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d� ,< L) 30 October 2004 AGE-NC Project No 96-0232 Page 2 of 14 2 0 GROUND WATER PUMP AND TREAT REMEDIATION SYSTEM Between 15 June and 17 August 2004 (third quarter 2004), a ground water pump-and-treat remediation system was in continuous operation at the site Ground water pump-and-treat operation 4 and maintenance procedures for the site were outlined in AGE's Final Remediation Plan, dated 31 August 2000 In accordance with an RWQCB-approval letter(dated 13 August 2004)to cease ground water pump- and-treat operations due to the lack of cost effectiveness,Flag City Chevron ground water pump-and- treat operations were suspended on 17 August 2004 2 1 GROUND WATER PUMP AND TREAT OPERATION The Flag City Chevron ground water pump-and-treat system was designed to operate at a maximum flow rate of 25 gallons per minute(GPM) Between 15 June and 17 August 2004, on-site extraction wells EW-4, EW-5, EW-7, EW-8 and EW-10 were adjusted at each well-head to continuously extract ground water at a flow rate of approximately 4 to 5 GPM During the third quarter, all extracted ground water was routed through a ground water treatment system consisting of coconut shell, liquid phase granular activated carbon (GAC) Following treatment,water was discharged to a conveyance ditch(located approximately 450 feet south of the site) at a flow rate of approximately 20 to 25 GPM Field notes of ground water pump and treat operation and maintenance activities are in Appendix A Based on effluent flow meter readings (Appendix A, Table 5) during the third quarter 2004, approximately 885,468 gallons of Flag City Chevron treated ground water were discharged to the above referenced conveyance ditch under RWQCB General Order 5-00-119 for discharge to surface waters of groundwater from cleanup of petroleum fuel pollution Since initiation of the groundwater pump-and-treat remediation system on 20 November 2000, a grand total volume of approximately 27, 086,201 gallons of MTBE-impacted water has been treated and discharged to the conveyance ditch under RWQCB waste water discharge permit no CAG915001 [National Pollutant Discharge Elimination System (NPDES)] 2 2 GROUND WATER PUMP AND TREAT SAMPLING PROCEDURES In accordance with RWQCB Monitoring and Reporting Program No 5-00-119,monthly sampling of influent and effluent waters from the pump-and-treat system and receiving water was required for . analysis for petroleum constituents of concern Advanced GeoEnvironmental,Inc