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• Item I(B)(1): This item indicates a requirement for long-term stabilization of the mine pool <br />to prevent off-site excursions, or alternately, a plan for detoxification of the mine pool. <br />Cotter has already begun and intends to further pursue both of these alternatives as follows: <br />Cotter has installed highly engineered water tight bulkheads to permanently seal mine <br />portals having any reasonable potential to become inundated with mine refill water in <br />the foreseeable future. This measure was approved by the Division and was <br />implemented under TR-9. <br />2. In-situ treatment of mine pool water will be conducted to accelerate the current trend <br />of decreasing levels of uranium in the mine pool, reduce concentrations of other <br />metals, and coat interior wall rocks and mine rubble with a layer of iron sulfide that <br />will physically and chemically inhibit further geochemical leaching. <br />A comprehensive grouting program to seal any potential historic exploration core <br />holes or natural faults/fractures through which mine pool water could migrate to <br />Ralston Creek will be conducted. This program will be aggressively pursued during <br />alluvial fill excavation activities as concurrent isolation and conveyance of the creek <br />past the mine site in a temporary pipeline will dry out alluvial ground water tables, <br />maximizing access and ability to identify and seal any potential migration pathways. <br />Item I(B)(2): This item reiterates the requirement previously indicated in Item 1(B)(1) to <br />provide a plan to prevent excursions from the mine pool off site. Locating and plugging <br />potential conduits to the alluvial fill area ("AFA") is addressed in bullet 3 above, and a <br />detailed plan and TR request for this effort will be submitted to DRMS in accordance with <br />the pipeline diversion and AFA dewatering schedule. <br />The Division's contention of inevitability is dependent on transmission of contaminants <br />through either 1) geologic structures (such as veins or faults) coupled with no attenuation of <br />the contaminants or 2) flow though low permeability rocks with no attenuation. At present <br />there are no identified sources of contamination impacting Ralston Creek downgradient from <br />BPL. There are identified geologic structures and these structures existed pre-mining. <br />Hence the water in these structures that currently add water to Ralston Creek have done so <br />for hundreds of thousands of years. The water in contact with the mineralized areas of the <br />mine prior to mining undisputedly contained high levels of contaminants. The fact that there <br />is no impact now to the creek below BPL means that either there is no pathway for <br />contaminants to migrate to the creek through the pre-existing geologic structures without <br />attenuation or that the movement of contaminants through low permeability bedrock has not <br />and will not happen. The very reasons that uranium deposits exist in this area are indicative <br />of reducing and other geochemical conditions in local geologic materials that favor <br />immobilization of uranium and other metals. <br />If the Division's theories about Schwartz Trend migration are correct, water quality impacts <br />at the intersection with Ralston Creek were likely occurring for millennia prior to mining, yet <br />decades of water quality monitoring data along the creek have revealed no evidence that this <br />is occurring now or has ever occurred in the past. To provide further evidence concerning