Laserfiche WebLink
9 0 <br /> Scott Mansholt - 2 - 5 August 2003 <br /> ChevronTexaco <br /> Mountain House Site#3 <br /> The workplan-proposes the installation of at least seven borings and up to five additional "step out" <br /> borings to collect soil and groundwater samples for laboratory analysis to delineate the lateral and <br /> vertical extent of TPH near borings GP-96, GP 97, GP 117, GP 120, and GP 173. <br /> ChevronTexaco and Regional Board staff, to expedite the characterization process during the course of <br /> the investigation work, will review the results of analysis and field observations to determine the need <br /> for additional borings and sampling. <br /> Based on our review of our records and the workplan, we have the following comments: <br /> • Preliminary results that elevated concentrations of petroleum hydrocarbons are present in soil <br /> and free phase petroleum in groundwater warrant remediation upon completion of defining the <br /> lateral boundaries of the pollution; a remedial action plan and time schedule should be prepared <br /> and included with the report; and, <br /> • ChevronTexaco needs to perform a search and survey of all production wells used for <br /> municipal, domestic, agriculture, industrial, and other uses within 2,000 feet of the Mountain <br /> House properties. <br /> We concur with the workplan provided our comments described above are addressed. <br /> By 2 September 2003, please submit your plan and time schedule for conducting the scope of work <br /> described in the workplan and the additional activities outlined above. Please notify Regional Board <br /> staff at least 48 hours prior to commencing the field investigation and drilling activities. <br /> If you have any questions of comments, please contact Dean Hubbard at (559) 445-5179. <br /> SHELTON R. GR Y C. DEAN HUBBARD <br /> Senior Engineering Geologist Associate Engineering Geologist <br /> RG No. 5357 <br /> cc: Mr. Mike Infurna, San Joaquin County Public Health Services, Stockton <br /> Mr. Stan Ploof, Trimark Communities, Tracy <br /> Mr. Garrett Turner, SAIC, Oakland <br /> Mr. Gary Foote, Geomatrix, Oakland <br />