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S. Please explain the following discrepancy. On Map 164A, the size of the riprap for the <br /> discharge channel is specified as 4-inch D50. However, in the SEDCAD output report <br /> the D50 values are 6 inches (model for 10-year event) and 9 inches (model for 100-year <br /> event). <br /> Deserado Mine Response: Illustration 61 includes a section titled "Additional Rip Rap <br /> Considerations" and the relevant calculations are included in Appendix D. This same issue <br /> has been raised and discussed previously, most recently with TR-72, and the alternate rip rap <br /> calculations have been accepted by DRMS in the recent past. <br /> 9. Illustration 61 needs to include a discussion of the discharge point from the DW-1 R-Pond <br /> in the context of the CDPS permit for the mine. In particular, will this discharge be an <br /> outfall in the CDPS permit with the Water Quality Control Division (near term or in the <br /> future)? Will it be managed with other dewatering systems to prevent discharge? <br /> Deserado Mine Response: An explanation of the CDPHE WQCD pen-nit status has been <br /> added to the introduction of Illustration 61. <br /> Proposed Revised Pages—TR-73 <br /> 10. Proposed revised page V-24 lists the disturbance associated with the DW-1R dewatering <br /> system to be 0.88 acres. The Division understands that the proposed acreage is to be 0.86 <br /> acres. Please revise Table V-3 on P. V-24 and submit a new copy to the Division. <br /> Deserado Mine Response: These pages have been modified as requested and submitted in <br /> this package. <br /> If you have any further questions please contact me at 970-675-4322. <br /> Sincerely, <br /> Kurtis Blunt <br /> Senior Environmental Engineer <br /> kblunt@deserado.com <br /> enc: <br />