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To: Jared Ebert <br /> Date: December 29, 2017 <br /> Page 17 <br /> respectively. Thus, the drain system as designed has more than adequate capacity to <br /> move groundwater around the perimeter of the lined gravel pits. Calculations <br /> documenting this result are attached as Attachment 9. <br /> Comment 34 <br /> Based on the location of the perimeter drain of the mine area south of the Little Cache La <br /> Poudre Ditch, the drain makes several right angle turns around Parcel Numbers <br /> 9828000019 and 9828000018. Having water flow make those turns may be difficult. <br /> LRM may want to consider revising the backfilling plan for this parcel and placing the <br /> perimeter drain in a location avoiding these turns. <br /> Response 34 <br /> The purpose of the turns is to return groundwater to Parcel Numbers 9828000019 and <br /> 9828000018 after mining. Note that the right-angle turns will be gentle bends (Exhibit G, <br /> Sheets 1 and 2). Given the nature of the turns and the flow rate carried by the perforated <br /> pipe, the head loss due to these turns are minimal, and the pipe should function as <br /> intended. <br /> Comment 35 <br /> Is the Little Cache La Poudre Ditch that passes through the site lined? If not, how will <br /> LRM prevent losses from the ditch during dewatering? If there is a potential for losses to <br /> occur from the ditch, how will LRM monitor the inflow and outflow of the ditch to <br /> measure these losses? Please provide a monitoring plan and either a mitigation plan or <br /> loss prevention plan <br /> Response 35 <br /> The Little Cache Ditch is not lined through the site. However, the ditch company <br /> performed a leakage analysis (measuring inflow and outflow up and down gradient of the <br /> site) recently, and they have indicated that the ditch leaks very little through this section, <br /> indicating that natural siltation has likely sealed up the ditch. The Taylor and Gill ditch is <br /> sealed on the west side of the site as it is conveyed through concrete sewer pipe. <br /> LRM is in contact with both the Little Cache and Taylor and Gill ditch companies. <br /> Agreements have been signed to commit LRM to providing mitigation should ditch <br /> losses become excessive (Attachments 10 and 11). <br /> Response to DRA1S comments T E L E S T O <br />