Laserfiche WebLink
STATE OF COLORADO <br />DIVISION OF RECLAMATION, MINING AND SAFETY <br />Department of Natural Resources <br />1313 Sherman St., Room 215 <br />Denver, Colorado 80203 <br />Phone: (303) 866-3567 <br />FAX: (303) 832-8106 <br />4 February 2009 <br />Ms. Jennifer Sekulski <br />Colowyo Coal Company, LP <br />5731 State Highway 13 <br />Meeker, CO 81641 <br />Re: Colowyo Mine C-1981-019 <br />Preliminary Adequacy Review - Technical Revision 78 <br />Dear Ms. Sekulski: <br />COLORADO <br />D I V I S ION O F <br />RECLAMATION <br />MINING <br />SAFETY <br />Bill Ritter, Jr. <br />Governor <br />Harris D. Sherman <br />Executive Director <br />Ronald W. Cattany <br />Division Director <br />Natural Resource Trustee <br />The Division has received Colowyo's submittal of Technical Revision 78. The revision <br />was received on 24 December 2008 and deemed complete on 5 January2009. The <br />Division has reviewed the submittal and has the following comments and questions. <br />General Comments <br />The cover letter submitted with Technical Revision 78 states "The purpose of this <br />revision is to comply with part five of NOV CV-2008-004 abatement to submit a <br />complete Technical Revision to the Division detailing methods that will be immediately <br />implemented in the Prospect watershed to reduce the peak flow to the Prospect Pond." <br />Colowyo will also be submitting another revision by 31 March 2009 regarding additional <br />reclamation practices and sediment control measures to be implemented in the Prospect <br />watershed. The future revision will propose important reclamation practices and <br />sediment control measures to be implemented in the Prospect watershed during the period <br />that Colowyo will use the internal ditches and temporary sump, as well as long-term <br />measures to be taken to reduce runoff volume and limit peak flows to Prospect pond. <br />TR-78 addresses temporary measures to reduce the peak flow going into Prospect Pond. <br />Design criteria and SEDCAD modeling for sediment control structures, specifically a <br />temporary sump and three temporary ditches, in the Prospect Drainage section in the East <br />Pit reclamation area are included in the application. The Division has no concerns with <br />the SEDCAD modeling runs for the three internal ditches as proposed. Input used for the <br />erodible particle size is consistent with a soil fitting a texture classification of a loam/silt <br />loam and would likely be representative of spoil areas with moderate amounts of clay and <br />Office of Office of <br />Mined Land Reclamation Denver • Grand Junction • Durango Active and Inactive Mines