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Mike Thompson/M- 1982- 090/TR -4 <br />August 31, 2012 <br />Page 2 <br />The equipment storage building will house equipment and supplies for this proposed project, and it will <br />also house fuel and other fluids. Please state whether the building will have a concrete floor (or other <br />impermeable material), and what type of impermeable secondary containment will be provided for the <br />fluids and hydrocarbons that will be stored onsite. <br />The description of the pipe support spanning Imogene Creek is not sufficient. The drawing appears to be <br />a plan (top) view, but a side view is needed also. Please provide information about the concrete <br />foundations supporting the ends, including materials and drawings (from top and side). Details regarding <br />the anchoring of the span to the foundations and securing the pipe to the span are needed. <br />The non - functional Parshall flume that is currently on the site will be replaced, presumably to be able to <br />monitor future discharge flows. Will the new Parshall flume be galvanized steel construction or a durable <br />non -metal composite material? There is no mention of any problem with the current concrete structure <br />around the Parshall flume, nor that replacement of it is needed. Please clarify if replacement work is <br />needed for the concrete structure around the Parshall flume. <br />Since nearly all work related to portal rehab has the potential to increase sediment loading of the portal <br />discharge, the sediment pond and its conveyance pipe must be installed before the portal work may <br />proceed. Please confirm. <br />Please provide more construction details of the proposed snow shed that will connect the covered portal to <br />the equipment storage building, such as dimensions, materials, and footers. <br />The hydrologic monitoring data you provided indicate that there has been little change in discharge water <br />quality over time, though much of that was during time when the mine was inactive, especially <br />underground where the discharge originates. The data, however, do not constitute a "baseline," as <br />required per Hard Rock/Metal Rules 3.1.6 and 3.1.7. The Division approves the surface water monitoring <br />locations, analytes, and the sampling schedule you propose. This sampling program must commence this <br />season and continue at least until five consecutive quarters have been collected and baseline conditions <br />can be demonstrated. The proposed surface earthwork and portal rehab work may commence upon <br />approval of the technical revision, but please be advised that no mining may occur until such time that the <br />hydrologic baseline conditions are established. <br />The breakdown of reclamation tasks and direct costs appears adequate. Please be reminded that this <br />office must also add indirect costs such as reclamation contract administration and contractor overhead <br />and profit. <br />The decision date is set for September 12, 2012. Please provide two copies of your responses to me prior <br />to the decision date. If additional time is needed to prepare and submit responses you may request an <br />extension. <br />