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Interim Ground-Water Monitoring Activities fr i The SJCPHS-EHS then required that ground-water monitoring be undertaken for six months, from August 1994 through January 1995. Samplings of MW-4, MW-5, and MW-6 were performed in September and December of 1994. Soundings were performed monthly. Local tidal influences (clock-times and heights) at Stockton were converted monthly from available tidal table information on the dates of soundings of the three wells. The Project Status Report of Ground-Water Monitoring (W.W. Irwin, Inc., January 30, 1995) contained data which, until l.j the Problem Assessment Report was issued on August 8, 1995, were the most recent regarding site conditions at Village West Marina. Problem Assessment and Completions of MW-7 and MW-8 - On July 3, 1995, W.W. Irwin, Inc. directed the drilling, logging, and sampling of Hydropunches'HP-7, HP-8, HP-9, and HP-10. HP-7 and HP-8 were completed as monitoring wells MW-7 and MW-8 after ground-water samples collected for "rushed" analyses of gasoline .: and diesel analytes at Sherwood Labs in Hilmar were found nondetectable. The new monitoring wells were drilled, sampled, and completed in order to determine the horizontal and vertical extent of soil and ground-water contamination. The new monitoring well locations are initially -. depicted on the Site PIan, Figure 2. Each sample collected from HP-7, HP-8, HP-9, and HP-10 was analyzed for the presence of Total Petroleum Hydrocarbons as gasoline (TPH-g) by modified EPA Method 801515030, Total Recoverable Petroleum Hydrocarbons as diesel (TRPH-d), and the volatile aromatics benzene, toluene, ethylbenzene, and total xylenes (BTEX) by EPA Method 8020. All soil analytical results are listed in Table 1. The laboratory reports and accompanying chain.-of-custody are included as Appendix D. Detectable, primarily fractional BTEX analytes were detected only in soil samples collected from HP-7 at 15 feet, and from HP-9 at 15 feet. The highest TPH-g result was 3 mg/Kg, revealed in the sample collected from HP-9. TRPH-d results were wholly nondetectable. 1 HydropunchTa' ground-water samples were collected from HP-7 at 19 feet; from HP-8 at 21.5 feet; from HP-9 at 23.5 feet; and from HP-10 at 21.5 feet bsg. Boring logs of HP-7, HP-8, HP- 9, and HP-10 are included within Appendix B. HP-9 yielded the only sample impacted with elevated concentrations of TPH-g and benzene. Table IA lists the analytical results of the Hydropunch' ground-water samples submitted to Sherwood Labs Corporation of Hilmar, California. w.w.lmiL Inc. Project No.33016.06 octolm 1993 6 I