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+ * # N.04 08 November 2000 AGE-NC Project No. 95-0142 Page 9 of 9 4.4. WELL DEVELOPMENT Development of the proposed wells will consist of a combination of bailing with a stainless steel bailer to remove the major portion of fine-grained sediment from inside the well, surging to flush out or draw in sediment from the filter pack and additional ground water evacuation (purging) with a submersible pump to finish the removal of fine-grained sediment.Developmental purging activities will be continued until field parameter(pH, electrical conductivity, and temperature) readings have stabilized and purged water is visually sediment-free. 4.5. GROUND WATER EXTRACTION TEST A drawdown pilot test will be performed to evaluate feasibility of ground water drawdown in conjunction with SVE and to remove hydrocarbon mass through ground water extraction. A downhole water pump will be utilized to induce a decline in static water level in the extraction well; pressure transducers will be deployed in surrounding wells to measure difference in ground water levels before well pumping and at set time intervals during well pumping. Ground water will be extracted from the extraction well (EW-1), ground water level observations will be collected from soil vapor extraction wells VW-1, VW-2, ground water monitoring well MW-6, and extraction well EW-2. The ground water will be extracted utilizing a submersible,4-inch diameter Grundfos Rediflow self- priming downhole pump. The ground water pumping rate will be increased at regular intervals to achieve the optimum pumping rate for the greatest drawdown influence. During the pumping, the estimated ground water extraction flow rate will vary between five and ten gallon per minute. If the decline of the ground water level is not satisfactory within the first eight hours of the pilot test, an additional eight hours of ground water extraction will be performed to allow for sufficient ground water drawdown. Purged ground water will be containerized in a 9,000-gallon Baker tank; four composite "grab" ground water samples will be collected from the inlet to the Baker tank for analysis of TPH-g, BTEX and MTBE in accordance with methods listed in Section 3.4. The purged ground water will be discharged into the City of Stockton sewer system pending regulatory approval or be transported to a suitable hazardous waste facility. The duration of the initial drawdown pilot test will be a minimum of 8 hours. The proposed drawdown pilot test will be designed to obtain general aquifer characteristics such as hydraulic conductivity,transmissivity, well effectiveness (efficiency) and drawdown at various pumping rates. The 24-hour drawdown test will be conducted at a constant rate determined by the optimum pumping rate determined from the 8-hour test and the available storage space for produced ground water. Advanced GcoEnvironmental,Inc.