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N./ i,..y recorded an average water table depth of about 70' bgl. It was measured at an average depth of 59.01' bgl in July, 1998. LOCATION OF WELLS WITHIN 2,000 FEET OF PROPERTY: The attached EXHIBIT A lists wells identified by the California Division of Water Resources. Field investigation reveals that the list is incomplete. We have completed a survey of the area to locate existing wells. The results of that survey are shown on PLATE I It shows allot the wells which were visible from close observation; there may be others which could not be identified. PRIOR USE OF UST'S: Two, 5,000 gallon UST's which had been used for storing diesel fuel were removed from the property in March, 1987. There are no records concerning amounts of fuel used during the time the tanks were in service. SUMMARY OF PRIOR EVENTS: March, 1987 - Two 5,000 gallon diesel UST's removed from site. Some contamination measured in soil samples taken after tank removal. March, 1988 - Site of removed UST's reentered. Soil samples taken at 28'& 29' below grade. Xylene& TVPH measured in both samples. Excavation filled with clean soil. April 3, 6, & 7, 1992 - Three (3) groundwater monitoring wells placed on site to depths of 84', 86', & 89'. Refer to WJH report titled "Groundwater Investigation Report"dated May, 1992 for details of that work. May 30, 1996 - One(1) soil boring was advanced to 80' bgl; it was located in the area which had been occupied by the diesel UST's. Minor amounts of ethylbenzene were measured at 31', 36',41',& 56'. Low levels of xylene was detected at 311, 361, 411, 461, 511, 56,61', & 71'. TPH as gasoline was measured in samples taken from 31' to 71', and at 80'. Significant levels of TPH as diesel were measured in all samples taken. TABLE I summarizes the results of that work, and also MW-1 & MW-4. Refer to the Lush Geosiences report titled "Interim Investigation Report Marci's Diesel Service", dated August 17, 1996 for details. October 10, 1996 - MW-1 was purged and sampled by Del-Tech Geotechnical Support Services, but the laboratory results were considered inaccurate due to apparent contamination of sampling equipment. November 27, 1996 -MW-1 was resampled by Del-Tech. Laboratory results revealed the following; benzene-ND, toluene -ND, ethylbenzene- 0.4 ug/L, xylene - 0.8 ug/L, and TPHg - 222 ug/L. TEPH was ND, and MTBE was not identified. 2