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these areas are estimated from 2 to 20 gpm. It is <br />anticipated that the flow will be in the middle or <br />tower end of the range. <br />If flows into the mine approached the maximum <br />estimated, 20 gpm, this would only be approximately <br />14 percent of the peak spring runoff flow. For this to <br />occur or deplete spring flow, a direct fracture <br />connection to the mine workings must occur and remain <br />open. To date, this has not occurred in Lone Pine <br />Gulch in the F seam under cover as low as 120 feet. <br />The water balance will not be significantly affected <br />even if the maximum estimated inflows occur, since any <br />mine inflows will ultimately be discharged back to the <br />North Fork of the Gunnison. <br />Refuse Material Disposal Impacts on Ground Water <br />Lower Refuse Disposal Area - Refuse is generated <br />through the mining process and will be disposed of <br />on the Lower Refuse Disposal site. The lower <br />refuse pile is permitted for permanent disposal of <br />1.7 million cubic yards of mine development waste, <br />coal processing waste, and sediment pond cleanout <br />material. <br />To date the lower refuse pile has not impacted the <br />ground water zone near Sylvester Gulch. Because of <br />the low permeability of the colluvial soils and the <br />lack of a ground water table near the surface in <br />the colluvium, no impacts on ground water are <br />anticipated. Water monitoring well SG-l, located <br />near the site of the soil stockpiles, other water <br />quality monitoring stations on Sylvester Gulch, and <br />sites above and below the mine on the North Fork of <br />the Gunnison, provide sufficient baseline water <br />quality information to evaluate the changes in <br />water quality that could result from the impacts of <br />this refuse stockpile. Conductivity and TDS from <br />samples of monitoring well GP-1 showed slightly <br />higher levels in 1986. However, this does not <br />appear to be a continuing problem. Concentrations <br />of iron during 1991 were higher than the baseline <br />monitoring data, which the operator believes may be <br />associated with B development waste. Concentra- <br />tions of iron will be monitored to see if the <br />elevated levels continue. <br />A leachate study of the F seam refuse was conducted <br />and included in the application for the permanent <br />refuse disposal site in Exhibit 51 of the permit <br />application. In addition, the effects of B seam <br />refuse on leachate were also evaluated antl can be <br />-40- <br />