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q � 06 January 2006 AGE-NC Project No 99-0559 Page 2 of 7 Interim ground water remediation by ground water extraction was Initiated at the site on 20 May 2003,in accordance with procedures outlined in the AGE-prepared Interim Remediation and Site Assessment Work Plan, dated 25 January 2001 2.0. GROUND WATER MONITORING AND SAMPLING Ground water monitoring and sampling were performed on 10 November 2005 The work was performed in accordance with guidelines established by the California Regional Water Quality Control Board (CRWQCB) - Central Valley Division for subsurface investigation of underground storage tank (UST) sites, and with the San Joaquin County Environmental Health Department (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 21 WELL MONITORING AND EVACUATION Depth to ground water was measured in wells MW-1 through MW-4 and well chambers A through E of the multi-level wells MW-5 through MW-7 from the top of the well casings to the nearest 0 01-foot,utilizing a Solinist water level meter, ground water elevations and gradients in this report are based on the measured depths After ground water depth measurements, well chambers A through E of the three multi-level monitoring wells were purged by lowering and raising a 3/$-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 0 3 to 5 gallons of ground water(a minimum of three casing-water volumes per well screen) were removed from the momtonng well levels Temperature, pH and conductivity were measured for stabilization at regular purge-volume Intervals during monitoring using an Oakton water analyzer, field data and logs are included in Appendix B Purged ground water was containerized in 55-gallon drums and processed on-site for discharge under permit 2 2 COLLECTION AND ANALYSIS OF GROUND WATER SAMPLES Prior to ground water sampling,the ground water level in each well was measured to ensure that the well achieved a minimum of 80 percent recharge Following depth measurement, ground water samples were collected from well chambers utilizing 3/s-inch diameter polyethylene tubing The ground water samples were transferred into three 40-milliliter(ml) EPA-approved volatile organic analysis (VOA) vials containing 0 5 ml 18% hydrochloric acid as a sample preservative, care was taken to ensure that visible air bubbles were not present in the vials after filling and capping Ground Advanced GeoEnvironmental,Inc