Laserfiche WebLink
5: 1 <br />Mr. Edgar Hunter 10 November 19, 1992 <br />The applicant's discussion of this methodology (Exhibit E - IV -Rinsing with <br />hydrogen peroxide) states that it would be impractical and uneconomical to <br />begin neutralization at this cyanide concentration (150 ppml. It is further <br />stated that the concentration can be reduced by recirculating process water <br />without chemical additions and to "rest" the heap during the winter months. <br />Using this process how long will it take to bring the cyanide concentration <br />down from 150 ppm to 25 ppm? What will be the cost of pumping? What <br />are the costs involved in setting up a hydrogen peroxide delivery system? <br />How much HzOz will be needed and what are those costs? <br />In addition to the beginning 21,000,000 gallons of working solution how <br />much make-up water would b8 needed during this process, and how much <br />more make-up water would be needed before a 0.2 mg/1 concentration <br />would be reached? <br />7. Section IVlf) of Exhibit E -Reclamation Plan states that all (leach padl slopes <br />will be left in a stable configuration, rounded to conform with existing <br />topography and seeded after proper preparation. Please be more specific as <br />follows: <br />a. What will the slopes be? What criteria is used to determine a stable <br />slope? <br />b. What standards will be used to determine if the slopes "conform with <br />existing topography"7 A contour map with 5 or 10 toot interval <br />contour lines would be helpful to determine what the final slopes will <br />look like. <br />c. Please describe what "proper preparation" of the slope will include. <br />8. As previously discussed in Section III - C of this review, the operator must <br />commit to specific seed mixtures and fertilizer and mulch rates. Topsoil <br />replacement depths should also be committed to. The number of trees and <br />shrubs planted should be increased to 200 seedlings/acre. <br />XVI. Facilities <br />Previous comments regarding commitments to topsail depths, seed mixes, <br />fertilizer and mulch rates, soil island locations and tree and shrub numbers <br />also apply to this area. <br />2. Reclamation is based on "worst case" conditions, i.e. no additional <br />operations by the applicant; therefore, a reclamation plan is needed for the <br />Carlton Mill building. <br />