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25 January 2005 <br /> AGE-NC Project No 99-0559 <br /> Page 4of12 <br /> INSTALLATION OF GROUND WATER RECOVERY WELLS <br /> On 01 and 02 April 2003,four ground water extraction well EW-1 through EW-4 were installed on <br /> the site The wells were single-completed as ground water extraction wells with a 4-inch diameter <br /> perforated well casing to a depth of 80 feet bsg <br /> INSTALLATION OF GROUND WATER EXTRACTION SYSTEM <br /> The ground water extraction system consisting of the ground water treatment unit and associated <br /> piping was installed between 18 February and 26 June 2003 <br /> GROUND WATER TREATMENT OPERATION <br /> The ground water treatment system is designed to operate at a maximum flow rate of up to <br /> 10 gallons per minute (GPM), each of the four recovery wells extracts ground water at a flow rate <br /> . of approximately 2 to 2 5 GPM,by extracting on an intermitting cycle The operation of the pumps <br /> allowed for a hiatus when water fall below the pump inlet to allow the well to recharge,after which <br /> the pump will reactivate The ground water treatment system operates on a batch basis,with a daily <br /> total of up to 4,000 gallons Once the sediment holding tank fills, approximately 250 gallons of <br /> extracted ground water is treated and discharged The discharge oftreated water(effluent)to the City <br /> of Stockton was adjusted at a flow rate of approximately 10 GPM <br /> ON-SITE CPT LITHOLOGIC INVESTIGATION APRIL 2001 <br /> Three soil borings(CPT-1, CPT-2 and CPT-3)were advanced on-site utilizing CPT technology to <br /> model the geological and hydrogeological framework and to assess the vertical extent of dissolved <br /> petroleum-hydrocarbons beneath the site Lithologtc data was collected from an initial CPT soil <br /> boring in each locality,a twin boring was then advanced immediately adjacent to the initial CPT soil <br /> boring to collect soil and grab ground water samples from selected depths Soil borings CPT-1, <br /> CPT-2 and CPT-3 were advanced vertically to maximum depths of approximately 155 feet below <br /> surface grade(bsg), 162 feet bsg and 158 feet bsg,respectively CPTI was advanced at the western <br /> edge of the site,in the down-gradient direction from the UST area,CPT2 was advanced adjacent to <br /> the UST release, within the core area of the hydrocarbon-impacted vadose soil, and CPT3 was <br /> advanced along the southern edge of the site,at the furthest southern point on the site from the UST <br /> release, in a cross-gradient location A site plan depicting boring locations is presented in Figure 2 <br /> I <br /> Advanced GeoEnvironmental,Inc <br />