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Rantec Work Plan for Amended Bioremediation Pilot Study BP Terminal 40T November 10, 2008 to a maximum depth of 20 ft bgs. A traffic rated well box will be installed to grade. After the wells are installed, they will be developed using surge block agitation. Injection Program The existing injection system described above will be used for this pilot study. The injection solution will be prepared by mixing calcium sulfate with potable water. The solution will be injected into each well via an above ground conveyance pipeline at a rate of 0.074 gpm. The solution injection rate and total quantity of solution injected will be controlled by a valve and monitored by a digital flow meter located at the main injection system. The initial aqueous sulfate solution will consist of 250 milligrams per liter (mg/L) sulfate, prepared by diluting a saturated solution of calcium sulfate (470 mg/L sulfate). The sulfate concentration will be increased once the treatment has been demonstrated to work as proposed and not cause exceedances of sulfate outside of the treatment area. The flow rate of 0.074 gpm correlates to approximately 106 gallons of solution per day. Each injection well will initially receive approximately 100 gallons of 250 mg/L sulfate solution per week. The annual estimated mass is 1.3 kg of sulfate per year per injection point. Once sulfate has been demonstrated to reduce to sulfide, the dosing rate will be increased to 300 gallons per week or an annual sulfate dose of 3.9 kg of sulfate per year. That correlates to a petroleum mass reported as toluene of approximately 1 kg per injection well annually. Assuming a radius of influence of 10 feet a saturated thickness of 10 feet and a uniform hydrocarbon concentration of 50,000 pg/L that correlates to a total mass of hydrocarbons of 1.4 kg or approximately the treatment mass of the proposed injection volume annually. Monitoring Program Groundwater samples will be collected from nine downgradient monitoring wells: AR/MW-1A, AR/MW-5A, AR/MW-5B, AR/MW-5C, AR/MW-50, AR/MW-6AR, AR/MW-10A, AR/MW-11A, and AR/MW-12A and one upgradient monitoring well, PS/P29. Groundwater from these wells will be analyzed for dissolved oxygen (DO), oxidation/reduction potential (ORP), ferrous iron (Fe II), pH, conductivity, and temperature in the field. Analytical samples will be collected for gasoline range organics (GRO), benzene, toluene, ethylbenzene, xylenes (collectively BTEX), and fuel oxygenates. In addition, groundwater samples will be analyzed for total alkalinity, nitrate-nitrogen, sulfate, and sulfide. Samples will be collected weekly during the first month of chemical injections and then monthly during the first six months, and quarterly for the remainder of the one-year pilot test. The monitoring program will be modified, as necessary, depending on results of the bio-parameter analyses in the treatment area and downgradient monitoring wells. Calcium, sulfate, total dissolved solid concentrations, and the tracer compound will be monitored at downgradient monitoring well AR/MW-1A. If concentrations of sulfate are below the background levels and the tracer compound is detected at the downgradient monitoring well, another three month injection period will be conducted with double the concentrations of sulfate. This three month cycle of increased concentrations will continue until the end of the pilot test. This would indicate that the tracer is reaching the downgradient monitoring point; however, the concentrations of sulfate were insufficient for the microbes to treat all of the hydrocarbons. Samples will be collected weekly following the first month of increase in concentrations and then monthly until the end of the three month period. 40T Work Plan for Amended Bioremediation Pilot Study.doc 7