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t = '.'november 24, 1997 Page 4 . sensitive receptor survey also proposed in the lVork Plan will follow shortly under separate cover. The specific scope of work for each item is Iisted below: • Monitoring Well Installation. Two groundwater monitoring wells (MW-8 through MW-9) were installed at the general locations shown on Figure 2. Well MW-8 was installed south-southeast (downgradient) of the site and Well MW-9 was installed onsite immediately southeast of the former USTs. Wells MW-8 and MW-9 were installed to depths of 42 and 56 feet bgs, respectively. The boring for MW-9 was extended to 80 feet in order to define the vertical extent of the hydrocarbon impacted soil. The purpose of the wells was to define the extent of gasoline hydrocarbons in groundwater downgradient of the site and vertically adjacent to the former UST complex. • Soil Selection and Analysis. Soil samples were collected every five vertical feet. Selected samples were submitted to a California State-certified laboratory and analyzed for the presence of TPH-g, BTEX, MtBE, and oxygenates. Additionally, selected samples were analyzed for water content, bulk density, porosity, and fractional organic carbon content. Groundwater Analysis. After well development, water samples were collected from the wells and submitted to a California State-certified laboratory for analysis. Groundwater samples were analyzed for the presence of TPH-g, BTEX compounds, and MtBE. SUMMARY OF FINDINGS • Soils encountered in Wells MW-8 and MW-9 consisted primarily of clayey silt, sandy silt, silty clay, and silty sand. Groundwater was encountered at a depth of approximately 30 feet and stabilized at approximately 28 feet bgs. Stratigraphy and well construction infonnation are presented in Attachment A. • Well MW-8 reported nondetectable levels of the analyzed compounds in soil. In Well MW-9 TPH-g was reported in soil at concentrations ranging from 6,200 ppm at 35 feet bgs to nondetect at 70 feet bgs. In Well MW-9 benzene was reported in soil at concentrations ranging from 110 ppm at 35 feet bgs to nondetect at 70 feet bgs. Maximum concentrations of toluene, ethylbenzene, and total xylenes were reported at 35 feet bgs in MW-9 at 450, 150, and 640 ppm, respectively. Methanol was reported at 62 feet bgs in Well MW-9 at a concentration of 300 ppm. No other oxygenates were detected in this sample. Additionally. no methanol or other oxygenates were detected in the sample collected from a depth of 25 feet bgs. 920-078.1 A/SOLG WRPT