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I k4 KLEINEELDER collected from MW-1 and MW-3. A groundwater sample collected from perimeter monitoring well MW-4 was reported to contain TPH-G and three oxygenates TBA, MTBE and TAME. TPH-G was detected in this groundwater sample at 0.56 milligrams/liter (mg/1). MTBE was detected at 790 micrograms/liter (µg/1) and TBA was detected at 150 µg/1. The oxygenate TAME was detected at 1.5 µg/1. Based on the groundwater elevation data monitoring well MW-4 is located downgradient to the former Shell Station. Based on these findings it appears that the current and or past operation of the adjacent gas station are impacting groundwater beneath the northern portion of the site. The MTBE concentrations detected in MW-4 (790 µg/1) were found to exceed State Primary and Secondary Maximum Contamination Limits for Drinking Water Standards of 13 and 5 µg/1. u No petroleum constituents were detected in groundwater amples collected from monitoring well MW-2, located in proximity to the former onsite UST area or from MW-1 which is situated downgradient of the former UST location. Based on this data, it does not appear that the former UST operations have impacted groundwater beneath the farmer UST area. 5.2.2 Soil Sampling Results (near surface soil sampling) WASH DOWN AREA E Two 4-point composite samples and five discrete soil samples were analyzed for metals, petroleum constituents, organophosphate pesticides, organochlorine pesticides and herbicides in the wash down area. Table 3 summarizes the metal concentrations in this area and Table 6 summarizes the remaining analyses as listed in Section 4.6.1. Petroleum constituents and metals 2 were the only analytes detected in both composite and discrete soil samples collected in this area at relatively shallow depths of approximately 18-inches bgs. A deeper soil sample (W9) was collected near the wash down area in proximity to a reported sump. This deeper sample was collected from a shallow boring in which near surface soil was noted to be discolored with petroleum-like odors. The deeper soil sample was reported to be non-detect for the requested petrolemn constituents. TPH-D and/or TPH-MO were detected in two composite soil samples and three discrete soil samples. TPH-G and BTEX constituents were not detected in the soil samples collected in this area. TPH-D concentrations ranged from 4.2 to 16 mg/kg. TPH-MO ranged from 4.0 to 52 mg/kg. The highest TPH concentrations were reported in a 4-point composite sample collected from four discrete samples collected near the northern perimeter of the wash down area. i Two composite soil samples and four discrete soil samples collected in the wash down area were also analyzed for 17 metal (See Table 3). Eleven of the seventeen metals including arsenic, barium, beryllium, chromium, cobalt, copper, lead, mercury, nickel, thallium and zinc were detected in one or more of the soil samples. 4 These results were compared to the California Code of Regulations 22CCR§66261.24 and/or the Residential and Industrial U.S. EPA Region IX Preliminary Remediation Goals (PRGs), dated October 2002. 36274/ST03R1919 Page 12 of 19 g,2004 Kleinfelder, Inc. January 5,2004