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<br />• about 30 gpm when the production increases to 2 million tons <br />per year. Thus, the current cumulative inflow projection, <br />42 gpm, would be less than the 100 gpm inflow projected in <br />OSM's November 1987 Environmental Assessment. <br />Water consumption to support mining activities is not <br />expected to change under the proposed mining plan <br />modification. Net annual water depletion would be expected <br />to remain close to or less than the estimated annual net <br />depletion of 13.1 acre feet per year. <br />The addition of ramp and B-seam mine development waste <br />materials to the lower refuse pile would have no impacts on <br />the North Fork of the Gunnison River alluvium. The lower <br />refuse pile has two underdrains to handle the perched <br />aquifer which is expected to develop at the base of the <br />pile. At this time no aquifer has developed. Four out of <br />five monitoring wells next to the pile are dry, suggesting <br />that there is little flow through the pile or surrounding <br />substrate. <br />The proposed mining in the B seam would not result in a <br />substantial loss or reduction of long-range productivity of <br />the water supply in the mine vicinity, including aquifers <br />and aquifer recharge areas. <br />• c. Unstable geology concerns <br />Landslide or rockfall activity would not substantially <br />increase due to subsidence effects. Subsidence cracks in <br />soil and unconsolidated materials would be filled, thus <br />limiting infiltration and the resulting buildup of water in <br />these deposits. If movement of the existing slope-failure <br />area and rockfall areas above the B-seam mining area did <br />occur, the resulting effects would be minor due to the <br />remoteness of the area and arid nature of the surface <br />resources. <br />d. Threatened or endangered species <br />The proposed mining plan modification would not affect <br />any of the threatened or endangered species currently listed <br />for the area. Net annual surface water depletion would be <br />expected to remain close to or less than the estimated <br />annual net depletion of 13.1 acre feet per year. USFWS <br />concurred with OSM's assessment in their biological opinion <br />dated July 14, 1989. <br />e. Migratory birds of high Federal interest <br />The mining plan modification proposed subsidence of the <br />• area where the Cooper's hawk nest located. Such disturbance <br />12 <br />