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Comment 5: "Waste Discharge Requirements appear necessary for this remediation proposal due to the lack of hydraulic control, discharge of hydrocarbons above those listed in the General Waste Discharge Requirements for Petroleum Discharges to Land, and the proposal to discharge nitrogen and phosphorus as necessary. A Report of Waste Discharge must be submitted'to Ms. Christine Holm, of this office" Response 5: The UVB system does not create any waste water for discharge to the surface. Groundwater extracted through the lower screen of the UVB well is reinjected through the upper screen of the UVB well within the same zone, after volatile and semivolatile constituents have been removed in the air stripper located within the well, between the two screens. No discharge permits were required in previous UVB system applications in California. A memorandum was faxed to Ms. Christine Holm on 8 October 1996 by EA Engineering notifying her of the impending UVB system installation and describing the proposed system. In subsequent telephone conversation with Dr. Kyriacou of EA Engineering, Ms. Christine Holm indicated that based on her understanding of the UVB system, a discharge permit would not be required because of extraction and reinjection within the same zone. Comment 6: "This proposal is not intended to treat the entire contaminant plume and a significant portion will not be affected by the UVB well" Response 6: Comment noted. The intent of the present action is to remediate the on-site plume and to control further migration. The part of the downgradient plume beyond the boundaries of the UVB circulation cell will be addressed at a later time. The installation of the UVB well at the location of former monitoring well RW-3 was deemed the most effective placement location, because it is situated within the site and near the center of the plume. Comment 7: "According to the case studies, ground water contamination concentrations may increase after startup of the UVB well due to mobilization of contaminants from the pore spaces,presumably due to the flushing effect of the water circulation." Response 7: An initial increase in ground water contamination concentrations within the circulation cell after startup of the UVB well due to mobilization of contaminants from the pore spaces is expected and would be indicative of the successful establishment of a circulation cell around the UVB well. Contaminant concentrations within the circulation cell are expected to follow a steady decline after an increase and fluctuation in the initial startup period.