Rye Valley Foods August 2006 IPPC Application Attachment E.3.

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1 ATTACHMENT E.3 EMISSIONS TO SEWER E.3.1 Description of Emissions to Sewer Rye Valley Foods has one emission point to the sewer (SE-1 Effluent Treatment Plant final effluent). See E Site drainage map for foul and process line. All foul and wash water from the on-site toilets and canteen enter the sewer system through a series of drainage pipes. All process wastewater is collected in the designated process water drainage system and conveyed to the effluent plant crude sump prior to pumping to the effluent treatment plant balancing tank. See E Site drainage map for foul and process line. Process effluents arise from the following areas: Cooking and cooling of rice CIP system (Clean In Place) Boilers General washing within the processing areas All effluent is discharged to the sewer under the conditions of Local Authority Discharge License Reference 1/02. Potable water is used during the cooling process and again this is transferred to the effluent treatment plant through the designated pipe work within the factory. This cooling water contains no contaminated material. Boiler and condenser condensate and blowdown are also transferred to the final effluent plant sump and pumped to sewer with the treated effluent, emission point SE-1. List of Emission Points Emission Point Reference No. Description Grid Reference SE 1 Treated Effluent Final Discharge to sewer

2 E Different drainage systems on site There are four defined plant drainage systems as follows: System Process Drainage Line Foul Drainage Line Condensate Drainage Line Surface Water Drainage Line Source All internal plant processing areas Canteen, toilets and other auxiliary areas Boiler condensate All external yard and roofed areas E.3.2 Treatment of Emissions The primary treatment plant consists of the following 9 stages: Crude Effluent Sump All process effluent firstly enters this sump, which contains a course screen basket, which removes large items before entering the sump. Balance Tank The balance tank is equipped with a rotary screen which removes smaller food solids to a designated rendering skip and also a fixed submersible aerator for tank aeration and mixing. The effluent level is maintained by an ultrasonic level monitor. The aim of the balance tank is to equalize the flow from the factory and also to store the effluent. Flash mixing tank The effluent is pumped from the balance tank to the flash tank in which a coagulant (Ferric Sulphate) and flocculent (polymer) are added to aid solid separation in the two SCAF units. Caustic soda 30% is also added for ph correction. SCAF Units The effluent flow is then split between two SCAF units into which submersed air is pumped. The design of this unit is based on retention time and on solids to surface rate. As the solids rise to the surface, it is continuously scrapped off into a sludge holding chambers in the SCAF units. Final Effluent Sump The treated effluent from the two SCAF units enter this sump by gravity flow. Effluent is pumped from here to the sewer at emission point SE-1.

3 Sludge Holding Tank This tank holds sludge from the two SCAF sludge holding chambers. It is mixed on time basis before been pumped to centrifuge. Sludge De-watering The sludge is de-watered by means of a centrifuge. In order to improve the dewaterability, polymer is added. Filtrate and wash water is returned to the crude sump. The dewatered sludge (solids content 20%) is collected in a sludge tanker for off-site land injection. Below are environmental procedures for the operation and running od the effluent plant. EP Number Procedures Operation of Centrifuge Cleaning of DAF Unit Cleaning of Crude Sump Basket Emptying and Cleaning of SCAF Emptying and Cleaning of the Final Effluent Sump Operation of Effluent Plant Automatic Sampler Emptying and Cleaning of Crude Sump Lime Addition to Sludge Holding Tank Procedure Emptying and Cleaning of Balancing Tank Handling of Chemicals in Effluent Plant Restarting Effluent Plant in the Event of a Power-Cut or Emergency Stop Button Activation

4 Figure E.3.2 Effluent Treatment Plant Process Flow PROCESS WASTE FROM FACTORY CRUDE SUMP COARSE SCREEN SOLIDS TO LANDFILL SOLIDS AERATION/MIXING BALANCING TANK SMALL FOOD SOLID S REMOVED TO RENDERING SKIP SCAF TANK NO 1 FLASH TANK ADDITION OF FERRIC SULPHATE, POLYMER AND CAUSTIC SODA. SCAF TANK NO 2 ADDITION OF LIME SLUDGE HOLDING TANK FINAL EFFLUENT SUMP ADDITION OF POLYELECT ROLYTE CENTRIFUGE MAIN SEWER LINE SE-1 SLUDGE TANKER FOR LAND INJECTION

5 E.3.3 Monitoring of Emissions Final effluent discharges from the plant to the Carrickmacross town sewer are monitored in accordance with the requirements of the Local Authority Discharge License 1/02. The following are analysed on a weekly basis by an external laboratory COD, BOD and FOG s. COD, ph and temp are internally analysed and recorded daily. Flow is recorded on a 24-hour basis. Effluent plant monitoring procedures are as follows EP EP4.5.3 EP4.5.8 EP EP EP EP Final effluent sample s for analysis. Effluent plant check- list Test for COD Calibration of SCAF tank ph probe Final effluent monitoring External calibration of effluent plant flow meters External calibration of the Hach meter E.3.4 BAT Evaluation For the purposes of BAT evaluation, the principal stages of wastewater treatment plant operation were evaluated against the EPA draft note on Sector (BATNEEC). Element Abatement / Treatment Method Referenced in BAT Primary Treatment Separation Dissolved air flotation Yes (DAF) Sludge Treatment Centrifugation Yes Sludge Management Landspreading (in accordance with NMP) Yes

6 STAFF ENTRANCE Rye Valley Foods August 2006 E.3.5 Process and Foul Drainage Map, showing sewage emission point SE1 way out way in