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likely increase overall health risks to the general public due to factors inherent in the remedial <br />measure itself. Mine dewatering would transfer large amounts of contaminants from a deep, <br />flooded and geochemically stable underground environment out to the active surface <br />environment. Subsequent water treatment would require expanded water treatment facilities, <br />construction of large evaporation /sludge retention ponds, regular production and /or transport of <br />chemicals, fuels and other hazardous materials, and long -term management and potential offsite <br />disposal of contaminated sludges. <br />Any number of these factors, alone or in combination, could increase the potential for additional <br />and /or other types of impacts to water quality in Ralston Creek (such as fuel, chemical or sludge <br />spills), and several could increase offsite potential for health risks to members of the general <br />public. Offsite production, container transfers, and transport of chemicals, fuels or other <br />hazardous materials through populated areas, along with potential transport, disposal and long- <br />term offsite management of contaminated sludges, each introduce potential risks with respect to <br />human intakes or exposures. Offsite requirements could also increase physical risks to members <br />of the general public due to increased potential for related industrial and transportation accidents. <br />To summarize overall health risks with respect to mine dewatering/ active treatment, a hydraulic <br />gradient reversal strategy would require a major engineering and industrial undertaking that <br />poses peripheral /indirect health risks to members of the general public in order to potentially <br />achieve a partial reduction in uranium concentrations in Ralston Creek. Mine dewatering with <br />active water treatment is likely to result in a significant net increase in overall potential health <br />risks to the general public and thus rates poorly under Criterion 3. <br />With respect to minimization of environmental impacts (Criterion 4), the Federal Remediation <br />Technologies Roundtable group indicates that "Because the use of various treatment <br />technologies can have a significant impact on a site's natural resources, careful consideration of <br />these effects should be made when selecting technologies for cleanup." (FRTR, 2008). Mine <br />dewatering /active treatment would expand and prolong local disturbances and impacts to <br />terrestrial, aquatic and riparian habitats and ecosystems with potentially detrimental effects to <br />local wildlife (including the endangered Preble's Meadow Jumping Mouse). Habitat disruption <br />or destruction would inevitably result from the need to expand industrial facilities, construct <br />evaporation/sludge retention ponds, and actively operate the site for many years including <br />increased industrial traffic through Bear Tooth Ranch and along Ralston Creek with shipments of <br />equipment, chemicals, fuels, and potentially, contaminated sludges. <br />Considering the preceding conceptual assessments of mine dewatering /active treatment with <br />respect to the four remedial Criteria, individual Criterion ratings for this remedial alternative <br />have been conservatively estimated as follows: <br />Criterion <br />1. Effectiveness = <br />2. Sustainability = <br />3. Health Risks = <br />4. Environmental Impacts = <br />Rating (and summary rationale) <br />5 (partial mitigation, delayed beneficial effects, new risks) <br />2 (low cost effectiveness, high O &M) <br />2 (overall increase in health risks due to method itself) <br />2 (significant increase in environmental degradation) <br />6 <br />