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Clayton <br /> Ifl\ a\ <br /> When KEI installed the groundwater monitoring w411 (whitih has been <br /> abandoned) near the former location of the UST in 1986,groundwater was <br /> analyzed for gasoline, benzene, toluene, ethylbenzene, and xylene, all of which <br /> mere below detestable limits Clayton reviewed the report genctated from that <br /> study and found that the location plan included in the report was Somewhat <br /> misaligned It appears that they probably installed the well on the south, or <br /> upgradient, side of the UST I his might explain why they did not find detectable <br /> limits of hydrocarbons at that time <br /> .Ljyd�A'bon Oil and Grease <br /> Hydrocarbon oil and grease were below detection limits in all three wells <br /> Organochlorine Pesticidgs and PC�� <br /> Pesticides and PCBs were below detection limits in all throve wells <br /> 5.0 CONCLUSIONS <br /> Our findings and conclusions are as follows <br /> • Benzene was not detected in any of the soil or water samples <br /> • Pesticides and PCBs were below detection limits to all three wells <br /> • Low levels of petroleum products were detected in soil in MW-3 The <br /> maximums of these levels were <br /> - Total petroleum hydrocarbons (TPH) as gasoline 68 parts per million (ppm) <br /> - Toluene 50 parts per bdhon (ppb) <br /> - Xylenes 730 ppb <br /> - Ethylbenzene 350 ppb <br /> The groundwater in MW-3 is at 8 39 Leet below ground surt,we and the <br /> affected soil is located less than 5 feet from the groundwater Due largelj to <br /> the shallow groundwater, Category 3 of the Leaking Underground Fuel Tank <br /> (LOFT) Field Manual would typically a ly Clayton will consult with the San <br /> joaqum County, Environmental Health Division, and with the Central Valley <br /> Regional Water Quahty Control Board (RWQCB) on the status of this site <br /> • The concentration of hydrocarbon oil and rrease was 250 ppm in a soil sample <br /> from MW-3 Tnere are no set action leveh for oil and grease, however, when <br /> concentrations exceed 100 ppin the RWQCB': Reco mendations for tli <br /> );v".u tion Lind Investigjjion of US Ts requires a Soil/gioundwater investig,moi7 <br /> This study satisfies the RWQCB requirements The 100 pprn level is not d <br /> cleanup level The cleanup level is determined by assessing the potential for <br /> soil contamination to impact groundwater <br /> • Hydrocarbon nil and grease were also detected in soil samples from MW I incl <br /> MW-2, but are within acceptalgle levels as determined by the RWQCB <br />