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In some cases, one remediation method might be tried, such as source controls, <br />but more metals may need to be removed. After the source controls are implemented, <br />passive treatment may be needed- The potential for this additional treatmern is noted <br />under Phase 2 of the treatment methods on the spreadsheets. Phase 1 may not be <br />successful or only minimally. Therefore Phase II costs are a summation of the two <br />phases- Several sites are currently listed as "no action". After careful evaluation by the <br />Prioritization Committee these sites were considered having a low poternial of <br />contributing metal loads to receiving streams. <br />As with the mine waste characterization, estimated costs for remediation aze <br />based on best professional judgment and aze site specific. Administration and <br />contingency costs aze not included for individual sites but aze added to the overall costs <br />of the remediation scenarios described in the next chapter. Four cost ranges have been <br />applied: under $20,000, $20,000 to $100,000, $100,000 to $500,000, and greater than <br />$500,000. Some sites were Jiff cult to fully assess and available remediation methods <br />did not appeaz to be practical to apply, particulazly without father investigation For <br />these sites, costs reflect the next steps for further evaluation but do not include estimated <br />percentage reductions since the most appropriate remediation method is not known at this <br />time- The specific estimates for all sites are shown on the spreadsheets. <br />The rank and prioritization spreadsheets were designed to focus remediation on <br />locations where the lazgest benefits could be realized for the effort and resources <br />expended. They were not developed specifically for the UAA and are expected to change <br />as more information becomes available. However, they are very useful for setting up <br />different scenazios describing what metal reductions may be possible and at what cost, if <br />a certain number of sites were remediated. Those scenarios aze described in the next <br />chapter. <br />Loading from the Largest Adit and Mine Waste Sources <br />The edits have been ranked, using the weighting factors discussed in Section II, on <br />the basis of both high and low flow loading of seven metals plus pH. Most high flow <br />samples were obtained in June or July, while tow flow loads were obtained in September <br />or October. These figures may overestimate low-flow loading since eazly fall stream <br />flows had not yet dropped to levels seen in wirner mornhs. Loads from the Kohier, <br />Bandora, ?North Staz, and Evelyn mines were sampled frequently. <br />Selection of sites to be included for possible remediation is based upon the combined <br />rankings of all sites within the Upper Basin {Appendix l0E - UAA). Many sites were <br />previously categorized as "no action" because of thew low total contributions and <br />remoteness and,~or low concentrations. The loading from the top ranking 33 edits, <br />including a few large loaders lacking either a high or a low flow sampling datum, are <br />shown in Table 11.1. These are current loading figures and do not include any potential <br />reductions. Eighty nine percern of the loading from all edits comes from these top 33 <br />sites. <br />Mine waste piles have been ranked in a similar fashion as edits including the same <br />weighting factors, except that they are ranked by metal concemration determined by the <br />leach test instead of load (Appendix 11 A - UAA). Table 11.2 lists the top 26 mine waste <br />17 <br />_= - = = - _ <br />