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The quality of this mine inflow water differs from surface water sampled in the permanent diversion or from Raton Creek. The mine water is significantly more mineralized and conductive. Its conductivity is, however, quite compatible with water samples from two various local ground water sources including the Iuppa well, located immediately west of the mine site, and the lower Starkville Gulch spring in Section 36, The mine water does not itself exceed NPDES limits. However, discharge of this water from the sediment pond, when it does periodically occur, could more than double the quantity of highly mineralized water feeding from Starkville Gulch into Raton Creek. The base flow of the stream in Starkville Gulch is obtained from the spring in the lower part of the gulch. The ratio of the volume of this flow relative to base flow in Raton Creek was determined by baseline studies to be 1:62.5. As a worst case, if mine inflow were directly added to the base flow of Starkville Gulch and conveyed to Raton Creek, there would only be a calculated 4 percent increase in the mineralization of the creek, ie., from a TDS value of 524 to 544. This is neglible. The added volume of water, on the other hand, would be a beneficial result. Surface subsidence in South Starkville Gulch resulting from retreat mining in the underlying Animas workings became a concern during the first permit term. Approval of the revision allowing the extension of the mine into this area, however, was in part the result of the findings that the probable hydrologic consequences of this mining would be minimal, both on and off the permit area. The probable hydrologic consequences of adding the three railroad loadouts in the City of Trinidad to the permit area were also determined to be minimal prior to approval of these revisions to the Animas Mine permit. The present and proposed operations are in compliance with the requirement of this section. Cumulative Impacts Assessment The original Findings document found no potential for cumulative effects on the hydrologic balance by the Animas Mine and the nearest other coal mining operations at the time, the Allen and Maxwell Mines. These mines are currently operated by Wyoming Fuel Company as the New Elk and Golden Eagle Mines, respectively, along the Purgatoire River some 20 miles west and upstream. This finding remains true. There is, however, under current consideration by the Division, a proposal by Rimrock Coal Company under the Small Operators Assistance Program to permit a strip mine in the NW 1/4 Section 29-T33S-R63W. This mine would be located approximately one and one-quarter miles northeast of the Animas permit area. The total permit area of the Rimrock Mine is estimated to be approximately 20 acres; the coal seams to be mined are interpreted by the Division to he the rough strati graphic equivalents of the upper and lower Starkville seams being mined in the Animas operation. The potential surface hydrologic impacts of the Rimrock Mine would be limited to drainages separate from and northeast of Moore's Canyon. Operations in the Animas Mine did not impact these drainage during the -16-