Laserfiche WebLink
1 <br />PUBLIC ALTH <br />SAN JOAQUIN COUNTY <br />ENVIRONMENTAL HEALTH DIVISION <br />Karen Furst, M.D., M.P.H., Health Officer <br />304 East Weber Avenue, Third Floor • Stockton, CA 95202 <br />209/468-3420 <br />BRETT HUNTER NOV 2 11997 <br />CHEVRON USA INC <br />P O BOX 6004 <br />SAN RAMON CA 94583-0904 <br />RE: Chevron Service Station #9-6171 SITE CODE: 1784 <br />6633 Pacific Ave <br />Stockton CA <br />San Joaquin County Public Health Services, Environmental Health Division (PHS/EHD) has briefly <br />reviewed the "Work Plan for Waste Oil Tank, Hoist, and Product Line Removal" which was dated <br />November 4, 1997 and prepared by Pacific Environmental. PHS/EHD has the following comments <br />for your response. <br />The work plan submitted indicated that samples were going to be collected related to the removal of <br />an underground storage tank, a service hoist and gasoline product lines. The work plan also <br />suggested that if petroleum saturated soils were encountered that some limited excavation may be <br />performed. <br />Please note that the work plan failed to identify the soil contamination evidenced in the area of the <br />dispenser, in the sample collected by Pacific Environmental on September 22, 1995. Soil boring, B3 <br />evidenced 56 ppm TPH-gasoline at 2 feet below ground surface (bgs). This boring could not be <br />advanced to greater depths due to auger refusal, "by something metallic in nature", presumably <br />abandoned product piping. <br />The work plan is not consistent with the closure plan which was submitted to PHS/EHD staff, <br />Michael Kith, which stated that Touchstone would be collecting soil samples. Please provide <br />clarification regarding the designation of the company responsible for sampling. <br />The work plan also indicated that a selected sample would undergo EPA Method 8260 analysis. <br />Please note that Chevron has used an oxygenate other than methyl tertiary butyl ether (MTBE), <br />specifically Tertiary Amyl Methyl Ether (TAME). All soil samples collected from beneath the product <br />lines shall undergo EPA Method 8260 analysis. <br />Finally, there is concern regarding the definition of saturation of petroleum hydrocarbons and the <br />ability of soils contaminated with less than saturation concentrations to impact groundwater. Please <br />provide clarifications regarding the intent of Chevron to remediate petroleum hydrocarbon <br />contamination, prior to replacing the piping. Considerable expense has already been expended <br />attempting to investigate the dispenser island without interfering with the operation of the existing <br />piping. If piping is replaced in areas of contamination, it may interfere with the ability to access <br />these areas to determine the vertical and horizontal extent of any contamination evidenced. <br />Should Chevron wish to perform interim remediation, a more detailed plan will be required which <br />describes the maximum cubic yards which will be excavated and the sampling frequency to <br />A Division of San Joaquin County Health Care Services <br />