Laserfiche WebLink
e <br /> PUBLIC, HEALTH SEkOVICES <br /> SAN JOAQUIN COUNTY a ?j <br /> ENVIRONMENTAL HEALTH DIVISION <br /> Karen Furst, M.D., M.I'.H., Health Officer <br /> iii 6" <br /> 304 East Weber Avenue, Third Floor • Stockton, CA 95202 <br /> 209/468-3420 JAN 0 2 2Q02 <br /> DONALD F. RODGERS JUNIUS MCKELVEY <br /> 11900 S UNION ROAD 515 W CHARTER WAY <br /> MANTECA CA 95336 STOCKTON CA 95206 <br /> RE: The Transmission Shop <br /> 515 W. Charter Way <br /> Stockton CA 95206 <br /> San Joaquin County Environmental Health Department (SJC/EHD) has reviewed the <br /> "Third Quarter 2001 Status Report for The Transmission Shop" dated October 25, 2001 <br /> that was submitted by IT Corporation (IT) on your behalf, as well as historical site <br /> investigative data, and has the following comments. <br /> Review of the historical investigative data submitted for this site indicates that the <br /> vertical and lateral extent of the petroleum hydrocarbon contamination present in soil <br /> has never been defined. The deepest soil samples analyzed were from 40.5-feet below <br /> surface grade (bsg) in borings 131 R and 132R. The sample from boring 132R, which was <br /> located on the south side of one of the former underground storage tanks, was reported <br /> to contain 1,500 milligrams per kilogram (mg/kg) of total petroleum hydrocarbons as <br /> gasoline (TPHg), 5.4 mg/kg of benzene, 32 mg/kg toluene, 14 mg/kg ethyl-benzene, 62 <br /> mg/kg total xylenes and 18 mg/kg methyl tertiary butyl ether (MtBE). The only boring <br /> which reported no detectable concentrations of contaminants in soil was boring 136R, <br /> which is located potentially up gradient to the source area at this site. <br /> Only one monitoring well, MW-1, has been installed at this site. This well was built to a <br /> total depth of 52.5 feet bsg, and has always reported significant amounts of TPHg and <br /> BTEX contamination. One single and three dual completed soil vapor extraction wells <br /> (VW) have also been installed at this site. Routine monitoring and sampling of two of <br /> these wells, VW-2 and VW-3, began during the second quarter of 2001. However, the <br /> report does not indicate whether the shallow or deep screened casing in each well is the <br /> one sampled. Analytical results from both of these wells have reported high quantities of <br /> contaminants, with up to 41,000 micrograms per liter(µg/I)TPHg, 5,600 µg/I benzene <br /> and 280 µg/I MtBE in SVE-2. Results from the groundwater monitoring and sampling <br /> events that have been conducted at this site to date indicate that the vertical and lateral <br /> extent of the dissolved contaminant plume has not been defined. <br /> In February 2000, operation of a soil vapor extraction remediation system began at this <br /> site. The status report indicates that all VW's except VW-4 are currently being used in <br /> conjunction with the remediation system. Current depth to groundwater at this site is <br /> approximately 21-feet bsg; therefore, the screen intervals of the deeper wells are <br /> submerged and not available for use in soil remediation. Analytical results of the influent <br /> air samples collected from the SVE system indicate that the concentrations of TPHg <br /> A Division of San Joaquin County Health Care Services <br />