ARCHIVED REPORTS XR0007673 - Laserfiche WebLink

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Firestone Tire and'ubber Company Page 3 Stockton, CA , work Plan ASSESSMENT Based on the analytical results reported and summarized in Table 2 , the Tank 5 and Tank 16 area are the two sites proposed for further assessment . The purpose of the site assessment work will be to determine the vertical and horizontal extent of contaminants, if any, in soil at each of Tank 5 and Tank 16 site. ' Tank The chemicals of concern at this tank site are Total Petroleum ' Hydrocarbons (TPH) and benzene, toluene, ethylbenzene, and xylene (BTX&E) It is proposed to drill two borings, as shown on Figure 2, to a maximum of 40 feet This depth is approximately 30 feet below the invert of the tank If clay is encountered, as reported at the site, it is expected that the clay strata would have limited the extent of the release from the tank site. Additionally, it is proposed to visually inspect electrical and ' telephone vaults, catchbasins, and available sewer manholes within the property boundary of the Firestone facility along N El Dorado St and Lindsay St for evidence of chemicals that may have migrated from the tank site through the utility trenches During the drilling work, soil samples will be retrieved at five foot intervals beginning at five feet below grade If the soil strata encountered during the drilling work is not clay, or there are interspersed lenses of sand or other permeable layers noticed during the drilling work, soil samples will be taken at the bottom of the interface between the permeable layer and clay strata Soil samples will be analyzed for TPH as gas, TPH as motor oil, and BTX&E Confirmation soil samples at final boring depth will determine if additional investigative work will be required at the site ' Tank 16 The chemicals of concern at this tank site are Total Petroleum Hydrocarbons (TPH) as motor oil It is proposed at this site to ' over excavate backfill and native material by incremental depths of 3 feet . The soils in this area are brown clay-like and, since the type of hydrocarbon reported in the laboratory analysis (motor oil) does not migrate readily through soils, it is expected that excavation will remove the TPH encountered at this tank. ' During the work, confirmation soil samples will be taken at the side walls and bottom of the excavation Soil samples will be analyzed for TPH as motor oil If the excavation extends to 16 ' feet with continuing detection of TPH above 100 mg/kg, then consideration will be made by Firestone to perform exploratory drilling to assess the vertical and horizontal extent of the ' hydrocarbon release at the Tank 16 site