Laserfiche WebLink
Alf i o1'1r <br /> chevron <br /> m Chevron <br /> r.P w/ <br /> Chevron Products Company <br /> 6001 Bollinger Canyon Road <br /> April 28, 1997 Building L <br /> San Ramon,CA 94583 <br /> P.0.Box 6004 <br /> San Ramon,CA 94583-0904 <br /> Ms.Mary Meays Marketing—Sales West <br /> San Joaquin County Environmental Health Phone 510 842-9500 <br /> 304 E. Weber Ave., Third Floor <br /> Stockton, CA 95202 <br /> Re: . Chevron Station#9-0557 139-South Center Street Stockton CA <br /> Attached groundwater monitoring report(Blaine Tech, 3/20/97) <br /> ti <br /> Dear Ms. Meays: <br /> Please find attached a report dated March 20, 1997,which was prepared by Chevron's consultant,Blaine <br /> Tech Services Inc. (Blaine Tech), to describe the results of groundwater monitoring that was performed <br /> the subject site on February 27, 1997. <br /> In February,Blaine Tech gauged and sampled all seven site-related wells. The measured groundwater <br /> elevations mere the highest ever measured beneath the,subject site..The measured direction of <br /> groundwater flow was toward the southeast. All groundwater samples were analyzed for the presence of <br /> TPHGas,BTEX constituents, and MTBE. In addition, all seven wells were sampled for various <br /> parameters relating to the evaluation of intrinsic bioremediation potential. The measured concentrations <br /> of TPHGas at wells MW-2 and MW-5 were greater than those previously detected. The results obtained <br /> from these two wells during the next sampling event will be evaluated to confirm the occurrence of any <br /> increasing trends. <br /> I would also like to take this opportunity to respond.to your letter dated April 7, 1997 in which, several <br /> issues were raised including perceived deficiencies in Pacific Environmental Group's Work Plan <br /> Addendum dated October 10, 1996. My response to these issues(boldfaced below)are as follows: <br /> The work plan and addendum failed to include any evaluation of remedial alternatives. <br /> Chevron believes that it is premature to begin considering the feasibility of remedial alternatives. The <br /> initial response actions taken to date by Chevron appear to be appropriate based on the potential threat to <br /> human and environmental health caused by the release of motor fuels beneath the subject site. The <br /> evaluation and selection of remedial alternatives will be performed as soon as the associated levels of <br /> human and environmental health risk are characterized. <br /> Sufficient information has been obtained thus far, about contaminants of concern and sources(primary <br /> and secondary)at the subject site. At this time,less information is known about transport mechanisms, <br /> exposure pathways, and sensitive receptors. The work plan by Pacific(9/26/96)proposed a monitoring <br /> well to define the downgradient extent of contaminant flow, a survey to identify sensitive receptors in the <br /> vicinity of the subject site, and research to understand other potential sources of groundwater <br /> contamination in the site vicinity. The work proposed in that work pian focuses on investigating <br /> subsurface transport mechanisms, identifying associated exposure pathways, and characterizing sensitive <br />