Laserfiche WebLink
sw� <br /> 1OO Pine Street, 1 Oth Floor <br /> San Francisco, CA 94111 GEOMATRM <br /> (41 E5) 434-9400 - FAX (415) 434-1365 <br /> February 17, 1999 <br /> Project C3499.01 <br /> Ms. Katie Hower <br /> Chevron Pipe Line Company <br /> P.O. Box 6059 <br /> San Ramon, California 94583 <br /> Subject: Soil and Groundwater Investigation.Report and Site Closure Request <br /> Dobler Property(San Joaquin County APN 209-270-26) <br /> 13588 West Grant Line Road <br /> Tracy, California <br /> Dear Ms. Hower: <br /> Geomatrix Consultants, Inc. (Geomatrix), is pleased to submit this Soil and Groundwater <br /> Investigation Report and Site Closure Request for the Doblcr Property(San Joaquin County <br /> APN 209-270-26; Figure 1),prepared on behalf of Chevron Pipe Line Company(CPL). Field <br /> activities were performed in accordance with CPL's 21 August 1998 work plan which was <br /> submitted to and approved by the San Joaquin County Public Health Services (SJCPHS). This <br /> work plan was developed using the approach outlined in"Technical Approach to Site <br /> Evaluation and Decision Making, Old Valley Pipelines Sites, Central Valley Region" <br /> (Technical Approach) to assess the possible presence of petroleum hydrocarbons on the Dobler <br /> Property that may be associated with CPL's Old Valley Pipeline(OVP). <br /> FIELD INVESTIGATION <br /> Three soil borings (B-1, B-2 and B-3)were advanced at the site by Precision Sampling Inc. <br /> (Precision), of San Rafael, California on 22 October 1998 (Figure 2). Prior to drilling, <br /> Geomatrix obtained a soil boring permit from the SJCPHS;notified Underground Service <br /> Alert; and contracted Cruz Brothers Sub-Surface Locators,Inc., of Milpitas, California, to <br /> perform an underground utility clearance at the proposed borings locations. Soil borings were <br /> advanced to a depth of 15 feet below ground surface (bgs) using a hydraulically driven, direct <br /> push drive sampler and continuous core barrel. <br /> Soil cores were examined and logged by Geomatrix(Appendix A), and one soil sample was <br /> collected from each boring at either the area of soil core most visibly affected by petroleum <br /> hydrocarbons, or just above the groundwater table if no petroleum hydrocarbons were <br /> observed. Petroleum hydrocarbon-affected soil was observed in boring B-1 from depths of <br /> approximately 8.5 to 9.5 feet bgs, accordingly,the soil sample from B-1 was collected from a <br /> depth of 9.5 feet bgs. No petroleum was observed in borings B-2 or B-3; soil samples were <br /> Geomatrix Consultants, Inc. <br /> Engineers, Geologists, and Environmental Scientists <br />