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I. 1 EXECUTIVE SUMMARY This report presents results from the limited soil and groundwater investigation as detailed in Kleinfelder's approved revised workplan dated May 23, 2003. The revised workplan included the installation of three groundwater monitoring wells, sampling and analyzing groundwater samples from the monitoring wells and domestic well on site, collecting and analyzing shallow soil samples from eight locations on the site, and conducting a geophysical survey for the possible presence of underground storage tanks (USTs). Three monitoring wells and eight shallow soil borings were advanced on the site. The three groundwater monitoring wells were installed on November 25, 2003. The monitoring wells were designated MW-1, MW-2, and MW-3; and the eight soil borings were designated B-1 through B-8. (see Plate 3). Groundwater samples were collected from the three monitoring wells and the domestic water supply well on site on December 2, 2003, and a geophysical survey was completed in the area of the suspected UST(s) on November 19, 2003. The groundwater flow direction was calculated to be towards the northwest with a gradient of 0.001 feet/foot. Kleinfelder collected shallow soil samples from the eight locations designated as the vehicle parking areas, ground surface depression near the eastern edge of the site where stormwater runoff concentrates, in areas of former above ground storage tanks (ASTs), tank wash out area, and the residence leach field. Additionally, soil samples were collected during the advancement of the soil borings for the installation of the monitoring wells on site. The results of the shallow soil sampling and analyses conducted from the various portions of the site showed low concentrations of 4,4-DDD, 4,4-DDE, 4,4-DDT, Dieldrin, and Oryzalin. Additionally, The soil samples collected from the borings advanced for the monitoring wells showed low concentrations of 4,4-DDD, 4,4-DDE, 4,4-DDT, Dieldrin, and Endosulfan I. Each noted constituent from within the monitoring well soil borings diminished in concentration with depth, many to non-detectable concentrations. There were no detectable pesticides, Carbamates, or organophosphates in MW-3 soil samples. The metals analyses of each of the soil samples showed each metal included for analyses to be below the Preliminary Remediation Goals PRGs and/or within the range of naturally occurring background concentrations in California with the exception of arsenic, which concentrations in the shallow soil samples exceeded the cancer end point PRG of 0.39 mg/kg but did not exceed the non-cancer end point PRG of 22 mg/kg. All of the reported concentrations were below the respective residential PRGs for the additional noted constituents. The results of the soil samples for fertilizer constituents showed relatively higher concentrations (compared to the other soil samples collected and analyzed at the site) of TKN and nitrate as NO3 in the soil samples collected from near the tank washout and rinseate collection sump/tank (B-1), former fuel above ground storage tank (B-7), and below the tank washout concrete pad (B-8). The concentrations of TKN ranged from 500 mg/kg (B-1-1') to 3,600 mg/kg (B-1-1'). The concentrations of nitrate as NO3 ranged from 80 mg/kg (B-1-1') to 460 mg/kg (B-8-3'). 27125.E01 /STO4R181 Page 1 of 23 © 2004 Kleinfelder, Inc. February 13, 2004 KLEINFELDER 2825 East Myrtle Street, Stockton, CA 95205-4794 (209) 948-1345 (209) 948-0621 fax