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v' <br />is unorthodox and deserves discussion as to how it is accomplished <br />while maintaining such parameters as pH, water temperature, <br />reagent oxidation rates, etc. within limits consistent with good <br />resource recovery. <br />The milling circuit shown in the diagram does not correspond with <br />what is curtently possible at this facility. The thickener tank is <br />completely full of solids and has been for months. Clearly, some <br />other process has been in use than that shown; it should be <br />described and appropriately diagrammed. Alternatively, a plan for <br />removal and disposal of the solids in the thickener tank should be <br />identified, together with the requisite engineering. <br />Operating history at this facility has included a number of tailings <br />spills, some of which were accompanied by loss of containment <br />from within the milling facility itself. A plan must be identified <br />which will, when fully implemented, preclude such containment <br />losses, whether from within the mill or from the tailings <br />impoundment. At a minimum, engineering must include design <br />features to insure containment of the maximum probable spill <br />within the mill building and adequate freeboard in the tailings <br />pond. Operating procedures must be defined which will assure <br />operation of all facilities within design limits. Verification <br />procedures must be written and adhered to. Warning devices such <br />as liquid-level indicators, flow-rate indicators, water temperature <br />indicators, etc. are required to identify incipient off-nominal <br />conditions in time to allow operating personnel to correct the <br />condition or shut down the operation prior to the occurrence of loss <br />of containment. <br />(d) Exhibit D -Reclamation Plan: It is important to state explicitly <br />that we do not wish to recede in any way from the reclamation <br />philosophy adopted in the I98S Cash Mine amendment already <br />referred to. A specific problem we see with the present proposal <br />is the use of liming agents during the reclamation operations. A <br />letter from MLRD to M. Steen dated September 16, 1985 <br />(referenced above) raises serious concerns about the suitability of <br />liming for reclamation purposes. Mr. Steen's reply of September <br />23, 1985 (referenced above) was generally acceptable to us then, <br />and remains so now. Some specific details discussed in that letter <br />require further thought, but the broad thrust of the reply is <br />appropriate. <br />1 <br />