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Letter to Larry Perino 2 October 18, 1993 <br /> program undertaken in drainages surrounding the Sunnyside Mine <br /> this summer. SGC has requested that Poughkeepsie Gulch be <br /> dropped from the area of the study, and has further requested <br /> that the requirement to collect four quarters of inventory <br /> data be reconsidered. Both of these requests appear to be <br /> well founded, however, the Division will withhold a <br /> determination on both items until staff has had an opportunity <br /> to review the initial water survey inventory report. <br /> 4 . SGC has proposed a water sampling program designed to detect <br /> water that has passed through the Sunnyside Mine workings and <br /> has subsequently made its way to the surface. The Division's <br /> opinion is that detection of emergent mine pool water is <br /> extremely important to assess the degree of success of the <br /> bulkhead program, and agrees that the program presented by SGC <br /> is the best way to detect such water. However, the Division <br /> believes that the tracer program is only one component of the <br /> data necessary to evaluate the affects of flooding the <br /> Sunnyside Mine. In addition to the monitoring program <br /> proposed by SGC, the Division will require that the evaluation <br /> of drainages surrounding the mine, colloquially referred to as <br /> the seep study, be continued. SGC will be required to collect <br /> field water quality parameters (pH, temperature, and <br /> electrical conductivity) and measure flows at all seeps, <br /> springs, and portals identified during the 1993 study, as well <br /> as at any new flows that may appear. Also, laboratory <br /> analysis of 20 percent of the stations should be conducted <br /> each year (the parameters suggested by SGC are acceptable) , <br /> such that analysis of all stations will be completed in 5 <br /> years. Laboratory samples should be from a variety of <br /> drainages each season. The seep study locations should be <br /> visited once at the beginning of each field season, and once <br /> at the end of each season. In addition, SGC needs to <br /> characterize the conjunctive flow (surface flow plus ground <br /> water flow in the alluvium) of Cement Creek, in order to <br /> determine if there is an increase in this total flow once the <br /> bulkheads are installed. This can be done most easily by <br /> measuring stream flow at a narrow point in the valley were the <br /> creek is passing over bedrock (i.e. where all flow is on the <br /> surface) , if no such locations exist in the area of interest, <br /> piezometers will need to be installed to determine the amount <br /> of flow through the alluvium, and to determine the bedrock <br /> profile at the gauging station. <br /> The WQCD has indicated that they may have input into how the <br /> seep study is to be conducted (see attached letter) . Be <br /> advised that any approval of TR-14 that may be forthcoming, <br /> would likely include a stipulation that SGC satisfy <br /> requirements made by the WQCD under applicable clean water <br /> laws and regulations. <br />