ARCHIVED REPORTS XR0004137 - Laserfiche WebLink

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' PROPOSED CLOSURE PLAN Beacon Station No 696 2448 West Kettleman Lane Lodi, California Delta Project No 40-93-916 Page 2 3.0 PROPOSED CLOSURE PLAN ' 3.2 Soil Boring Locations Delta recommends drilling and sampling of four soil borings to a depth of 50 feet below grade to assess the efficiency of vapor extraction, and to confirm that no further remediation is warranted at the site Soil borings would be located to the north, east and west of the previous underground fuel storage tank location, and at one off-site location The soil boring on the west side of the previous tank location ' would be angled 35° off vertical toward the east in order to collect soil samples from below the former tank pit The proposed soil boring Iocations are shown in Figure 3 A cross-section location map is ' included as Figure 3, and cross-sections A-A' and B-B' are presented in Figures 4 and 5, respectively Included in the cross-sections are protections of the proposed soil borings, and any available analytical ' results for soil samples collected during installation of wells located on the sections 3.2 Soil Sampling Soil samples will be collected from each boring at 5-foot intervals and will be field-analyzed for the ' presence of organic vapors with a photoionization detector (PID) Soil samples collected from depths of 10, 20, 30, 40, 45, and 50 feet below grade will be submitted for laboratory analysis of benzene, toluene, ' ethylbenzene, and xylenes (BTEX), and TPHg using methods approved by the U S Environmental protection Agency and the California Department of Health Services The sampling methods and a ' quality assurance plan are presented in Appendix A ' 4.0 CLOSURE San Joaquin County Environmental Health Division will grant regulatory closure of the site if laboratory analyses indicate that no soil sample contains concentrations of TPHg greater than 10 parts per million (ppm), benzene greater than 0 005 ppm (analytical method limit of detection),toluene greater than 1 0 ppm, ethylbenzene greater than 0 68 ppm, or xylenes greater than 1 75 ppm The rational for the use of these limits is if 100 percent of the BTEX in soil at these concentrations were mobilized into ' ground water, the Maximum Contaminant Levels established by the California Department of Health Services and the U S Environmental Protection Agency would not likely be exceeded If the concentrations of BTEX or TPHg in soil exceed the proposed maximum allowable concentrations, a I ' RPT066 TA