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OT/1O/% Pam _off .� Va a La(KOOvion and Des¢ri�pvo�n 4he sub'ect site i I s p®sated an downtown [L®ckeforcl, CA. pt was previously anseel ®s a gasoline service station which housed four pump dispensers with associated piping, three gasoline USTs, and one waste oil UST. Most off the site is covered by asphalt except for the concrete slab under the building and in the vicinity of the former dispenser islands. The site is basically flat and surfface drainage appears to flow vo the alley way at the rear of the property. 1.2 PcIsv ➢r�vesvic�c�vi®ns Three gasoline [SSTs were removed �roav one pit and one waste oil UST was removed from another pit on July 19, 1991. Soil sampling of the pits and soil waste stockpiles ensued immediately thereafter. The pits were backfilled with 'h inch pea gravel and the waste soil was manifested offsite by Contaminated Soil Hazardous Waste Mauler, Erickson Inc., of Richmond. 4he main indicator chemical for gasoline, benzene, was found at very pow levels in the soil (i.e. no higher than 2.3 ppm) in the vicinity of the former gasoline RASTs. No benzene was identified in the vicinity of the forever dispensers and associated piping. No PCBs air chlorinated solvents were found to be associated with the forever waste oil tank. Some metals were found; � however, none could be considered to be as risk due to Qhe low concentrations idlentigied. Geosoly, dQC paergormed a subsur%ce soip investigation and the results were reported in the September 08, 1997 subsurface investigation report. The results of the report indicated that the site had been contaminated by low levels of TPHg gasoline relative to very low levels of volitiles such as benzene. This is indicative of old gasoline which is a minimal to no threat to health health and water supplies (i.e. excluding taste and odor threshold). 1.3 give MVdJr®Ze®p®Oy The site fees within the Eastern Son Joaquint)►County Basin which has had problems with overdraft in the past. The Mokelumne River is located approximately one mile to the north and to the west of the site and the intermittent Bear Creek runs approximately 3/4 of a mile to the southeast of the site. The site lies over a deep alluvial basin composed of shallow sandy clays with a hard pan and deeper sands. Regional groundwater, in the vicinity of the site, lies at a depths below ground surface (bgs) between 89 to 117 feet bgs. Groundwater was encountered in the borehole excavated to 100 feet bgs at 96.4 feet bgs (See Viguve 1 for lithola & dross sectaon).