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Memo to Steve Shuey 2 March, 25 2004 <br />Logan Wash Portal Closure Permit No. M-1977-424 <br />The Operator has proposed weekly monitoring of the portal during the "spring runoff season." The <br />period of time during which monitoring will occur must be more specifically defined in the pernut to <br />include the eazliest date that the mine has started making water, over the period of record 1993-2003, <br />and the latest date that the mine has dried up. During particulazly dry yeazs, the Operator could request <br />variances from DMG for the period during which monitoring will be required. Weekly monitoring <br />appears to be suf&cient, in that with a flow rate of tlu~ee gpm; which is the historically high discharge <br />rate for the mine, only 4,043 cubic feet of water would be collected behind the dam over seven days. <br />Another condition that DMG will impose is that if water pressure reaches 1.5 psig, the Operator will <br />open the valve and draw down the mine pool to a safe level and in accordance with the site CDPS <br />permit. For reporting to DMG on the results of the weekly inspections, immediate (within 24 hours) <br />notification will be required if pressure exceeds 1.5 psig or if instability such as seepage, or any other <br />problems at the portals are observed. Otherwise, a summary of the inspection results in the annual <br />reclamation report will suffice. <br />By impounding water behind the concrete dam and compliance with the DMG stipulations, the <br />Operator will be able to evaluate the soundness and safety of the portal closure currently in place. <br />ARer water begins to impound behind the dam, the Operator and DMG will be able to evaluate <br />capacity of the rock formation to dissipate The water. If dissipation can be demonstrated during a wet <br />year without the need to dischazge and without exceeding 1.5 psig, then the existing closure or some <br />variant thereof maybe approved for final reclamation. Otherwise, alternatives for portal closure, such <br />as a full concrete bulkhead or long-term management of discharge will have to be considered. <br />In addition to the structural aspects of the portal closure, the Operator and DMG must evaluate its <br />effectiveness in terms of preventing the release of mine water to surface streams in the form of springs <br />and/or seeps. The DMG requires a demonstration that there is no near term short-circuiting from the <br />mine pool to the surface. Monitoring programs have been used at other bulkheaded mines in Colorado <br />to satisfy this requirement. At the Bulldog Mine, Permit No. M-1977-215, the mine pool was <br />inoculated with a tracer and tracer samples were collected in the adjacent stream for a set period. AY <br />Climax (Permit M-1977-493), at Sunnyside (Permit M-1977-378), and at Rajah 30 (Permit No. M- <br />1977-294), other types of monitoring programs to detect surface discharge from a mine pool were <br />approved. It is suggested that a suitable monitoring program be applied at Logan Wash as soon as <br />possible; given the extremely dry winter in Colorado this yeaz and the dry spring we have so far <br />experienced, it is unlikely that substantial amounts of water will be impounded in the mine this year. <br />As a result, this yeaz can be used to collect baseline water quality data and establish a monitoring <br />program that will be useful for the next wet yeaz that Colorado will experience. <br />cc: Carl Mount, DMG (via email) <br />c:\acsVvfy Documents\logan wash portal closure.doc <br />