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I This interim action/pilot scale study of methods to enhance the zone of influence during injection and to accelerate abiotic dehalogenation is proposed for the French Camp site. This pilot study will consist of two actions: hydraulic fracturing of the intermediate zone and injection of zero- valent iron into the intermediate aquifer. Detailed information regarding fracturing methodology and the injection of zero-valent iron is ' provided to support the application for this proposed activity. This will provide an opportunity to assess delivery methods, effectiveness in the abiotic reduction of carbon tetrachloride and its degradation products, and the time period for reduction. The following information is included in the application. • A project description including: • stochiometry for target compounds, • identification of expected intermediate and end products, • justification for quantity of amendment proposed, ' • assumptions used, • timetable for implementation, • monitoring scope and schedule, ' • Background geochemistry, • Chemical characterization of amendment, • An assessment indicating that the applicant could extract breakdown products from the igroundwater test zone, if necessary, • A contingency plan that identifies a strategy to restore the affected portion of the aquifer to ' pre-project conditions, a downgradient point of compliance, and trigger value(s) of constituents to implement the contingency plan, • A site map showing location of the injection area in relation to the facility and referenced monitoring wells, and • Other features of the project that warrant discussion. 2. Proiect Description The proposed project focuses upon the intermediate zone (approximately 60 to 80 feet below ground surface (bgs)) at the French Camp Elevator. Groundwater samples from wells ' penetrating this zone have the highest reported concentrations of carbon tetrachloride. Hydraulic fracturing will create horizontal preferential zones for emplacing the treatment material. Granular iron filings are to be injected into these fractures to abiotically dehalogenate the carbon ' tetrachloride. In addition to three injection points, two monitoring wells will be added to evaluate the effectiveness of the injection process. Figure 2 depicts the layout of injection points and monitoring wells. RACONTGRAMCC14Cargil[Trench Camp\Waste Discharge Application\supp info 6-29-04.doc 3