Laserfiche WebLink
Lee Higgins - 9 - 7 December 2010 <br /> Chevron, TAOC Tracy Rail Yard <br /> petroleum hydrocarbons detected are consistent with severely biodegraded San <br /> Joaquin Valley crude oil and possibly bunker fuel. <br /> • Additional groundwater delineation is needed onsite north and northeast of boring <br /> TRY-29 to address areas of gaps in the data and to evaluate the downgradient extent <br /> of affected groundwater within the central area of OU-5. <br /> • The analytical results for soil vapor samples from the five different affected areas of the <br /> Site were ND for benzene and naphthalene. Analysis for toluene, ethylbenzene, and <br /> xylenes reported low concentrations present, none of which exceeded respective <br /> environmental screening levels for a residential or commercial risk exposure scenario. <br /> • The offsite extent of crude oil affected soil and/or groundwater will be addressed in <br /> future investigations. Offsite areas located in adjacent residential properties needing <br /> further delineation include to the east and south of OU-2; south of OU-3; south and <br /> west of OU-5 and to the northwest of OU-5. Currently, AMEC is preparing a workplan <br /> to investigate offsite groundwater. <br />