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• 10 April 2003 ' AGE-NC Project No 99-0559 Page 2 of 8 LRegional Water Quality Control Board (CRWQCB) - Central Valley Division for subsurface investigation of underground storage tank(UST)sites,and with the EHD-approved Preliminary Site Assessment Work Plan, dated 12 October 1999,and Interim Remediation and Site Assessment Work ' Plan, date 25 January 2001, both prepared by AGE ' 2 1 WELL MONITORING AND EVACUATION ' On 14 January 2003, depth to ground water was measured in wells MW-1 through MW-8E, except well MW-6D, from the tops of the well casings to the nearest 0 01-foot utilizing a Slope water level meter, ground water elevations and gradients in this report are based on the January 2003 depth measurements On 14 and 15 January 2003, dedicated, disposable polyethylene bailers were utilized to purge standing water from wells MW-1 through MW-4 Except for well MW-2, which was purged dry after 2 gallons of ground water and free product was removed, approximately 3 gallons of water(a minimum of three casing water-volumes per well)were removed from the wells Approximately 1 5 feet of free product were removed from well MW-2, during the monitoring event The well chambers of the multi-level monitoring wells MW-5 through MW-8 were purged by Iowering and raising a 3/8-inch outer diameter, length-discrete polyethylene hose equipped with a ball-valve water tip through the top chambers into the specific water-charged screened section Approximately 1 to 4 gallons of ground water, when available (a minimum of three casing-water volumes per well) were removed from the multi-level monitoring well levels A, B, C, D and E Temperature,pH and conductivity were measured for stabilization at regular purge-volume intervals using an Oakton water analyzer Field data and logs are included with Appendix A Purged ground water was containerized in 55-gallon drums and was stored on-site in an area lacking general public access 2 2 COLLECTION AND ANALYSIS OF GROUND WATER SAMPLES Prior to ground water sampling, the ground water level of wells MW-1,MW-3,MW-4,multi-level monitoring well levels B, C, D and E were measured to insure that the wells achieved a mimmum of 80 percent recharge prior to sample collection Following measurement, ground water samples were collected from purged wells MW-1, MW-3 and MW-4 utilizing disposable polyethylene l bailers, and from wells MW-5A through MW-8E utilizing 3/8-inch diameter polyethylene tubing l The ground water samples were transferred into three 40-m1 EPA-approved VOA vials containing 0 5 ml 18% hydrochloric acid as a sample preservative, care was taken to ensure that visible air I Advanced GeoEnvsronmental,Inc