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WASTE DISCHARGE REQUI*NTS ORDER NO.R5-2003-0166 • 2 CONTIGROUP COMPANIES FRENCH CAMP GRAIN ELEVATOR ENHANCED BIOREMEDIATION PILOT STUDY SAN JOAQUIN COUNTY zone upgradient from monitoring well MW-3B, as shown on Attachment B, which is attached hereto and made part of this Order by reference. 6. The Discharger will inject four pounds of HRC®per linear foot of vertical depth in the water bearing zone. Regenesis, the manufacturer of HRC®,provides software to determine the dosing volume. Four pounds of HRC®per linear foot is the minimum dosage rate recommended by Regenesis. 7. The Discharger will collect baseline groundwater samples a minimum of two weeks prior to the injection of HRC® and will conduct routine monitoring of the new well and existing monitoring well MW-4B for volatile organic compounds, lactic acid, metals, and general chemistry parameters, as required in the attached MRP No. R5-2003-0166. The estimated groundwater flow velocity is 10 feet per year. The new well will be installed about eight feet downgradient of the pilot study treatment zone. The HRC®is estimated to radiate out about five feet. Based on this, the Discharger estimates that within four months the HRC® will reach the newly installed well. 8. Bench-scale testing was not performed because the most common mechanism of degradation of chlorinated compounds is reductive dechlorination where the chlorinated compounds serve as electron acceptors and carbon is the main electron donor. Injecting HRC® will stimulate growth of indigenous microorganisms by providing a carbon substrate, therefore accelerating the reductive dechlorination process. The Discharger has determined that HRC®injections will reduce pollutant concentrations because monitoring data has shown that reductive dechlorination is occurring under anaerobic conditions and carbon tetrachloride is breaking down. 9. Byproducts from the injection of HRC®may include carbon dioxide, reduced forms of sulfate such as hydrogen sulfide, and breakdown products of carbon tetrachloride, such as chloroform,methylene chloride (dichloromethane), chloromethane and chloride ion. With the exception of chloride ion, the breakdown products of carbon tetrachloride are expected to be intermediate compounds. The Discharger will monitor for these byproducts, along with the constituents listed in Finding 7, in accordance with the attached MRP No. R5- 2003-0166. 10. In the event that lactic acid reaches monitoring well MW-413 above baseline concentrations during the pilot study, the Discharger will implement a pump and treat system. The Discharger will install up to 10 extraction wells screened in the B water bearing zone. Recovered water will be temporarily stored on site pending transport to the Stockton Regional Wastewater Control Facility. Recovered water will be treated using granular activated carbon and/or air stripping only if an applicable groundwater parameter concentration exceeds the concentration limit allowed by the Wastewater Control Facility. The Discharger may also submit a Report of Waste Discharge to reinject the treated water if initial results show that groundwater extraction may be a long term corrective measure.