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the Mountain Top waste rock; while a fourth sample from a biased location to characterize a potentially <br />acid generating material (referred to as 'yellow') was also obtained. There are two suites of analysis <br />within the Table; TCLP and ABA parameters. <br />TCLP metals analysis provides an indication if metals are mobile from the solids, and of potential <br />problem to receiving water systems (such as groundwater or surface water in contact with the solids). <br />TCLP is an aggressive acid digestion process that is commonly used to characterize the 'hazardous' <br />character of a solid waste. It has been deemed inappropriate for use on metal/mining materials since it <br />does not reflect realistic conditions, however it is a conservative method by which to estimate metals <br />mobility. <br />ABA analysis provides an indication if the solids have an acidic character, or a neutral character. The <br />analysis will measure acid generation potential as well as neutralization potential. The net balance will <br />measure whether the material is net neutral, basic or acidic. Forms of sulfur indicate the type of sulfur <br />present in the material. Organic (or residual) is non-reactive while pyritic is. Sulfur as sulfate provides <br />an indication of 'reactive potential' but should be considered a 'bound' form, thus non-reactive. <br />The TCLP results are all below regulatory thresholds. Metals are not being mobilized from the Mountain <br />Top solids. <br />The ABA results indicate that the material is net-neutral, or actually contributes a neutral component <br />and can buffer acid. For instance, refer to the results for Sample 1. Sample 1 has 5 moles of Acid <br />Generation Potential, but when combined with 70 moles of Acid Neutralization potential, the Pile yields <br />a very positive (65 moles) amount of acid base potential (calculated based on sulfur) and also has a <br />neutralization potential attributable to the presence of calcium-carbonate (CaCO3). <br />The forms of sulfur in Mountain top waste rock are in several non-mobile/non-reactive forms (organic <br />and sulfate). Pyritic sulfur is the only type of sulfur to be concerned about, and it is only a small <br />percentage of the total. <br />In summary, the solids material to be explored from the Mountain Top will not likely yield any acid or <br />metals into solution. Therefore, it is unlikely that the portal water quality will be affected by the <br />proposed underground activity. <br />Site Hydrologic Settin <br />The Lower Mountain Top site is located in Lower Governor Basin at an altitude of of approximately <br />11,400 ft in altitude. The basin contains several active mine sites - one with an existing, flowing portal <br />(the Ruby Trust Mine). Above gradient to the Lower Mountain Top is the Upper Governor Basin which <br />contains several historic mine features, all of which contain flowing historic portals (the Humbolt, <br />Revenue/Virginius). These features affect the water quality of the Upper Sneffels Creek drainage which <br />ultimately receives the existing Lower Mountain Portal discharge water as well. <br />M <br />W <br />GO <br />CZ <br />a