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INTRODUCTION This update, STATUS UPDATE 44, presents data from March 19, through June 27, 1996 and includes the Quarterly Ground Water Sampling, Vapor Extraction System Monitoring and Venting of MW8 The permit to dump treated ground water to the sewer has been renewed Presently we are batch dumping the treated water from the "ConVault" whenever it is full The water for treatment is collected from the vapor recovery condensate dropouts and produced from the sampling and monitoring of the monitor wells by Lawrence Tank Testing (LTT) pumping service LOCATION The station is located at 6425 Pacific Avenue at the intersection of Douglas Road, Stockton, in San Joaquin County, California . The site lies in Section 21; T2N, R6E, MDB&M at approximately 12 feet above mean sea level (MSL) (see Figures 1, 2, 3) . The parcel is # 31 and can be located in Assessor' s Book 97 on page 41 (97-041-31) . On October 2, 1992, a licensed surveyor with Nolte & Assoc surveyed all monitoring well locations and top of casing elevations to a known datum, ie . City of Stockton Bench Mark Number 12, elevation 11 74' above mean sea level . GROUND WATER MONITORING Depth to ground water measurements and water samples were obtained from all monitor wells on April 9, May 28 , and June 20, 1996 . The vapor extraction system (VES) was operating at those times Corrections for vacuum were necessary for the depth to water measurements, see Appendix D - Field Notes and Methods and Proceedures . Figure 4, represents the measurements obtained on June 20, 1996 . Ground water gradient shows a continuation of a recharge cycle, with ground water rising approximately two feet across the site A low pressure basin is forming at the wells being used for vapor recovery (MW2, MW3 and MW10) The overall flow direction is predominately to the east . GROUND WATER SAMPLING On June 20, 1996, quarterly ground water samples were obtained from all of the wells, see Table 1 and Appendix A. These samples were collected by a WEGE Geologist and "Chain of Custody" delivered on ice to State certified testing laboratory, AMERICAN ENVIRONMENTAL NETWORK, INC. DHS #1172 , for chemical analyses These samples were analyzed for TPH, BTEX and MTBE concentrations using EPA Methods 8015/5030 and 602 respectively During this sampling total Dissolved Oxygen was also measured, see Appendix A, Table 1 and Figure 5 The next quarterly sampling will occur in September, 1996 . PAGE 1 R603 UPDATE-44 7/19/96