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The entire Roatcap Creek system contains no alluvial deposits due to the steep <br />topography and overall drainage gradient. One irrigation ditch, the Overland <br />Ditch, follow the topographic contours between the upper Roatcap Creek <br />Drainage Basin to the upper West Muddy Creek Drainage Basin. <br />There are many springs and numerous ponds within the permit and hydrologically <br />adjacent area of the Orchard Valley Mine. It appears that most of these <br />springs and ponds are intermittent and depend upon seasonal precipitation and <br />long-term weather patterns. The source of most of the springs appears to be <br />related to landslide complexes, faults and fractures, areas of <br />colluvium/alluvium where ground water has accumulated, or the discharge points <br />at the contact of the Rollins sandstone with the lenticular sandstones of the <br />Mesa Verde Formation. <br />IMPACTS ON SURFACE WATER <br />Several activities or occurrences related to mining operations could have an <br />impact on surface water quality or quantity. <br />o Runoff from disturbed areas would carry higher sediment concentrations. <br />However, all the mines employ approved sediment control systems while the <br />sites are disturbed. After successful reclamation, the sediment control <br />systems are removed. Therefore, receiving streams are not expected to be <br />impacted by disturbed flows. <br />o Salinity levels in receiving streams could increase as a result of <br />pumping from underground workings. Currently the only mine discharging <br />water from underground workings on a permanent basis is Mt. Gunnison <br />No. 1. Orchard Valley and HaMc's Nest mines are not currently <br />discharging, but the assessment assumes they are contributing discharge <br />to the 1Jorth Fork of the Gunnison River as well. The assessment <br />indicates that no significant impacts will occur on the North Fork of the <br />Gunnison at the maximum extent of disturbance and no water uses will be <br />precluded by poor water quality. <br />o Effluent from several waste piles will enter the North Fork of the <br />Gunnison River. Virtually every operation except the Terror Creek <br />Loadout has same form of waste rock/coal refuse pile, either existing or <br />proposed. In addition, several historic waste piles also exist in the <br />valley. These structures all contribute dissolved solids through <br />leachate discharge. This assessment indicates that the leachate will <br />cause a 7% increase of total dissolved solids during average flow. <br />Nowever, this is probably an over estimation since seepage from the piles <br />will occur as a result of snowmelt and at that time, stream flows are <br />much higher than average. <br />o Subsidence in the North Fork Valley could modify the area's surface water <br />hydrology. Storage capacity of ponds and impoundments could be reduced. <br />Therefore, monitoring is currently being conducted at the Orchard Valley <br />Mine at stockponds which could be affected. <br />-12- <br />