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' • Remediation Well Installation Work Plan New West Flag City Facility ' August 7 2008 6437 W.Banner Street, Lodi, California ' The area surrounding the Site is zoned for commercial use. Commercially developed properties surrounding the Site include fueling stations and convenience stores, restaurants, hotels, and a ' fire station. An active Chevron branded gasoline service station and an active Unocal branded gasoline service station operate south and southwest, respectively, of the Site. ' The Site is generally flat at an elevation of approximately 10 feet above mean sea level (msl). The Site is mostly asphalt paved with planted areas along the sides of the property and adjacent ' to the building. The Site drainage flows into storm drains which eventually discharge into White Slough approximately one mile west-southwest of the Site. 1.2 PREVIOUS ENVIRONMENTAL ACTIVITIES ' An active Chevron branded gasoline service station and an active Unocal branded gasoline service station operate south and southwest, respectively, of the Site. In February 2005, the Chevron station reported the presence of methyl tertiary butyl ether(MTBE) in monitoring wells down-gradient of the New West facility. As a result of this report, the San Joaquin Environmental Health Department (SJEHD) directed New West to investigate potential impacts ' to soil and groundwater in the vicinity of the New West facility. t In August 2005, APEX Envirotech, Inc. (APEX) installed six groundwater monitoring wells (MW-1, MW-2, MW-3A, MW-313, MW-4A and MW-413). Elevated concentrations of MTBE were detected in soil and groundwater, indicating that a release had occurred from the facility. Due to the proximity of the facility to two municipal wells (CSA-31-1 and CSA-31-2), periodic sampling of the municipal wells was implemented in October 2005. The samples collected from ' the municipal wells have not reported concentrations of MTBE above the laboratory detection limits, indicating that the MTBE plume has not impacted the wells. In November 2005, in an effort to further delineate the lateral and vertical extent of the MTBE plume, monitoring wells MW-5A, MW-513, MW-613 and MW-6C were installed by APEX. ' Five groundwater extraction wells (EW-I through EW-5) were installed along the southern ' property border from October to November 2005. In April 2006, groundwater batch extraction was initiated at the Site, ultimately removing 103,150 gallons of water over the course of approximately five months. The batch extraction events were thought to have removed ' approximately 38.73 pounds of MTBE. A fixed base groundwater extraction and treatment system consisting of five pneumatic extraction pumps, an air stripper, two 1,000-1b Vapor Phase 1 ' Page 2 of 9