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9/30/93 <br />Responses to Comments <br />San Luis Reclamation Evaluation Report <br />Page 21 <br />As discussed in the report and in previous responses <br />in this document, BMRI believes that collection of <br />pore water samples is extremely difficult if not <br />impossible due to the impermeable, compacted nature <br />of the tailings material. Also, as discussed in the <br />text of the report (pg 35), BMRI believes that <br />collection of the sample utilizing some type of pore <br />vacuum system may not yield reliable or usable <br />results even if such a sample could be collected. <br />This is especially true for the reliability of <br />cyanide numbers. <br />As discussed in the preamble, BMRI has collected <br />additional samples to verify that the mriginal <br />program adequately characterized the tr.ailings <br />material. Although, as discussed above, BMRI is <br />highly skeptical that valid pore water samples can <br />be obtained, BMRI has obtained samples of tlhe pore <br />water and will analyze these samples for cya~hide and <br />metals. <br />Comment: <br />Appendix, leach Tests, A. The accelerated weathering test <br />employed to simulate weathering of the Battle Mountain <br />Tailings, both in the original permit and in the res nse to <br />Abatement Item 1~8, seems not to account as well as poss~ble for <br />the conditions that will exist at the site. Although I believe <br />it is appropriate to use simulated rainwater as the leschate, <br />I believe also that the acids produced as a product of the <br />first weathering cycle should be recycled back iato the <br />tailings as other rainwater is added. <br />Response: As discussed in a previous response, the accelerated <br />weathering tests have accurately predicted acid <br />generation in 100$ of the tailings sampled in a <br />study performed by the Canadian government. <br />Simulated rainwater is used to predict the effects <br />of the natural precipitation conditions on the <br />tailings material. The second part of this <br />statement is unclear. It implies that the DMG <br />believes that there were acids produced as part of <br />the San Luis humidity cell testing. This is not the <br />case. <br />As discussed in Section 4 of the Preamble, recycling <br />of the liquid obtained from each cycle does not <br />occur for two reasons. First, because this does not <br />