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The results of these types of tests were evaluated to <br />determine if the tailings and waste rock could be reprocessed. <br />These tests included: <br />o Tests on characterizing the waste rock with respect to <br />particle size distribution and selected contaminant <br />concentrations (copper, zinc, lead, chromium, and arsenic), <br />total sulfur, and precious metals (silver and gold) in <br />different size fractions; <br />o Froth flotation tests for recovery of an economic product; <br />and <br />o Leaching tests on waste rock and new tailings to determine <br />potential environmental impacts. <br />Results of the tests indicate that the quantities of <br />contaminants remaining in the new waste tailings were <br />significantly reduced. However, leachate concentrations were <br />greater than AWQC for selected contaminants such as.zinc. <br />Reprocessing would be a permanent solution that eliminated <br />Collapse of the tailings and waste rock piles. A new waste <br />tailings is produced. Leaching tests show that the new tailings <br />can be disposed in a municipal landfill. <br />Comparison of Alternatives <br />Listed in Table 2, in matrix format, are the key criteria <br />considered in evaluating and comparing alternatives. These <br />criteria are specified in J. Winston Porter's memorandum <br />"Additional Interim Guidance for FY '$7 Records of Decision," <br />dated July 21, 1987 and include: <br />o Protection of human health and the environment <br />o Compliance with legally applicable and/or relevant and <br />appropriate requirements <br />o Reduction of mobility, toxicity or volume <br />o Short -term effectiveness <br />o Long -term effectiveness and permanence <br />o Implementability <br />o Cost <br />o Community acceptance <br />o state acceptance <br />23 <br />