Laserfiche WebLink
PUBLIC I-IrEALTH SERVICES Pa <br /> :C1 <br /> SAN JOAQUIN COUNTY r' y <br /> ENVIRONMENTAL HEALTH DIVISION s <br /> Karen Furst, M.D., M.P.H., Health Officer <br /> 304 East Weber Avenue, Third Floor - Stockton, CA 95202 <br /> 2091468-3420 <br /> ALEX PEREZ OCT 131997 <br /> SHELL OIL COMPANY <br /> PO BOX 4023 <br /> CONCORD CA 94524 <br /> Re; Shell Service Station Site Code: 1660 <br /> 7910 Lower Sacramento Road <br /> Stockton CA 95209 <br /> San Joaquin County Public Health Services Environmental Health Division(PHS/EHD)has reviewed the Enviros <br /> "Quarterly Monitoring Report-Second Quarter 1997"dated August 4, 1997. PHS/EHD has prepared the <br /> following comments for your consideration and response. <br /> The quarterly report included the results of the June 10, 1997 sampling event. As PHS/EHD indicated in <br /> correspondence dated May 28, 1997,the work plan which was submitted in February 1996 to install two soil <br /> borings in the area of the northern dispenser island would be evaluated once the next groundwater sampling results <br /> were available. The June 1997 sample results did not appear to confirm the February 1997 sample results which <br /> documented methyl tertiary butyl ether concentrations in the groundwater of up to 800 ppb in monitoring well, <br /> MWL Low levels of volatile hydrocarbons were evidenced as well as methyl tertiary butyl ether of up to 17 ppb in <br /> MW3 in groundwater samples collected on June 10, 1997. Quarterly monitoring and sampling should continue. <br /> PHSIEHD had requested that the scope of work proposed in the February work plan be evaluated based on recent <br /> groundwater sample results. The quarterly report indicated that Enviros was prepared to implement the work plan. <br /> Please note that the work plan did not include analysis for methyl tertiary butyl ether or the other blending <br /> oxygenates which have been used by the petroleum industry and which will be required. Also, PHS/EHD believes <br /> that an additional soil boring in the area of the former tank is necessary to confirm that the remaining soil <br /> contamination is of a sufficiently small mass and will not impact groundwater quality. The detection of <br /> contaminants in the groundwater suggests that some leaching of soil contaminants may have occurred,particularly <br /> given the recent rise in the groundwater table of greater than 15 feet since the investigation was first initiated in <br /> 1989. <br /> Please submit a drilling permit application and the$89 fee for the proposed soil borings. Once the permit has been <br /> issued,please proceed with scheduling the field work with both PHS/EHD and the drilling contractor. Since the <br /> boreholes which result from geoprobe drilling are narrow,all boreholes will be destroyed using a tremmie pipe to <br /> place the neat cement grout from the bottom up. Once field activities have been completed you must contact <br /> PHS/EHD to discuss the selection of soil samples and the laboratory methods which will be used to analysis the <br /> samples. <br /> If you have any questions or wish to schedule field inspections, please contact me at(209)468-0337. <br /> Donna Heran,REHS,Director <br /> E�nvirnonmental Health Division <br /> ' I4 � <br /> Mary Meays, Senior REHS Margare Lagorio,REH <br /> Site Mitigation Unit Supervisor <br /> cc: Pat Anderson, Central Valley Regional Water Quality Control Board <br /> Diane Lundquest,Enviros <br /> A Division of San Joaquin County Health Care Services <br />