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Page 5 of 10 <br />2. Objection: To evaluate leachate, the Operator is relying on Meteoric Water Mobility Procedure <br />( "MWMP "), which cannot factor into the equation larger rock sizes, rather than the more rigorous <br />Fortran Analysis Program ( "UNSAT -H "). In order to ensure that the impacts to water quality are <br />minimized, the Division should require the Operator to release meteoric water mobility procedure <br />( "MWMP ") leachate testing computer data. August 2009 Letter, 3. <br />The Division's Response: Contrary to the Objectors' assertions, MWMP tends to overestimate <br />concentrations of contaminants in leachate. MWMP is designed to evaluate finer grained rock <br />particles. In this case, the development rock areas contain rock that is too coarse to be analyzed <br />by the MWMP testing apparatus. The result is that the larger rocks were either excluded from the <br />analysis or broken into smaller pieces. Leachate chemistry is controlled by water -rock <br />interactions, which occur on the surface of the rock particles where water and minerals interact. <br />Finer grained materials have a much higher ratio of surface area to mass, and the chemistry of <br />leachate is controlled dominantly by the fine grained materials. Therefore, the Operator's use of <br />MWMP, which cannot account for the larger rocks in the development rock areas, would tend to <br />overestimate concentrations of deleterious substances. The Operator has included the results of <br />the MWMP testing in Attachment B of the EPP. <br />3. Objection: The Division should require the Operator to create a fund for the perpetual treatment <br />of water entering the mines. August 2009 Letter, 5. <br />The Division's Response: The Division has required the Operator to post a financial warranty <br />sufficient to ensure that disturbances to the prevailing hydrologic balance will be minimized. As <br />always, the Division will not release the bond for this operation until full compliance with the Act <br />and Rules has been demonstrated. <br />4. Objection: Operator's statement that, "where BMPs have failed... they will be addressed as soon <br />as possible," should be revised to read "where BMPs have failed... they will be addressed as soon <br />as it is safe." This change should be made because "possible" can be interpreted in many <br />different ways (e.g. `when I get around to it'). August 2009 Letter, 5. <br />The Division's Response: The Division does not interpret "as soon as possible" to mean "as soon <br />as the operator gets around to it." BMPs are designed to minimize potential for failure. <br />However, in the event that repairs are necessary, the expectation of safety goes without saying in <br />all mining operations, and is included in the assessment of whether or not repairs are possible. <br />5. Objection: Since the affected area of the West Sunday Mine lies on the Morrison Formation and <br />Burro Canyon Formation, and where saturated, these formations create the potential for <br />groundwater recharge to the Dakota Aquifer, the Division should require the Operator to <br />demonstrate how its mining activities will affect the water quality of the Dakota Aquifer and how <br />it will mitigate any risks to the same. August 2009 Letter, 4. <br />The Division's Response: The surface affected area does overlie a portion of the Dakota <br />sandstone, but the estimated depth to the upper elevation of the aquifer (the potentiometric <br />surface) is approximately 300 feet. There is no known ore deposit or saturated mine workings in <br />or above the Dakota sandstone in this permit. Inasmuch as the Operator has committed to placing <br />an impermeable liner on the ore pad, and has demonstrated that surface runoff is controlled, and <br />that percolation is limited, which limits formation and migration of leachate, the Division <br />