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revealed in the collected samples of soil or groundwater Analytical results of soil samples Y p collected from ASB-1 were wholly nondetectable Based on these results, Water Warks 1 concluded that waste-oil contamination did not appear to spread laterally beneath the on-site building On December 15, 1989, soil was overexcavated from the western wall near the former diesel UST area Laboratory analytical results revealed a TPH-d concentration of 30 6 ppm at 6 feet, TPH-d was not detected in samples collected at depths of 2 feet or 16 feet ' Ground-water samples collected from M - P W 1 in February of 1990 indicated a TPH-d concentration of 350 ppm A TPH-d concentration of 59 ppm was detected in a sample collected two months later in April of 1990 On September 27, 1993, Roger Foote Associates (RFA) of West Sacramento drilled three soil borings, two of which were converted to ground-water monitoring wells, MW-2 and MW-3 Soil boring ASB-2 was drilled at an angle of about 30° to vertical and was extended to an equivalent vertical depth of 33 5 feet Both monitoring wells were completed to a total depth of 50 feet ' Selected soil samples were analyzed for TPH-d, TPH-g, and BTEX constituents by California Laboratory Services of Rancho Cordova, a State-certified analytical laboratory Soil samples collected from ASB-2 Q 6 & 19 feet, MW-2 @ 15, 35 & 40 feet, and MW-3 @ 35 & 40 feet below surface grade (bsg) were found nondetectable for all constituents Ground water was encountered at an average depth of 45 feet bsg I W W Iran, Inc of Merced was awarded the contract to perform ground-water monitoring by Ms Carmen Punla in January of 1995 Monitoring wells MW-1 through MW-3 were first sounded and sampled by W W Irwin, Inc on February 6, 1995 Mr Harlin Knoll of the San ' Joaquin County Division of Environmental Health has attended all scheduled monitoring activities Ground-water monitoring was also performed on May 9, August 11, and November 30, 1995 GROUND-WATER MONITORING - APRIL 2, 1996 ' Ground-Water Soundings ' The last SJCPHD-EHO-required ground-water monitoring activity was conducted on April 2, 1996 Utilizing a Keck® interface probe, the W W Irwin, Inc staff geologist determined that the average, piezometric depth-to-water underlying the site was 28 19 feet bsg The water table ' underlying the site has risen 3 41 feet in the 4-month period since November 30, 1995 when the average depth to water was 31 60 feet bsg W W Irma Inc Projects 33236 00&33236 01 April 1996 3