Laserfiche WebLink
Phase II Site Assessment Workplan/Health and Safety Plan October 1999 <br /> for the Hammer Lane/Highway 99 Interchange Improvement Project Project No. H2O2 <br /> an automobile sale lot. There is an existing structure that appears to be that of the former <br /> service station building. The remainder of the site area is covered by asphaltic or portland <br /> cement concrete. The former Mobil Oil site is currently unused and the structures from the <br /> former service station have been removed. Weathered asphaltic and portland cement concrete <br /> cover the majority of the site. <br /> Geologic conditions consist of Pleistocene alluvial deposits. The alluvium is expected to <br /> consist of interbedded, poorly graded to well graded sand, medium dense, silty sand, sandy <br /> silt, sandy clay and clay. <br /> Nearby site investigations and ground water maps produced by the San Joaquin County Flood <br /> Control and Water Conservation District indicate that ground water may be encountered at a <br /> depth of approximately 60 feet below the ground surface. The general ground water gradient <br /> appears to be to the south-southeast. <br /> Espana Geotechnical Consulting performed a shallow subsurface investigation at these sites <br /> during February, 1999 which did not reveal the presence of contamination at the depths <br /> studied. No other known on-site subsurface investigations have been conducted for these sites. <br /> Purpose of This Study <br /> This proposed subsurface investigation is based on the request of Caltrans District 10 personnel <br /> to provide an additional subsurface investigation in the vicinity of the former underground fuel <br /> tanks at the former Texaco and Mobil Oil sites to determine if contamination exists in these <br /> areas. These lands may be acquired by Caltrans for interchange improvements. <br /> The proposed drilling and sampling program is to identify hazardous wastes that may be <br /> present on the subject site at the former underground fuel tank locations. In the process of the <br /> investigation, should we encounter hazardous constituents in quantities above San Joaquin <br /> County acceptable limits, it would be necessary to define both the lateral and vertical extent <br /> of that contamination. This subsurface investigation is intended only to address the existence <br /> or non-existence of soil and/or ground water contamination at the subject locations. <br /> Drilling <br /> Drilling and sampling is proposed at the approximate locations shown on Sheets 1 and 2. <br /> These boring locations may require minor modification in the field due to progressive findings, <br /> utilities, and physical barriers. Soil samples will be collected for analysis. <br /> Augered borings will be drilled using 8-inch diameter hollow-stem augers. Cuttings will be <br /> continuously logged by a registered geologist or civil engineer in accordance with USCS <br /> 2 <br /> ,`I ESPANA GEOTECHNICAL CONSULTING <br />