ARCHIVED REPORTS_PHASE I ENVIRONMENTAL SITE ASSESSMENT AND LIMITED SUBSURFACE INVESTIGATION

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NO Winston#209 Manteca,CA August 8,2002 .. 5.0 PHYSICAL SETTING 5.1 REGIONAL TOPOGRAPHY SECOR reviewed the United States Geological Survey(USGS)7.5-minute topographic map for the Manteca,California quadrangle,dated 1991. Topography in the vicinity of the Site is relatively flat, with slight relief to the southwest. According to the map,the Site is at an elevation of approximately ` 35 feet above mean sea level. The San Joaquin River is the closest surface water body, located approximately 5.0 miles southwest of the Site. There were no perennial surface water bodies observed on the Site,however there is a small ponding basin located on the vacant lot to the east of the Site. The basin was dry at the time of SECOR's site visit. 5.2 LOCAL GEOLOGY Soil borings at the Site indicate the soils beneath the Site consist of sand and gravel from beneath the concrete baserock/asphalt to approximately 2 feet below ground surface (bgs), underlain by brown to dark grayish brown sand and silty sand from 2 to 12 feet bgs(total depth). Field boring logs are included in Appendix E. 5.3 LOCAL HYDROGEOLOGY Based on information provided by California Department of Water Resources,the depth to the first groundwater beneath the Site is typically approximately 20 feet in the vicinity of the subject property. Based upon the regional topographic slope,the direction of groundwater flow is assumed to be southwest. Groundwater was not encountered in the soil borings completed as part of the Limited Subsurface � Investigation on the subject property. V r r 0042 gy store 209 phase 2 reviewedl SECOR International Incorporated 9