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Chevron U.S.A. Page 32 Each of the recently constructed monitoring wells were developed and sampled on April 11th and 12th of 1990. The test results revealed no contamination except for only low levels in monitoring well MW-2A. This result was significantly less than the contamination of monitoring well MW-2, approximately 5 feet from the newly constructed MW-2A. In ar,attempt to sample MW-2, Dames&Moore observed that the well had been contaminated by hydrocarbon products entering from the surface through a poorly sealed well head. This contamination was possibly arising from vehicles parked over the monitoring well. Monitoring well MW-2 could not be sampled since it had gone dry,due to the lowering water table. Additional rounds of sampling in May and August of 1990 revealed the same, relatively low petroleum contaminated groundwater in the recently constructed deeper monitoring wells, including MW-2A. At Chevron's request, Dames&Moore reconstructed the Christy-box and well head -R of the older monitoring wells MW-1, MW-2, MW-3, MW-4, MW-5, MW-6, and MW-7, FC! 11.0 CONCLUSIONS Based on the review of the data collected from Dames&Moore's investigation at the subject property and the review of readily available published and site data, we { have summarized the following general conclusions for your considerations: o The soils encountered at the subject property have a stratigraphy resulting with relatively low permeability materials over the surface 10 to 15 feet, with a more sandy, permeable stratigraphy occurring from approximately 10 to 30 feet below the surface. o Monitoring well MW-2,constructed in 1986,and historically with the highest reported contamination, has recently gone dry. Monitoring well MW-2A replaced this well. Test results of groundwater from monitoring well MW-2A show only low levels of contamination. 36000-206-0+4