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_______ <br /> petroleum hydrocarbons as diesel (TPHI'; by EPA methods 8020/8015. <br /> The laboratory results showed low levels of BTEX and TPHD (Table <br /> 2) . The laboratory rp ort and chain-of-custody are presented in <br /> , <br /> Attachment 2. <br /> On May 22, 1990 all four monitoring wells at the site were <br /> developed by extracting four well volumes (casing plus <br /> sandpack) . Groundwater samples were collficted using a teflon <br /> bailer with a bottom emptying device. The water samples were <br /> contained, preserved and transported with a chain-of-custody to <br /> Sequoia Analytical, a state certified hazardous waste laboratory, <br /> in accordance with EPA protocol. The samples were analyzed for <br /> BTEX and TPHD by EPA method 8020/8015. <br /> The laboratory results for the May 22, 1990 groundwater sampling <br /> reported non-detectable levels of diesel hydrocarbons in wells <br /> MWI, MW2, and MW3 (Table 3). Result from MW4 reported 8 ppb <br /> benzene, 4 ppb toluene, 4.1 ppb ethylbenzene, 14 ppb xylenes and <br /> 1000 ppb total petroleum hydrocarbons as diesel (Table 3) . The <br /> benzene level is the only constituent that is above state action. <br /> levels. Laboratory report and chain--of-custody documentation are <br /> presented in Attachment 2. <br /> The non-detectable levels in the up and down gradient wells <br /> indicate that the diesel contamination is localized around the <br /> former tank pit. It is recommended that the quarterly <br /> monitoring/sampling program continue to ensure that the <br /> contamination does not migrate. i' <br /> If you have any questions regarding this project, please contact <br /> Bill Channell or myself at your convenience. <br /> Respectfully, <br /> WaterWork <br /> I <br /> Bill Channell <br /> Senior G olQgist <br /> Ruseoil W. Juncal. <br /> CA Registered Geologist No. 3864 <br /> JK/tp <br /> i <br /> 4 ;. <br />