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L AMB IA INTERIM REMEDIAL ACTIVITIES Cambria performed interim remedial activities at the site during March 2004, which consisted of groundwater extraction from two onsite groundwater monitoring wells The primary objective of interim groundwater extraction was to remove 1,2-DCA mass from the groundwater and the secondary objective was to assess the aquifer's hydraulic properties Personnel Present. Cambria field technician Dayton Busch conducted the field activities, working under Senior Project Engineer Dan Lescure's supervision Well S-1-85 Step Discharge Test On March 30 and 31, 2004, Cambria conducted a step discharge test on well S-1-85 Groundwater was extracted using a 2-inch diameter Grundfos electric submersible pump The extracted groundwater was temporarily stored in an on-site storage tank, and later transported via vacuum truck to the Shell refinery in Martinez, California for recycling The following parameters were monitored during each step duration, flow rate, extracted • groundwater volume, and drawdown A totalizing flow meter was used to monitor the flow rate and number of gallons pumped during the tests Pressure head measurements were collected from well S-1-85, S-3-84, and S4-83 using MmiTrollTM pressure transducers Water levels were also checked manually with an electronic water level indicator from these and other wells Samples were collected periodically from the extracted groundwater stream during the test and retained in vials containing hydrochloric acid preservative with no head space These samples were labeled, entered onto a chain-of-custody record, and placed into a cooler with ice for transport to a state of California certified laboratory for analyses The samples were analyzed for TPHg,BTEX,MTBE,and 1,2-DCA by EPA Method 8260B S-1-85 Step Discharge Test Results On March 30, 2004 the first step was performed at an extraction rate of approximately 0 5 gallons per minute (gpm) Initially, the pump was set approximately 1 foot above the bottom of the well However, sands and silts within the well inhibited pump operation The pump was reset (raised) to approximately 73 5 fbg to alleviate this problem The initial pumping rate (0 5 gpm) was maintained for 99 minutes until the water table stabilized at 0 460 feet of drawdown A second step was performed at an extraction rate of approximately 10 gpm This pumping rate was maintained for 96 minutes until the water table stabilized at 0 976 feet of drawdown A third step was performed at an extraction rate of approximately 2 0 gpm This pumping rate was maintained for 62 minutes until the water table 0797 6