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MY1VE ID # OR PROSPECTING ID # M-77-493 <br />INSPECTION DATE 7/2/98 INSPECTOR'S INITIALS ACS <br />This inspection was conducted primarily to assess environmental protection facilities and storm <br />water controls upgradient of Eagle Park Reservoir. These facilities and controls are pertinent <br />to the Division's review of pending permit revision SR-02, which is a request for a finding <br />that the post mining land use of developed water resources has been established in Eagle Park <br />Reservoir. <br />There are two primary areas of seepage of process water below Robinson Lake. The upper seepage <br />area consists of toe seepage from the dam and is most likely related to internal drainage <br />features incorporated into the design and construction of the dam. It was agreed that the <br />operator would search records for a cross section illustrating the internal structure of the <br />dam and provide copies of available information to the Division. Robinson dam toe seepage is <br />collected and routed to the Robinson seep pump back sump which has been described in previous <br />inspection reports and is an approved environmental protection facility. The overflow culvert <br />that was previously present in the Robinson seep collection sump has been removed, and the <br />downstream side berm of the sump has been built up and stabilized in the area of the removed <br />culvert. Seep water collected in the sump is returned to Robinson Lake via either or both of <br />two pumps and two return pipelines. The second area of Robinson Lake seepage is located in <br />a low, bowl shaped area below the Robinson seep collection sump, but topographically above the <br />Robinson ground water cutoff wall. These seeps are routed to a basin that has been recently <br />excavated just above the concrete ground water cutoff wall. The collected seeps are impounded <br />against the upstream face of the concrete cut off wall, which has been exposed to a depth of <br />approximately three feet. The seepage impounded in the basin infiltrates into the ground water <br />cut off pump gallery and is returned to Robinson Lake. As a contingency measure, a pump has <br />been placed into the ground water cut of wall basin that can pump water from the basin back <br />the Robinson seep collection sump. At the time of this inspection, there was very little water <br />impounded behind the cut of wall, and it appears that the capacity of the basin and the rate <br />of infiltration to the pump back gallery is adequate to contain the lower Robinson Lake seeps. <br />Since 1998 was a relatively light snowmelt year at Climax, the sizing of the ground water <br />cutoff wall basin has not been subjected to worst case, high runoff conditions. However, with <br />the contingency available to pump out of this basin, containment of Robinson Lake seepage is <br />assured, and the basin can be enlarged or other containment measures implemented if warranted <br />based on observations of performance during normal or high runoff years. <br />Ditchwork and culverts have been installed upgradient of the Robinson seep collection sump and <br />the ground water cutoff wall for the purpose of diverting clean runoff around these facilities. <br />There are areas of non point source pollution, roads and related ground disturbance, in the <br />source areas for the diverted runoff. Roads that are no longer needed are being reclaimed by <br />backfilling and revegetation. One such road was inspected. The backfilling has essentially <br />restored original contour and the second year growth of vegetation was showing a good <br />percentage of cover. <br />The area between the Chalk Mountain intercept and the Eagle Park Reservoir was inspected. This <br />area is located above the steep slopes that are present along the south shore of the reservoir <br />at its east end. In order to enhance the stability of this steep slope, Climax has committed <br />to routing runoff around the steep slope area. However, it was observed that runoff from the <br />road along the south reservoir perimeter would flow on to the steep south shore slope. Since <br />this site inspection triggers the 60 day period during which the Division must make a decision <br />on revision SR-02, it was agreed that storm water control improvements would be implemented <br />along the south reservoir shore within that 60 day period, and the Division would reinspect <br />the site. It was also observed that small amounts of trash, in the form of wood, steel cable, <br />etc., are scattered in areas that are below the ultimate high water line of Eagle Park <br />Reservoir. It was agreed that these areas would be cleaned-up prior to the Division's <br />reinspec lion within the next 60 days. Given the current rate of inflows to the reservoir and <br />the water level in the reservoir, it does not appear that it will be filled this season. <br />The 4-Dam seep collection ponds were inspected. It was observed that improved, deepened ditch <br />work had been installed to route runoff around the collection ponds. It was further observed <br />