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• • TENTATIVE <br /> INFORMATION SHEET 2 <br /> WASTE DISCHARGE REQUIRMENTS ORDER NO.R5-2003-0030 <br /> SPX CORPORATION,MARLEY COOLING TOWER COMPANY <br /> IN SITU GROUNDWATER REMEDIATION PILOT STUDY,SAN JOAQUIN COUNTY <br /> chromium in the aquifer and to precipitate it out of solution,thereby immobilizing chromium. <br /> The ethanol is proposed as a carbon source to stimulate microbial growth and maintain reducing <br /> conditions to precipitate chromium out of solution. The pilot study will be conducted in two <br /> phases. <br /> The purpose of the Phase 1 pilot study is to demonstrate that injecting calcium polysulfide into . <br /> groundwater will effectively reduce hexavalent chromium to trivalent chromium, and to assess <br /> the radius of influence of a single injection of calcium polysulfide. The purpose of the Phase 2 <br /> pilot study is to demonstrate the effectiveness of the multiple-injection remediation approach <br /> and the persistence of reducing conditions in the shallow groundwater plume zone. <br /> During the Phase 1 pilot study,the Discharger proposes to inject up to 5,000 gallons of 3 percent <br /> calcium polysulfide solution and 50 gallons of ethanol into injection boring INJ-1 from 60 to 80 <br /> bgs over a period of two days. In addition to the calcium polysulfide and ethanol, sodium bromide <br /> (NaBr),a non-toxic,inorganic tracer will be included in the solution at a concentration of 200 <br /> milligrams/liter(mg/1). This tracer will help to demonstrate that the observed reductions in <br /> hexavalent chromium concentrations are due to chemical reduction rather than dilution by the <br /> injected solution. Temporary wells including an injection well and six monitoring wells will be <br /> installed to supplement the existing monitoring well network. <br /> Groundwater will be monitored for hexavalent chromium(Cr VI),total Cr,bromide(Br), copper <br /> (Cu), arsenic (As),iron(Fe),manganese(Mn),sulfate(SO4),nitrate(NOA Total Dissolved Solids <br /> (TDS) and general minerals by laboratory analysis. The oxidation/reduction potential(ORP)will <br /> be measured in the field along with dissolved oxygen(DO),electrical conductance(EC), <br /> temperature, and pH. Monitoring will begin prior to the calcium polysulfide/ethanol injection, and <br /> will continue at periodic intervals until it is no longer deemed necessary. <br /> During the Phase 2 pilot study, the Discharger proposes to install up to 75 direct injection <br /> points into 1 to 4 different treatment zones based on the results obtained from Phase 1 study. <br /> The injection points are intended to encompass the width of the shallow chromium <br /> groundwater plume upgradient of the highest hexavalent chromium concentration areas. At <br /> each injection paint, approximately 5,000 gallons of 3 percent calcium polysulfide solution <br /> with 50 gallons of ethanol and 200 milligrams per liter(mg/1)NaBr solution will be injected; <br /> injection volumes may be modified based on the results of the Phase 1 pilot test. The <br /> monitoring program will utilize the existing monitoring well network. Three temporary wells will <br /> be installed to supplement the existing monitoring well network. Groundwater will be monitored <br /> for the same suite of constituents as in Phase 1 pilot study. <br /> The Water Quality Control Plan for the California Regional Water Quality Control Board Central <br /> Valley Region, Fourth Edition (Basin Plan), designates beneficial uses, establishes water quality <br /> objectives, and contains implementation plans and policies for all waters of the Basin. he <br /> beneficial uses the groundwater at the site are municipal and domestic supply, industrial service <br /> supply, industrial process supply, and agricultural supply. <br />