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Mr. Bill Duckenfield 2 7 October 1991 The Quarterly Monitoring Summary (QMS) did not state whether the nitrate reported was as NO3 or N. This distinction is important since the Primary Drinking Water Maximum Contaminant Level (Primary MCL) for nitrate as NO3 is 45 mg/l and nitrate as nitrogen is 10 mg/l . It is apparent that the A zones definitely contain nitrates above the Primary MCL, while the B and C zones may be above the Primary MCL. Also, HLA should plot salt (EC or TDS) contours, since EC and TDS are the major constituents of concern. The water level contours show that a ground water depression exists around MW1 and the extraction wells, but no discussion is made as to whether or not the extraction wells are containing the salt plume and pulling the contaminated water back in to be treated. The extraction well zone of influence should be plotted on a base map that also shows the salt plume so that it can be determined if the corrective action program is effective. No discussion was made about why the water level elevation contours for the B zone show there are cones of depression for some months and not for others. Likewise, the contours in the B zone varied significantly and the report did not discuss the causes for these variations. The contours indicate that the extraction wells have very little effect on the ground water levels or flow direction in the C zone. On page 6, the QMS states that the existing monitoring well network does not encompass the entire TDS impacted ground water plume, and the TDS levels appear to be increasing in the B and C zones. While we concur with the recommendation for continued monitoring in the impacted areas, the report does not discuss the reasons the ground water extraction system is not working in the B and C zones. The QMS also states that quarterly monitoring of ground water elevations should be adequate provided there is no substantial change in the ground water extraction system. Reducing the extraction rate due to problems with the injection well system is a substantial change in the operations of the ground water extraction system. Therefore, we will continue to require monthly measurement of ground water elevations; however, a reduction in the number of wells measured could be accomodated, if sufficiently justified. In the 15 January 1990 HLA report, HLA recommended against additional extraction wells because the ground water extraction system appeared to be influencing the direction of the ground water flow towards the recovery well . The 1990 report also stated that the further monitoring would provide information on the capture zone development, the northern limits of the plume, and the effectiveness of the ground water extraction system. It was our understanding that these issues would be addressed in the 28 August 1991 report. We request Victor Fine Foods submit a Technical Report to the Regional Board by 16 November 1991 . The report must address the following issues: 1 . Identify which wells may be eliminated from the monitoring program and why.