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rr Interim Remediation Work Plan 419 S.Main Street,Manteca,CA June 25,2003 Page 6 The purge water discharged from the well during development will be placed in 55-gallon drums, sealed, labeled, and left on-site pending results of laboratory analyses. Groundwater samples will be collected from the monitor well for laboratory analysis during the first monthly groundwater monitoring event following installation of the monitor well. 5.0 EXTRACTION WELL PUMP TEST Condor will conduct a 72-hour pump test of the extraction well, EW-1. The results of the pump test will be used to size system components for containment of the contaminant plume, and treatment and discharge of the groundwater. During the pump test, observations of the head pressure response in three site monitor wells will be electronically recorded with transducers for later analysis. It is anticipated that transducers will be placed in MW-1, MW-2, and MW-7. Test pump discharge lines will be equipped with cumulative flow meters to record extraction volumes and to calculate pumping rates. The pump test is proposed to be conducted at a constant rate with the option of increasing or decreasing the extraction rate at the discretion of the supervising geologist depending on well response. The goal will be to determine the pumping rate required to extend the radius of influence to MW-2. The test will last three days or less and may be terminated by the geologist if the objectives of the tests are met. Groundwater pumped from the extraction well will be treated by passing the water through coconut shell low granulated activated carbon canisters. The treated water will be stored in temporary storage tanks on the site pending laboratory analytical results showing the treated water meets the requirements of the City of Manteca for discharge to the sanitary sewer system. Upon approval by the City of Manteca, the treated water will be discharged to the sanitary sewer system. Condor will prepare an Industrial Wastewater Discharge Permit (IWDP) application and will receive the permit from the City of Manteca Department of Public Works prior to discharging water to the sanitary sewer. An area at the northwest corner of the parking lot will be fenced to provide a secure area for the carbon canisters. The canisters will be connected y to the sanitary sewer system on the site property for the duration of the pump test. Condor anticipates that four water samples will be collected during the pump test. One sample will be ` collected from the extraction well discharge at the beginning of the test and one sample will be collected from the extraction well discharge at the end of the test. In addition, at least two samples will be collected following on site treatment to assist with meeting the IWDP permit disposal requirements. 6.0 LABORATORY ANALYSES The groundwater samples collected during the pump test will be analyzed for BTEX and selected gasoline oxygenates/additives by EPA Method 8260B, and TPH-G by Method 801513. The selected oxygenates/additives included MTBE, ethanol(EtOH), TBA, di-isopropyl ether(DIPE), ethyl tertiary-butyl ether (ETBE), TAME, 1,2-dichloroethane (1,2-DCA), and 1,2-dibromoethane (EDB). The analytical methods and analytical detection limits are presented in Table 1, on the next page. V 60 i� CONDOR r