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r� Drilling, Sampling,Completion, and Development of Initial Monitoring Wells :.; On June 6, 1994, soil borings 4, 5, and 6 were drilled and completed as groundwater monitoring wells MW-4, MW-5, and MW-6. This sequence of well numbers was selected in order to avoid confusion regarding the previous HydropunchTM numbers HP-1, 1HP-2, and HP-3. The monitoring well locations are depicted on Figures 2 and 3. Ij Monitoring wells MW-4, MW-5, and MW-6 were first sounded on June 24, 1994. W W. Irwim Inc. contacted the piezometric surface in each well at an average depth of 14.82 feet bsg. The sounding depths were converted to groundwater elevations utilizing weft casing-top elevations established on June 13, 1994 by Duane Kimball, Modesto-based, California-licensed Land Surveyor No. 4378. Groundwater samples collected from MW4, MW-5, and MW-6 were received at Sherwood Labs on June 21, 1994. The results of the analysis of the sample collected from MW-6 indicated that the groundwater underlying that vicinity was impacted with TPH-g and BTEX analytes exceeding the Maximum Contamination Levels(MCLs) set by the California Department of Health Services. Groundwater Monitoring Activities The SICPHS HHS required that groundwater monitoring and the recording of tidal data be undertaken 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 (WW. Irwin, Inc., January 30, 1995) contained data which, until the Problem Assessment Report was issued on August 8, 1995, were the most recent up to that time regarding site conditions at Village West Marina. F Problem Assessment and Completions of MW-7 and MW-8 G`=>3 On July 3, 1995, W.W. Irwin, Inc. directed the drilling, logging, and sampling of Hydropuncheem HP-7, HP-8, HP-9, and HP-10. HP-7 and HP-8 were completed as monitoring wells MW-7 and MW-8. E� 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 jactivities 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. had recommended bioventing with continued groundwater monitoring as is the best, cost-effective technologies for cleanup of affected soil and groundwater. 200541.496 3 HORIZON ENVIRONMENTAL INC. E