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February 4, 2009 <br />Pg. 4 <br />• Pg. 14: How certain are you of the integrity of the Deadman Gulch synthetic liner? Has the <br />discharge rate in Deadman Gulch been measured at various points along its length to determine <br />if the liner is intact? <br />Pg. 15: In reference to the statement "... results of the alluvium mineral content indicate that <br />this pathway has not occurred" is there evidence of a geochemical boundary of some sort, such <br />as a redox boundary, that might cause metals enrichment at depth? If not, why is it not <br />plausible that dissolved metals could be transported through the alluvium to a possible release <br />point at the seep if Eh-pH conditions remain constant along the flowpath? <br />• Pg. 16: Please describe what testing or analytical methods were used to determine that divalent <br />metals had or had not been solubilized from the rock. <br />• Pg. 16: Please describe, preferably via chemical reaction equations, the process whereby <br />"divalent metals should solubilize from the solids (and) would lend acidic character which in <br />turn would solubilize certain minerals." <br />• The report refers to soluble sulfur. What are the forms of soluble sulfur that have been <br />identified? <br />• Please describe the forms of soluble and insoluble aluminum, iron, lead, manganese, and zinc <br />that are referred to. <br />• The use of non-conservative ions (Al, Cd, Cu, Mn, Zn) as ground-water tracers or indicators is <br />questionable. The solubility and speciation of Al is strongly pH-dependent regardless of source <br />rock, Cu and Mn are redox dependent, and all of these will vary with pH due to surface <br />complexation. The reason that the concentration of dissolved aluminum in well B is greater <br />than in well C may simply be because the pH of Well B is nearly one full unit lower than well C <br />(4.7 vs 5.5). At pH < 6, total Al solubility increases 1-2 orders of magnitude for each unit <br />decrease in pH. With respect to generalizations regarding metals concentrations, the same <br />argument holds for comparison of alluvial water (pH = 4.x to 5.x in Well B and Well C) versus <br />toe seep water (pH = 3.7 to 3.87). Please provide a valid rationale for using these non- <br />conservative ions as tracers and indicators. <br />• The working hypothesis appears to favor a source with a recharge area potentially distal from <br />the discharge area (seeps), a scenario which lends itself to the use of isotopic analyses. The <br />2,500 ft of relief between the Level 6 adit and the ridge crest indicates favorable conditions for <br />oxygen and deuterium fractionation [ridgetop 12,740; GW 10,240; valley floor 8,800]. Has this <br />option been considered? <br />• Little information is provided on the configuration of the local and regional potentiometric <br />surface; such information might be very useful in validating the Operator's argument regarding <br />the source(s) of the waste rock toe seep. Are there any additional data on the local and regional <br />potentiometric surface?