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Logan Wash Mine TR No. 6 <br />2.5 Mine-Water Management <br />To reduce the monitoring activities at the Research Mine, the permanent management of mine <br />water in the Reseazch Mine was investigated. Options identified to manage potential dischazging <br />mine water included: <br />1) Allow potential discharge to continue under and continue the sampling program <br />required under the existing NPDES permit, <br />2) Allow potential dischazge to occur, but pipe the dischazge to the location of the L-1 <br />Portal discharge point now located in upper Dry Gulch northwest of the main L-1 <br />Portal, <br />3) Plug the edit with an engineered concrete plug to prevent discharge from occurring, <br />4) Conduct a local water quality survey of springs in the area with the intention of <br />comparing these data with mine-water dischazge quality. If the data were comparable, <br />a defendable argument would be proposed to allow dischazge of the mine water <br />without a NPDES permit. <br />Option 1 was not a preferable option because it would require significant monitoring and <br />sampling under the existing NPDES permit program. Option 3 was rejected because of the <br />expense and difficulty of constructing a reliable edit plug. Because of the prevalent bedding <br />fractures in the shale, a 100 percent effective seal would be difficult to construct. Also, this <br />option would require a thorough monitoring program. Option number 4 was rejected afrer an <br />initial sampling of local springs did not support similar water chemistry from the mine. Option <br />number 2 was therefore chosen as the preferred alternative because it would reduce the number <br />of permitted NPDES outfalls at the mine to one, and therefore reduce monitoring costs. This <br />action has been verbally approved by CDPHE. <br />3.0 Mine Drainage Design <br />The final closure of the Research Mine portal will involve the construction of a buried pipeline <br />that will provide free drainage of the mine discharge. The components of the proposed action <br />include pipe alignment and materials, pipe sizing, and trench construction and pipe installation. <br />Drainage system monitoring is discussed in Section 4.0. <br />3.1 Pipe Alignment and Materials <br />The mine drainage alignment will extend from the Reseazch Mine vault along the Lower Bench <br />access road to the Lower Bench vault and from the Lower Bench vault to the upper reach of Dry <br />Gulch. The alignment is approximately 3000 feet long (see Figure 1). <br />Western Water 8 Land, Inc. <br />