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tidal influences (clock-times and heights) at Stockton were converted monthly from available f`f' tidal table information on the dates of soundings of the three wells. The Project Status Report `j of Ground-Water Monitoring (W.W. Irwin, Inc., January 30, 1995) contained data which, until the Problem Assessment Report was issued on August 8, 1995, were the most recent regarding site conditions at Village West Marina. 1 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 Plan, Figure 2. Each sample collected from HP-7, HP-8, HP-9, and HP-10 was analyzed for the presence of Total Petroleum Hydrocarbons asgasoline (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. 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 HydropunchTm 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. HP-9 yielded the only sample impacted with elevated concentrations of TPH-g and benzene. Table IA lists the analytical results of the HydropunchT'ground-water samples submitted to Sherwood Labs Corporation of Hilmar, California. ' New monitoring wells MW-7 and MW-8 were developed on July 7, 1995 using sterile, polyethylene bailers. Bailing removed turbid water from the wells until clear water appeared. The monitoring wells were sampled after a minimum of 40 gallons were bailed and the ground- water levels had recovered to at least 90% of their static levels. ;I'_ Following completion of all tasks, the Problem Assessment Report and Project Status Report of Ground-Water Monitoring were issued by W.W. Irwin, Inc. on August 8, 1995. Monitoring activities conducted on October 18, 1995 were documented in the Project Status Report dated October 31, 1995. The Remedial Action Plan with feasibility study were issued on December 28, 1995; W.W. Irwin, Inc. has recommended bioventing with continued ground-water monitoring as the best, cost-effective technologies for cleanup of affected soil and ground water. W.W. Irwin, Inc. 1 Project No. 33016.06 �. April 1996 6