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• the size of planer surface areas of dumps, <br />• volume of material vahere estimated by DMG, <br />• distance to ephemeral streams, <br />• distance to perennial streams, <br />• biological potential of nearby streams {i. e. potential presence of aquatic life), <br />• orientation (direction) of slope (indicates when snow may melt ofd, <br />• whether or not a vegetative kill zone exists below, <br />• relative steepness of the site, <br />• ease of access, <br />• whether or not acid mine drainage runs over or through the dump, <br />• potential remediation that might be applied, <br />• rough estimate of cost of remediation. <br />Some of these characteristics require additional explanation. The planer surface areas <br />of dumps were estimated from 1998 liSGS Orthophotographic Quadrangle Maps. They <br />are considered to be overestimates because surface disturbances related to roads and <br />portal cut banks often could not be visually distinguished from the wastes. Generally, the <br />entire disturbed area vas distinguishable and therefore measured. On the other hand, <br />sites smaller than 80 to 100 square meters were not included because of resolution <br />dill culties. Although there are many small prospects that fit this category, prospects <br />seldom contain high mineral content (otherwise they would have been more extensively <br />mined). The assumption is that the overestimate of the larger waste sites is countered by <br />not estimating the prospect sites. Distances to ephemeral and perennial streams were also <br />estimated using the Orthophotographic Quadrangle Maps. <br />Several characteristics are given a relative rating. Biological potential (of immediate <br />receiving stream) is divided into three categories; low, medium, and high. L-ikewise, <br />steepness is rated, flat, moderate, or steep. Access is rated 1 through 4, with 1 being easy <br />and four being very difficult_ <br />Potential remediation techniques are divided into five categories: capping, amending <br />with neutralizing agents, removal and cleanup, hydrological controls (such as drainage <br />ditches), and consolidation of dumps. The ARSG Prioritization Committee, which is <br />made up of five professionals with extensive experience in implementing mining <br />remediation, estimated typical rates of metal removal for each technique: capping - 25%, <br />amendment - 10%, removal - 90%, hydrologic controls - 20%, and consolidation -10%. <br />These percentages are considered additive if more than one technique is applied to a site. <br />The reduction rates are also considered an average rate for the method over time. Some <br />sites may provide better results; others worse_ The spreadsheets show which techniques <br />might be best applied to particular sites. <br />Several sites are currently listed as "no action". After careful evaluation by the <br />Prioritization Committee, these sites were considered having a low potential of <br />contributing metal loads to receiving streams. There are also numerous sites that were <br />identified through Orthophotographic Quadrangle Maps as disturbed areas and have been <br />included on the spreadsheets. Leach test samples were not collected from these sites <br />because best professional judgement determined that metal and pH contributions would <br />be insignificant to receiving streams. <br />Estimated costs for remediation are based on best professional judgement and are site <br />specific. Administration and contingency costs aze not included for individual sites but <br />1~ <br />