Laserfiche WebLink
Mr. Tom Kaldenbach <br />March 8. 2013 <br />Page 4 <br />Other than the dissolution of metal oxides in the mine wall rock, which will be <br />addressed through pre - filtration processes in the RO treatment plant, there is no <br />expected effect of organic carbon on the R() treatment process. As noted in response <br />"d" above, the organic carbon will increase the density of the RO Slurry and hasten <br />the deposition of the beneficial carbon source at the bottom of the mine pool. <br />28. (This comment is intended to address comment -1 from 1)RMS 's August 29 letter.) Please <br />provide a printout of results of model projections for the RO system. <br />Attachment 2 to this letter is a printout of the 'foray industries. inc. modeled results of <br />specified RO treatment on Schwartzwalder mine water. Specifically, Item 3, on page two <br />shows constituent concentrations in the mine water (feed) and the resultant concentrations <br />post treatment in both the RO Retentate and the RO product or permeate. <br />29. (This comment is intended to address comment 5 from I)RMS'sAugust 29 letter.) Please <br />provide a contingency plan for disposing RO residuals outside the mine pool, should pilot - <br />scale testing or full -scale testing indicate returning the residuals to the mine pool is not <br />Jeasrhle <br />Returning RO residuals to the mine pool, incorporated in backfill slurry, under a UIC permit <br />by rule" is not onl\ feasible but desirable. <br />Further. Cotter is not convinced a feasible off -site option exists. File RO Retentate prior to <br />barium chloride addition will be water with dissolved constituents present, including sulfates, <br />manganese, uranium, radium and molybdenum. Cotter is not aware of commercial off -site <br />disposal options for such a mixture of materials. Cotter has previously evaluated on -site <br />storage in ponds with water content reduced via evaporation. However, it is neither certain <br />that regulatory approval for such an undertaking can be achieved from the multiple agencies <br />involved nor that the placement of ponds is achievable considering site geography. <br />30. Please describe four involvement with EPA regarding the UIC permitting requirements <br />for the work proposed in your submittal. <br />Cotter is working closet? with EPA regarding the [IC permitting framework and <br />requirements. It has provided additional information to [PA in response to an EPA request <br />for information. <br />31. Please provide a contingency plan and schedule for a scenario in which (IIC permitting <br />cannot he completed in time for meeting the schedule shown in Figure 3. <br />In the event that an extension of the March 31. 2013 date in the September 18. 2012 Mined <br />Land Reclamation Board ( "MLRB " ") Order is needed. Cotter will pursue such an extension at <br />the March 2013 MLRB meeting. <br />32. Please commit to having the installation of the well in the south waste rock pile overseen <br />by a knowledgeable a trained hydro - geologist geologist, and also commit to utilizing <br />experienced personnel ,tor correctly installing the well. <br />