ARCHIVED REPORTS_XR0002322 - Laserfiche WebLink

Home Browse Search

Environmental Assessment Report 3 Chevron V 5 A Products Company, 575 West Grantlme Road, Tracy, CA .. June 29, 1995 Completed wells were surveyed by Morrow Surveying for horizontal position and elevation relative to mean sea levet datum using previously surveyed monitonng wells on site as a reference (Appendix C) Elevations were obtained for top-of-well-casing and the well box nm for each well On May 12, 1995,the new wells were manually developed by Groundwater Technology using a surge block and bailer in order to remove fine-grained sediment Pnor to development activities,depth to water was measured in each new well relative to top-of-well-casing to determine the static water level (Table 1) The new wells were manually developed using a surge block and bailer in order to remove fine-grained sediment Approximately 30 gallons of water were extracted from each well (equivalent to 14 well volumes) All water generated during development was pumped Into a U S Department of Transportation-approved purge water trailer and transported to the Chevron refinery in Richmond, California for recycling 3,0 RESULTS OF SOIL SAMPLE ANALYSES Tables 2 and 3 summanze the laboratory analytical results for soil samples collected on May 2, 1995 Table 2 presents data on BTEX and petroleum hydrocarbons The highest concentrations of benzene and TPH-G were detected in the sample collected at 6 5 feet BGS from boring MW-3 at concentrations of 24 and 7,600 milligrams per kilogram (mg/kg, equivalent to parts per million, or ppm), respectrvely • The maximum concentration of TPH-D, at 190 kg/mg (described as unidentified hydrocarbons)was detected in the sample collected from the 6 0-foot depth from boring MW-4 The highest concentration of total oil and grease was detected in sample MW-1-6 0 at 27 mg/kg Concentrations of extractable organics (EPA method 8270), and cadmium in samples collected from the 6 0-and 11 5-foot depths from boring MW-1 were below laboratory detection limits (Table 3) Levels of lead, nickel and zinc detected in these samples were all below comparable Soluble Threshold Umd Concentration (STLC) limits Total chromium was detected in sample MW-1-11 5 at a concentration of 35 mg/kg, which is less than the STLC limit of 50 ppm for chromium VI Copies of laboratory analyses reports and chain-of-custody manifests for the soil samples collected May 2, 1995 are included in Appendix D • 013BEAR RPTIGAv 112] DOW GROLNDWAM 01111naiNot,wy