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ARCADIS Ms. Kathy Amaru <br /> October 19, 2010 <br /> • Moisture content by American Society for Testing and Materials(ASTM) Method <br /> D-2216(so that results can be presented on a dry weight basis) <br /> The primary samples were additionally analyzed for benzene, toluene, ethylbenzene <br /> and xylenes(BTEX) by USEPA Method 8021 B. <br /> Four of the samples submitted for laboratory analysis contained concentrations of <br /> target analytes above RWQCB ESLs. The three primary samples containing <br /> concentrations above screening levels were collected from two borings, SB-02 and <br /> SB-04. The sample collected from 5.5 to 6 feet bgs in boring SB-02 contained a TPH <br /> as motor oil concentration of 210 milligrams per kilogram (mg/kg), which is above the <br /> ESL of 83 mg/kg. Two samples collected from boring SB-04 (from 5.5 to 6 and 7.5 to <br /> 8 feet bgs) contained TPH as gasoline, TPH as diesel and TPH as motor oil <br /> concentrations as high as 8,200 mg/kg. One contingency sample collected from <br /> boring SB-13 (from 5.5 to 6 feet bgs)contained a TPH as motor oil concentration of <br /> 190 mg/kg. <br /> No other soil samples evidenced detections of target analytes above laboratory <br /> reporting limits, or analytes were detected at concentrations below respective <br /> screening levels. The Site Sampling and Soil Removal Work Plan(ARCADIS, 2010a) <br /> proposed the collection of grab groundwater samples from three borings; however, <br /> groundwater was not encountered in any borings at 8 feet bgs. Therefore, no grab <br /> groundwater samples were collected. Results from the April 2010 sampling event are <br /> presented in the Excavation and Sampling Work Plan(ARCADIS, 2010b). <br /> Soil Removal and Confirmation Sampling <br /> As described in the Site Sampling and Soil Removal Work Plan and the Excavation <br /> and Sampling Work Plan, ARCADIS expanded the existing excavation and removed <br /> additional impacted soils based on the April 2010 soil sampling results. The intent of <br /> the expanded excavation was to remove impacted soil in the direction of former <br /> borings SB-02, SB-13 and SB-04 which contained concentrations above ESLs. <br /> Removal Activities <br /> Prior to soil removal, the underground utilities were surveyed by a private, third-party <br /> utility locator. If subsurface interferences were located the utility was identified using <br /> hand tools (e.g., shovels) and an air knife/vacuum truck. Soil was then removed <br /> using a small backhoe (make/model: CAT 430E). Removed soils were field screened <br /> Page: <br /> anmin75aa 3/12 <br />