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<br /> <br />After the cessation of mining operations, mine water from the New Elk <br />Mine would no longer be discharged, and the abandoned workings would fill <br />with water, a process taking up to 80 years. The piezometric surface <br />would partially recover. Because the underground workings lie 400 to 800 <br />feet below the surface, the piezometric surface of the coal aquifer would <br />not be expected to rise to a level where it would intersect the ground <br />surface and thus cause discharge. A permanent depression in the <br />piezometric surface would exist in the vicinity of the flooded mine <br />workings. Given the assumption that the Allen seam is hydrologically <br />similar to the Maxwell seam, the depression may extend to a distance of 2 <br />vv~ _;.^~,_~~ ,--~ to 3 miles from the edge of the mine worki ngs. <br />- When pumping of water from the workings is discontinued, the water that <br />accumulates is expected to be of lower quality than that currently pumped <br />due to increased residence time (Exhibit 6, Table 5). The quality of the <br />stagnant mine water should be similar to the quality measured below the <br />New Elk waste piles (Exhibit 6, Table 13). Total dissolved solids may be <br />equal to or exceed 2600 mg/1. This mine water would spread as a plume of <br />degraded quality ground water down gradient from the mine. Based on the <br />structural contours of the coal seam, water passing through the flooded <br />workings would move in a northeasterly direction. It may spread to <br />approximately 2 to 3 miles from the edge of the mine workings. It is <br />anticipated that soluble materials would be readily flushed from the mine <br />cavity, but flow would be very slow away from the mine due to the low <br />permeabilities of the coal, causing the flushing action to persist over <br />an extended period of time. Since the coal seam aquifer contains poor <br />quality water, 806 to 1100 mg/1, and is not used as a water supply in the <br />general area, mining within this aquifer will not materially damage the <br />quality of ground water used off site. <br />Pcst-mining effects of the New Elk tdine <br />stream-alluvial aquifer system would be <br />operations, because mine water would no <br />underground workings. Therefore, seeps <br />the only source of pollutant and this, <br />negligible. <br />on the water quality in the <br />expected to be less than during <br />longer be discharged from the <br />le from the refuse piles would be <br />as indicated earlier, is <br />Cumulative Hydrologic Impacts of Mining <br />Because of their proximity to each other, the New Elk and Golden Eagle <br />Mines do cumulatively impact the surface and ground water systems in the <br />area. The cumulative hydrologic impact study (CRIB) prepared as part of <br />the original Findings document was restricted to that part of the <br />Purgatoire River Basin above Madrid, Colorado. Such a restriction is <br />practical since only one other permitted operation lies in the general <br />area. The Raton Creek Mines, operated by Energy Fuels t4ining, are <br />located approximately one and one-half miles due south of Trinidad, some <br />20 miles east of Golden Eagle and New Elk. One additional mine, so far <br />unpermitted is also a concern. This is the Rimrock Strip Mine which lies <br />approximately one and one-quarter miles northeast of the Raton Creek <br />Mines. The Rimrock Strip Mine has qualified for the Small Operator's <br />Assistance Program. Filing of a permit application for this operation is <br />anticipated in late 1988 or early 1989. <br />-25- <br />