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Page 5 of 9 <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 fmancial 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: The Division should require the Operator to demonstrate how collection of storm <br />water in waste rock areas will affect leachate and demonstrate the best management practices that <br />will be used to minimize percolation of storm water into the waste rock. The Division should <br />also address waste rock berms that direct storm water towards Big Gypsum Creek. August 2009 <br />Letter, 3. <br />The Division's Response: The mine is subject to an existing CDPHE stormwater management <br />permit and plan, which require regular monitoring and maintenance. Stormwater control <br />structures are designed to meet the 100 -year, 24 -hour precipitation event. There is little to no <br />runoff from the site due to the arid climate, and unless there is a significant precipitation event, <br />runoff will not reach Big Gypsum Creek. Big Gypsum Creek is an intermittent stream, tributary <br />to the Dolores River. The creek is over one -half mile from the closest portion of the site, and is <br />