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L Model predictions show that after 1,000 years of transport, no species of concern <br />reached the underlying water table; <br />2. Concentrations at the leading edge of the plume at-e significantly lower thatr the <br />background concentrations in the underlying aquifers; <br />3. Even using the unrealistic assumption of no sorption, the leading edge of the <br />plume as defined by a concentration of 1 millionth of the initial concentration fails to <br />reach the groundwater; <br />4. Under realistic conditions, the rock traits underlying all of the mine waste piles <br />would exhibit significant sorption characteristics that would retard the movement of <br />species of concern. As noted in the response to comments, the Mon'ison Formation <br />behaves as a geochemical trap that resulted in a Uravan Mineral Belt; <br />5. Laboratory tests on the permeability of the Summerville Formation yielded a <br />hydraulic conductivity value of less than 9.7 E-10 cm/s effectively creating an aquiclude <br />that would prevent downward migration of water to potential aquifers below the <br />Summerville. For comparison purposes, concrete has a hydraulic conductivity of 1 E-8 <br />cm/s. <br />In concIusion,the GeoSciences' report states: <br />Conservative based modeling that incorporated no sorption and relatively high <br />permeability values results in plumes that failed to reach the underlying groundwater. <br />Under unrealistic conditions using published values of sorption and permeability such as <br />laboratory tests for the Summerville Formation, then there is no viable pathway for <br />species of concern from the mining waste piles to reach regional groundwater resources. <br />III. COlti'CLUSION <br />Cotter has demonstrated that the JD-9 Mine should receive the same exemption which the <br />Division provided to the SM-18 Mine. The mine may properly be exempted because "acid- or <br />toxic-producing materials will be insufficient to adversely affect persons, property or the <br />environment." The Board should reverse the final determination of the Division that the JD-9 <br />11 <br />