract requirement that the Kilcloon Waste Water Treatment Plant will comply with the European Communities (Waste Water Treatment) (Prevention of Odours and Noise), Regulations, (S.I. No. 787 of 2005). EPA Export :14:29:45

5 WWTP SlTE BOUNDARY INLET WORKS - SLUDGE RECYCLING PUMP I SLUDGE HOLDING TANK - TANK Cli& MEATH COUNTY COUNCIL Pml'd: KILCLOON WASTE WATER TERTIARY TREATMENT DISCHARGE APPLICATION LICENCE me: PLANT PROCESS SlTE PLAN,(SECTION 1 ATTACHMENT C.1 ) Sds@A3: 1 : 500 Prop.nrlk PWDinMr Chsrial: M.F.G. MAY 09 EPA Export :14:29:45

6 SCREENINGS I OFF-SITE DISPOSAL RAW SCREENING INLET PUMPING MIXED LIQUOR OVERFLOW WASTE ACTIVATEC SLUDGE I TREATMENT I MlPRnSPRFFN >. IER TREATED EFFLUENT REATED EFFLUENT TO PRIMARY ISCHARGE POINT MEATH COUNTY COUNCIL DISPENSER PIDlDd KILCLOON WASTE WATER DISCHARGE LICENCE APPLICATION FERRIC I m c PLANT1 PROCESS FLOW DIAGRAM,(SECTION 1 ATTACHMENT Cl), / STORMWATER ( HOLDING TANH D EXCESS STORMWATER OVERFLOW LINE P,ep.,a(bl; ChSXod: o.,o: R.K M.H. MAY W PmWlli-r M.F.G. TREATMENT WORKS SI EPA Export :14:29:45

7 se Co n f c Fo op r i yr ns ig pe ht ct ow ion ne pu r r rp eq os ui es re o d nl fo y. ra ny nt o se. ru he ot INF STR PEF EPA Export :14:29:46

8 OUTLINE DESCRIPTION OF OUTFALL DESIGN AND CONSTRUCTION 1.0 PRIMARY DISCHARGE POINTS EXISTING PRIMARY DISCHARGE No existing primary discharge points on Kilcloon Sewerage Scheme PROPOSE Location: Receiving Water: Originates: Invert Level: iy DISCHARGE PSWl - Kilgraigue T.D.. Kilcloon, County Meath E, N Discharge to stream tributary of the Rye Water River (Liffey Catchment) Final treated effluent from newly constructed Kilcloon WWTP 67.31m.O.D Pipe Size: 225mm diameter gravity pipeline from WWTP (shared with PSW2 - Design Criteria: Construction Detail: proposed storm water overflow) Continuous flow of treated effluent from WWTP 225mm diameter concrete pipe discharging to headwall EPA Export :14:29:46

9 2.0 SECONDARY DISCHARGE POINTS A site visit was undertaken by TOBlN Consulting Engineers in March I April 2009 during which the study area was examined, however no secondary discharges were identified. There are no secondary discharge points from Kilcloon WWTP and sewerage network, EPA Export :14:29:46

10 3.0 STORM WATER OVERFLOW DISCHARGE POINTS EXISTING STORM WATER OVERFLOW DISCHARGE No existing storm water ovefflow discharge points on Kilcloon Sewerage Scheme PROPOSED STORM WATER OVERFLOW DISCHARGE Location: Receiving Water: Originates: Invert Level: Pipe Size: Design Criteria: Construction Detail: PSW2 - Kilgraigue T.D., Kilcloon, County Meath E, N Discharge to stream tributary of the Rye Water R~ver (Liffey Catchment) Storm water overflows from storm water holding tank at newly constructed Kilcloon WWTP 67.31m.0.D Proposed 225mm d~ameter gravity pipeline from WWTP (shared w~th PSWl -proposed primary d~scharge point) Storm water control will then be provided such that 3DWF will flow forward from the inlet works. Flows in excess of 3DWF w~ll be d~verted to the proposed storm water holding tank. Storm water will be returned to the inlet works when storm conditions abate, however, during extreme wet weather conditions and in the event that storm water holding tank capacity has been filled, there will be a facility for excess storm water to bypass the works. The proposed storm water holding tank will have a capacity in the order of 162m3approximately. 225mm diameter concrete pipe discharging to headwall EPA Export :14:29:46

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12 WWTP SITE BOUNDARY PROPOSED PRIMARY DISCHARGE PROPOSED STORMWATER OVERFLOW MEATH COUNTY COUNCIL we. KILCLOON WASTE WATER DISCHARGE LICENCE APPLICATION rm 'ROPOSED PRIMARY DISCHARGE POINT (PSWI) 8 PROPOSED itormwater OVERFLOW (PSWZ) COlrSTRLCTlON 8 DESlGh ( SECTION I ATTACHMENT C.2 )/ ',cp.ndw Ch.r*d. OdS R.K. M.H. MAY 09 'miodoulra. M F.G. EPA Export :14:29:46