Laserfiche WebLink
*ENVIRONMENTAL HEALTH DEPARTMENT <br /> SAN JOAQUIN COUNTY <br /> Unit Supervisors <br /> Z Donna K.Heran,R.E.H.S. <br /> 304 East Weber Avenue, Third Floor carr Bergman,R.E.H.S. <br /> Director Mike Huggins,R.E.H.S.,R.D.I. <br /> Al Olsen,R.E.H.S. Stockton, California 95202-2708 Douglas W.Wilson,R.E.H.S. <br /> cq.. Program Manager Telephone: (209) 468-3420 Margaret Lagorio,R.E.H.S. <br /> Laurie A.Cotulla,R.E.H.S. Robert McClellon,R.E.H.S. <br /> Program Manager Fax: (209) 464-0138 <br /> Mark Barcellos,R.E.H.S. <br /> KAREN PETRYNA MAY O 32004 <br /> SHELL OIL PRODUCTS US <br /> 20945 S WILMINGTON AVE <br /> CARSON CA 90810 <br /> RE: Shell Station SITE CODE: 1223 <br /> 6131 Pacific Ave <br /> Stockton CA 95207 <br /> San Joaquin County Environmental Health Department(SJC/EHD) has reviewed "Site <br /> Investigation/First Quarter 2004 Groundwater Monitoring Report"dated April 9, 2004 that was <br /> submitted on your behalf by Cambria Environmental Technology, Inc. (Cambria) and has the <br /> following comments. <br /> In February 2004, two additional monitoring wells were installed as part of the investigation of <br /> the above-referenced contaminated underground storage tank(UST)site. MW-12 is a shallow <br /> well, installed offsite and down gradient to the groundwater flow direction; MW-13 is a deep, <br /> discretely screened well, installed onsite. Both wells had detections of petroleum hydrocarbon <br /> contamination in the groundwater at the reported monitoring and sampling event. Further <br /> sampling and analysis will establish the contaminant trends in these points. <br /> Cambria has again requested, on your behalf, discontinuing sampling of monitoring wells MW-6, <br /> MW-7 and MW-9 through MW-11. SJC/EHD does not approve this request. Monitoring wells <br /> MW-6 and MW-7 have historical trends of total petroleum hydrocarbons as gasoline(TPHg)and <br /> BTEX (benzene, toluene, ethylbenzene and xylenes), and quarterly groundwater monitoring and <br /> sampling of them must continue until directed otherwise by this agency. Monitoring wells MW-8 <br /> and MW-9 both have had detections of benzene above the reporting limit in five of seven <br /> sampling events. Citing these detections of benzene, Cambria proposes to continue quarterly <br /> sampling of MW-8. SJC/EHD will approve modifying the sampling regime at this site to semi- <br /> annual monitoring of MW-9, and annual sampling of MWA0 and MW-11. <br /> Following review of'Third Quarter 2003 Groundwater Monitoring Report"and the submitted <br /> chromatograms of the water analyses, SJC/EHD concurred, in correspondence dated <br /> December 23, 2003,that the TPH concentrations in wells MW-6 through MW-11 appear to <br /> actually be tetrachloroethane (PCE). However, these wells also represent the non-detect line of <br /> the plume emanating from your site, and provide useful.information as such. If you have any <br /> questions please call Lori Duncan at (209)468-0337. <br /> Donna Heran, REHS, Director <br /> Environmental Health Department p \ <br /> Lori Duncan, Senior REHS Nuel C. Henderson, Jr., RG <br /> LOP/Site Mitigation Unit IV LOP/Site Mitigation Unit IV <br /> cc: James Barton, CVRWQCB <br /> Joe Neely, Cambria <br />