2009-04-13_REVISION - M2008012 - Laserfiche WebLink

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Table 1 - Parameters that exceed Colorado Water Quality Control Commission (CWQCC) drinking water standards Parameter Drinking Water Standard*(mg/L) Result (mg/L) Iron 0.3 19 Manganese 0.05 0.89 Molybdenum 0.035 0.94 Uranium 0.03 0.38 Vanadium 0.1 0.40 Sulfate 250 1930 Radium (226+228) 5 (pCi/1) 14.1 (pCi/1) Total Dissolved Solids 500 3500 *Source: CWQCC, Colorado Department of Public Health and Environment, 2008 These wells will be tested quarterly and if ground water is found, it will be sampled and analyzed in accordance with DRMS and CDPHE regulations. The lower Morrison is comprised of interbedded shales and siltstones which form an effective aquitard and prevent any potential downward migration of groundwater. Below the Morrison, shale and mudstone of the Summerville Formation acts as a confining unit further separating the Morrison from aquifers within the older Entrada sandstone (locally called the Slick Rim), Navajo sandstone, Kayenta formation, and Wingate sandstone. (d) This Mesa has historically had dry mines. The limited water which may exist in abandoned mines is from open shafts, vents or drill holes which were not properly abandoned. It is anticipated that any free water existing in the mines may be used to wash down faces for examination, and if mines are re-opened, the water will be utilized in drilling operations within the mine. (3) Project Water Requirements The mining and exploration activities planned for the Last Chance Permit will require less than 100 gallons of water per day for dust control. (4) Sources of Water to Meet Project Requirements The water will either be hauled in daily on water tanks on the support vehicles. (5) Statement Regarding Application for NPDES Permit Given the dry nature of the Davis Mesa and the minimal project water requirements, no discharges of water are anticipated and safeguards will be in place to prevent any. Last Chance Mine - April 2009 G-2