Laserfiche WebLink
d - - <br /> San Joaquin County <br /> Environmental Health Department DIRECTOR <br /> z ' 02 <br /> Donna Heron, REHS <br /> 600 East Main Street <br /> -� PROGRAM COORDINATORS <br /> < Stockton , California 95202m3029 Robert McClellan, REHS <br /> Jeff Darruesco, REHS, RDI <br /> c Website: www.sjgov. org/ehd Kasey Foley, REHS <br /> 9tiF °a�' - Phone : (209) 468-3420 <br /> Fax: (209) 464-0138 <br /> August 3, 2010 <br /> Mr. Denis L. Brown Mr. David Hoover <br /> Shell Oil Products US California Fuel Supply Inc <br /> HSEQ / Science & Engineering 587 Ygnacio Valley Road <br /> 20945 S. Wilmington Ave . Walnut Creek , CA 94596 <br /> Carson , CA 90810 <br /> Subject: Former Shell Station LOP Case #: 390870 <br /> 2575 Country Club Blvd . APN : 123-020- 12 <br /> Stockton , CA 95204 Global ID#: T0607732095 <br /> The San Joaquin County Environmental Health Department (EHD) has reviewed Bench <br /> Scale Test Report Addendum by Conestoga-Rovers & Associates (CRA) dated June 11 , <br /> 2010. The EHD had directed Shell in correspondence dated April 21 , 2010, to submit an <br /> addendum that addressed concerns related to the original Bench Scale Test Report. <br /> Conclusions in the addendum stated that persulfate leached general metals from the soil , <br /> thereby exceeding their respective water quality objectives (WQOs), with chromium <br /> presenting the greatest concern . CRA further provided that the chromium results <br /> "represents an extreme worst case scenario since the oxidant concentration in the <br /> (leachate) test was significantly higher than would be encountered in the field. " CRA <br /> concluded that chromium leached by the oxidant injection "reprecipitated" in the injection <br /> area 24-52 weeks after the final injection . Although only chromium was statistically <br /> analyzed in the study CRA referenced in the addendum , it was concluded by CRA that the <br /> other leached metals "were expected to behave similarly". <br /> In addition to concerns with chromium impacting groundwater and possible reprecipitation <br /> to pre-injection concentrations, the EHD is concerned with the sodium (Na) concentrations <br /> reported in the bench scale test. Na concentrations in untreated groundwater samples <br /> exceeded WQOs. To be sure that the Na concentrations reported are accurate, the EHD <br /> recommends that additional groundwater background samples be collected offsite from <br /> monitoring wells for analysis of Na. Other underground storage tank (UST) sites are <br /> located very close to this former Shell site and you should make contact with the owners <br /> of these sites to access some of their monitoring wells for Na sample collection and <br /> analyses . The EHD will try to assist with facilitating access to these sites if needed . <br /> Mr. James Barton of the CVRWQCB advised the EHD that background Na concentrations <br /> that exceed WQOs disqualify a site from receiving a general permit for waste discharge <br /> requirements. A site specific permit is required for such sites. In addition to the significant <br /> costs associated with a site specific waste discharge requirement MDR) permit, Mr. <br /> Barton also advised that much more time is needed to process the application . It can be <br /> more than six months before a determination can be made if the permit can be issued . <br />