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w 4.2 Ground-Water Sampling Prior to normal well-sampling procedures on June 20, 1994, ground-water sampling equipment was steam-cleaned and/or washed in Liquinox@ prior to sampling and between sampling each well. Water condition parameters of temperature, conductivity, and pH were measured and logged during well-purging prior to sampling the wells. Purging was continued until at least three well-volumes of water were removed from each well, and water condition parameters had stabilized. The Well Sample Monitoring Logs and surveyor's sheet are included as Appendix C. Each ground-water sample was collected within a clean, disposable, polyethylene bailer >j lowered to just below the water surface. Each ground-water sample was brought to the surface and immediately transferred to two-to-six, 40-m1 capacity, glass Volatile Organic Analysis (VOA)vials and fitted with TeflonTM-lined screw caps. Care was taken to ensure that no air space existed in the vials by inverting, tapping, and checking for bubbles. Each =' container was properly labeled in the field and refrigerated for transport to Sherwood Labs in Hilmar for TPH-g by EPA Method 5030/8015-mod; TRPH-d analysis by EPA Method i 3510/8015-mod; and BTEX analytes by EPA Method 602. Appropriate chain-of-custody procedures were adhered to at all times during sample procurement and handling. The samples were extracted and analyzed within the lifespan limits set forth by EPA guidelines for the specified analyses. 4.3 Analytical Results Ground-water samples collected from the three wells were received at Sherwood Labs on June 21, 1994. The analytical results revealed wholly nondetectable concentrations of TRPH-d analytes and nondetectable results for TPH-g and BTEX analytes in samples collected from wells MW-4 and MW-5. The results of the analysis of the sample collected from MW-6 indicate that the ground water underlying that vicinity is significantly impacted with TPH-g and BTEX analytes well above the Maximum Comtamination Levels (MCLS) set by the California Department of Health Services. The analytical results for all initial ground-water sampling activities are summarized in Table 3. The Sherwood analytical reports and chain-of-custody are included as Appendix E. 5.0 SUMMARY Village West Marina is situated on organic, silty, and clayey sediments adjacent to Fourteen- ''=' Mile Slough in the Central Valley Geomorphic Province of California. Characteristics of _ the aquifers and occurrence of ground water underlying the site are typical for this portion of the San Joaquin Valley Ground-Water Basin in that the surface waters often represent the ground-water table. During the drilling of MW-4 through MW-6, saturated soils were encountered at an average depth of 18 feet bsg. Prior to purging and sampling the three ; i W.W. Irwin,Inc. Project No. 33016.03 July 1994 6