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Mr Edward C Ralston March 13, 2001 Page 3 • Soil Selection and Analysis. Soil samples were collected every five vertical feet in the monitoring well borings Selected soil samples, based upon field observations, were submitted to Sequoia Analytical, a California State-certified laboratory and analyzed for the presence of TPH-g, benzene, toluene, ethylbenzene, and total xylenes (BTEX), and MtBE by EPA Methods 8015 Modified and 8020 Samples with positive MtBE detection by EPA Method 8020 were analyzed for MtBE, 1,2-dichloroethane (1,2-DCA) and ethylene dibromide (EDB) using EPA Method 8260 Total lead analysis by EPA Method 6010 was also conducted on samples analyzed by EPA Method 8260 Soil samples collected from the capillary fringe and from the bottom of each boring and the samples with the highest PID detection in each boring were analyzed TPH-g was detected in nine soil samples ranging from 2 35 to 473 mg/kg Benzene was detected in five soil samples ranging from 0 0204 to 0 852 mg/kg MtBE was detected in soil sample MW-6(20') at a concentration of 0 119 mg/kg (by USEPA 8260) 1,2-DCA, EDB, and total lead did not exceed laboratory detection limits Soil sample analytical results are presented M Table 1 Copies of certified analytical reports and chain of custody documents are presented in Attachment C • Groundwater Sampling and Analysis. On January 8, 2001, Gcttler-Ryan, Inc collected groundwater samples from the new monitoring wells and from the four previously installed on-site monitoring wells Groundwater samples were submitted to Sequoia Analytical and analyzed for the presence of TPH-g, BTEX, and for five oxygenates (MtBE, Dl-isopropyl ether [D1PE], Ethyl tert butyl ether [ETBE], Tert-amyl methyl ether [TAME] and Tertiary butyl alcohol [TBA]) using EPA Methods 8015 Modified, 8020 and 8260, respectively Groundwater monitoring well samples were also be analyzed for 1,2-DCA and EDB using EPA Method 8260 Upgradient monitoring well MW-8 defines the southern extent of groundwater impacts TPH-g, benzene, and oxygenates were not detected Toluene, ethylbenzene, and total xylenes were detected at concentrations less than 5 parts per billion (ppb) Downgradient monitoring wells MW-5, MW-6, and MW-7 and cross-gradient monitoring well MW-9 contained dissolved petroleum hydrocarbons TPH-g concentrations ranged from 29,000 to 72,000 ppb Benzene concentrations ranged from 62 to 250 ppb MtBE concentrations reported by EPA Method 8260 ranged from less than 20 to 750 ppb Highest detected petroleum hydrocarbon concentrations were detected in the sample from monitoring MW-6, located approximately 70 feet downgradient of the USTs 911005 1C/1205wp_0301 doe IT CoipomtAoa