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Environmental Assessment Report 3 Chevron U S A Products Compete 103 West 11th Street Tracy CA April 26 1995 presented on the drilling log (Appendix B) Figure 1 shows the location of MW4 and MW -5 relative to previously installed monitoring wells at the site Subsequent to drilling activities in boring MW -5, and during installation of the monitoring well in this boring, the operator of the buvness adjacent to MW -5 contacted the Groundwater Technology, Inc representative and drill crew on site to inform them of a possible break in a sewer branch connecting his business with the main sewer line in the street Close examination of boring MW -5 revealed a damaged 4 -inch -diameter clay sewer pipe located at the outer edge of the boring approximately 2 5 feet BGS On March 20, 1995, Groundwater Technology personnel repaired the damaged section of sewer pipe under the supervision of Mr Avtar Barisal, City of Tracy Department of Public Works Construction Inspector Completed wells were surveyed by Morrow Surveying for horizontal position and elevation relative to mean sea level datum using previously surveyed monitoring wells on site as a reference (Appendix C) Elevations were obtained for top -of -well -casing and the well box nm On March 23, 1995, MW -4 and MW -5 were developed by Groundwater Technology using a PVC bailer Prior 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 20 gallons of water was extracted from wells MW -4 and MW -5 (equivalent to 11 and 10 well volumes, respectively) All of water generated during development was pumped into a U S Department of Transportation -approved purge water trader and transported to the Chevron refinery in Richmond, California for recycling 30 RESULTS OF SOIL SAMPLE ANALYSES Table 2 summarizes the laboratory analytical results for soil samples collected on March 20, 1995 TPH-G and BTEX were not detected in any of the analyzed sod boring samples or stockpile samples Copies of laboratory analyses reports and chain -of -custody manifests for the sod samples are included in Appendix D 0055EAR RPTIChv.471 ❑�.❑W GROUNDWATM ❑❑❑ TECHNOLOGY .