Laserfiche WebLink
Metadata
Document management portal powered by Laserfiche WebLink 9 © 1998-2015 Laserfiche. All rights reserved.
Cvv <br /> 1117 Lone Palm Avenue, Suite B <br /> Modesto, CA 95351 <br /> www atc-enviro com <br /> ATC209 579 2221 <br /> Fax 209 579 2225 <br /> A S S O C I A T E $ I N C <br /> July 8, 2004 <br /> 54 62583 0001 JUL 0 9 2004 <br /> ENVIRONMENT HEALTH <br /> PERMIT/SERVICES <br /> Ms Mary Serra <br /> Regional Water Quality <br /> Control Board <br /> 11020 Sun Center Drive#200 <br /> Rancho Cordova, CA 95670-6114 <br /> Subject Revised Workplan for a Bench Scale Treatability Study for Reducing Hexavalent <br /> Chromium at Diamond Walnut Growers, 1050 South Diamond Street, Stockton, <br /> California <br /> Dear Ms Serra <br /> ATC Associates Inc (ATC) has prepared this revised workplan, on behalf of Diamond Walnut <br /> Growers (DWG), for conducting a bench scale treatability study to evaluate two methods of reducing <br /> hexavalent chromium (CrVI) in situ in groundwater and soil at the above referenced site Submittal of <br /> work plan for a bench scale treatability study was requested by the California Regional Water Quality <br /> Control Board (CRWQCB) in correspondence dated July 29, 2003 ATC submitted the Workplan for <br /> a Bench Scale Treatability Study for Reducing Hexavalent Chromium, dated October 31, 2003, to the <br /> CRWQCB The CRWQCB issued comments to the work plan in a letter dated December 18, 2003, <br /> and a meeting with CRWQCB staff, DWG, and ATC personnel was held at the site on February 3, <br /> 2004 In correspondence dated June 10, 2004, the CRWQCB requested subrruttal of a revised <br /> workplan <br /> The purpose of the bench scale treatability study is to evaluate the potential effectiveness of remedial <br /> options under laboratory conditions prior to implementation in the field The scope of work includes <br /> collecting soil and groundwater samples from the site, conducting laboratory testing of the soil and <br /> groundwater media to evaluate the potential of ferrous iron solution and calcium polysulfide to reduce <br /> and stabilize CrVI via mjection into the subsurface, and preparation of a summary report The <br /> proposed scope of work is described in detail in the following paragraphs <br /> BACKGROUND INFORMATION <br /> The DWG plant is located northeast of the intersection of Charter Way and South Diamond Street in <br /> Stockton, California (Figure 1) According to DWG, the facility has been operating as a walnut <br /> processing plant since the 1950s Five underground concrete vaults were located north and east of the <br /> main processing building and formerly contained refrigerants used in the plant cooling systems (Figure <br /> 2) Vaults 1, 5, and 6, installed between 1974 and 1976, were concrete and historically contained <br /> propylene glycol Vaults 1 and 5 had 1,200-gallon capacities and Vault 6 had a 500-gallon capacity <br /> s�envuronmenta11625831reports\RevlsedWKP-Bench test doc 1 <br /> ENVIRONMENTAL, GEOTECHNICAL AND MATERIALS PROFESSIONALS <br /> I <br />