Laserfiche WebLink
materials that create a toxic leachate. Water that infiltrates the fill may reach <br />Scullion Gulch. However, due to the small area of disturbance relative to the <br />entire drainage basin for Scullion Gulch, this will be a very minor <br />contribution of flow in the creek. <br />The permittee will be obtaining part of the required water supply from the <br />White River Lagoon, as discussed earlier. Approximately 552 ac. ft. per year <br />(601 gpm) will be pumped from the lagoon to a head tank in the D-Portal <br />area. This is less than one percent of the low flow of the White River. <br />Therefore, impacts will not be significant. <br />Recharge of the ground water is not expected to be impacted significantly by <br />the proposed mining operation. The majority of the recharge area for the <br />Mesaverde aquifers is outside of the mine plan area. It is possible that <br />surface fracturing resulting from subsidence could increase recharge to the <br />Upper Williams Fork.. However, these cracks, if they occur, are expected to <br />exist for only a short period of time before naturally sealing. <br />Recharge of the White River alluvium by bedrock aquifers is not considered <br />to be significant because of the low transmissivities of the aquifers. The <br />permittee has estimated that total discharge could be 1.3 gpm through <br />bedrock aquifers to the White River, which is less than a tenth of a percent of <br />the base flow of the river. Therefore, the expected change in the recharge <br />capacity of the bedrock aquifers would not be a significant impact to the <br />alluvial aquifer. <br />The surface recharge capacity of the alluvial material in Scullion Gulch may <br />be reduced due to the construction of cuts and fills in the portal areas. This <br />disturbed area is small relative to the total area of Scullion Gulch and <br />therefore impacts are expected to be very minor. <br />Due to the presence of Kenney Reservoir, water withdrawal from the White <br />River lagoon will not cause measurable drawdown in the alluvium at the well <br />field site. The quantity of water that will be pumped is less than one percent <br />of the low flow of the river. <br />In summary, the impact of the proposed mine on ground water will be <br />localized, with no significant impacts expected on a regional basis, due <br />primarily to the small quantity of ground water in the area. <br />No significant cumulative hydrologic impacts are expected as a result of the <br />mining activities at Deserado Mine. The Division finds, in accordance with <br />C.R.S 34-33-114(2)(c) and Rule 2.07.6(2)(c), that the operation has been <br />designed to prevent material damage outside the permit area. <br />Deserado Mine 36 June 18, 2009