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' 11 January 2006 AGE-NC Project No 95-0130 IPage 8 of 14 ' for the site were outlined in AGE's Interim Remediation Work Plan-May 2003,dated 21 May 2003 ' 41 GROUND WATER EXTRACTION-TREATMENT OPERATION During the third quarter 2005,extraction wells EW-1 and EW-2 were each adjusted at the well-heads ' to continuously extract ground water at a combined flow rate of approximately 1-2 GPM,however, due to ground water draw-down issues at EW-1 and EW-2, electric timers were installed to cycle EW-1 and EW-2 on and off at alternating 1-hour intervals All extracted ground water from EW-1 ' and EW-2 was routed from the extraction wells to a 5,000-gallon holding tank, from the holding tank, water was treated by passing through a low profile air stripper,then through four 2,000 pound media vessels containing liquid phase granular activated carbon(GAC) Following treatment,water was discharged underground via 1-inch diameter PVC piping to the City of Stockton sewer system, discharge piping is connected to a sewer clean-out located in a east section of the site,approximately 100 feet east-northeast of the pump-and-treat system ' On 17 August 2005, 13/4-inch diameter,stainless steel,submersible-fluid pneumatic extraction pumps (QED model AP-2) were installed in wells V W-1 C, VW-2A and VW-3A in accordance with a ' . SJCEHD directive letter, dated 29 June 2005 From VW-1C, VW-2A and VW-3A, independent, '/z-inch diameter polyethylene water discharge lines were routed underground from each pneumatic pump to the 5,000-gallon holding tank, '/2-inch diameter polyethylene compressed air lines were ' routed underground from each pneumatic pump to a 5-horsepower, Speedaire (model no 5F229B) electric air compressor located inside the remediation fenced area Additionally, independent, ' 13/4-inch diameter PVC piping was utilized for secondary containment from wells VW-1C,VW-2A and VW-3A to the pump-and-treat remediation fenced area Continuous ground water extraction activities were initiated on 17 August 2005 at wells VW-1C, VW-2A and VW-3A to augment the ' on-going P&T remediation system, ground water extraction rates were adjusted at each well to extract ground water at an approximate rate of 3/4 gallons per minute ' Based on effluent flow meter readings (Table 9), approximately 255,480 gallons of treated water were extracted, treated and then discharged to the City of Stockton sewer system between 03 June 2005 and 07 September 2005 under City of Stockton Department of Utilities Ground Water ' Discharge Permit (dated 11 August 2003) I42 GROUND WATER EXTRACTION-TREATMENT SAMPLING PROCEDURES Ground water extraction and treatment influent,intermediate(AFT-AS)and effluent water samples ' were collected on a monthly basis from valved ports located upstream(influent),after the air stripper • (intermediate, AFT-AS) and downstream (effluent) of the treatment unit The grab water samples IAdvanced GeoEnvironmental,Inc I