Laserfiche WebLink
r <br /> CAMBRIA28 <br /> October 25, 1999 <br /> Mr Harlin Knoll <br /> San Joaquin County Environmental Health Division <br /> 304 East Weber Avenue, Third Floor <br /> Stockton, California 95201 <br /> Re Quarterly Monitoring Report - Third Quarter 1999 <br /> Shell-branded Service Station <br /> 4445 Pershing Avenue <br /> Stockton, California <br /> SAP Code 136142 <br /> Incident No 98996182 <br /> Dear Mr Knoll <br /> This report describes the recently completed activities associated with groundwater <br /> monitoring and sampling at the referenced site (Figures I and 2) This report was prepared to <br /> meet quarterly reporting requirements issued by the Regional Water Quality Control Board, <br /> Central Valley Region and San Joaquin County Public Health Services <br /> Quarterly Monitoring & Sampling Summary <br /> Groundwater monitoring and sampling for this quarter is summarized below <br /> • Blaine Tech Services, Inc (Blaine) of San Jose, California measured groundwater <br /> levels in wells MW-1 through MW-4, VEW-1, and VEW-2 and collected samples <br /> from wells MW-1 through MW-4, and VEW-1 on August 20, 1999 Well VEW-2 had <br /> insufficient water for sampling Samples were transported to Sequoia Analytical <br /> (Sequoia) of Morgan Hili, California for chemical analyses <br /> • Cambria Environmental Technology, Inc (Cambria) evaluated water-level <br /> measurement data and prepared a groundwater contour/chemical concentration map <br /> (Figure 2) Groundwater flow direction varies beneath the site, flowing north, <br /> Oakland CA northeast, and south from a hydraulic ridge located around wells MW-2 and MW-4 <br /> Son o m a CA The hydraulic gradient ranges from 0 003 to 0 010 <br /> Portland OR <br /> Seattle WA <br /> • TPPH was not detected in any of the wells sampled Benzene was detected only in <br /> Cambna well MW-2 at a concentration of 0 621 ppb MTBE was not detected in any of the <br /> Environmental <br /> Technology,Inc <br /> wells <br /> oelkins Street <br /> P O BOX 259 <br /> Sonoma CA 95476 <br /> Tel(7o7)935-4850 <br /> Fax(707)935-6649 <br />