2012-11-13_REVISION - C1981019 (2)

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November 9, 2012 COAL ic .YCOMPANY o4 .pgo raoaocr1O$ 5731 State Highway 13 • Meeker, Colorado 81641 Mr. Rob Zuber Environmental Protection Specialist Colorado Division of Reclamation, Mining and Safety Department of Natural Resources 1313 Sherman Street, Room 215 Denver, CO 80203 • 970- 824 -1500 RECEIVED NOV 1 3 2012 Division of Reclamation, Mining & Safety RE: Colowyo Coal Mine, Permit C- 1981 -019, Bond Release Application No. 6 (SL -06), Adequacy Review Response Dear Mr. Zuber, Colowyo received comments in regards to SL -06 from the Colorado Division of Reclamation Mining and Safety (Division) on September 7, 2012. Colowyo has the following responses to the Division's comments: • In the North Tributary of the East Pit Ditch there is a bare spot below the NTEP Pond. This reach of the channel should have riprap armoring per the design in the PAP. However, there is no erosion in the channel. Response: This is Structure No. 8 in the SEDCAD Model. This segment has been re- evaluated and modeled as a vegetative lined channel. It was found to have acceptable peak velocity (4.99 fps) for a vegetative lined channel. Refer to the attached SEDCAD output "NTEPD 1024 2017', and follow the model to Structure No. 8. A grass lined channel will suffice for this section of ditch. • In Prospect Ditch, in the reach between the ponds, the channel is not well shaped and is eroded. Below the lower pond (PD1) riprap is sparse in some areas. Response: The reach in between the ponds (vegetated channel not riprap lined) was re- shaped and re- seeded accordingly. No additional work or response is necessary. The lower reach below PD1 is Structure No. 32 in the SEDCAD Model. This segment has been re- evaluated and modeled as a vegetative lined channel. It was found to have acceptable peak velocity (2.12 fps) for a vegetative lined channel. Refer to the attached SEDCAD output "Prospect A Western Fuels - Colorado, LL(. ruining property