Laserfiche WebLink
'COLORADO <br />Division of Reclamation, <br />Mining and Safety <br />Department c' Na',iru, Resowce> <br />1313 Sherman Street, Room 215 <br />Denver, CO 80203 <br />May 18, 2016 <br />To: Brock Bowles <br />From: Jason Musick <br />RE: New Horizon North Mine, C-2010-089 <br />TR -13, Adequacy Review Memo <br />Per your request, I have reviewed the proposed new NHN-001 Pond East ditch extension associated with <br />the above referenced revision. The review included the proposed designs to determine if the if the <br />demonstrations meet the design criteria for Rules 4.05.3. <br />Based on the Division's review of the proposed NHN-001 East Ditch extension design and the approved as - <br />built NHN-001 East Ditch and as -built Pond NHN-001 designs, the Division has the following adequacy <br />comments: <br />Based on the Division's review of the approved and proposed information pertaining to the Pond <br />NHN-001 East Ditch, the information is not adequate. Although the proposed NHN-001 East Ditch <br />extension provides a design from ditch station 4+88 to 10+79, clarification is requested for ditch <br />segment 0+00 to 4+88. The currently approved east ditch as -built designs are noted for segments <br />27+11 to 0+00 with a cumulative peak flow provided. Proposed Page 3 of Section 2.05.3(4) states <br />that Appendix 2.05.3(4)-1 contains ditch design information for the NHN-001 East Ditch from <br />station 0+00 to 4+88 as shown on Map 2.05.3(4)-11. However, Appendix 2.05.3(4)-1 only includes <br />a "typical" ditch design for the east ditch prior to construction and the submitted as -built design <br />identified in appendix 2.05.3(4)-7. In addition, proposed page 3 of proposed appendix 2.05.3(4)- <br />11 states the the new stationing, starting at 0+00 to 10+79 represents the area not previously <br />described in Section 2.05.3(4). Also, the proposed Map 2.05.3(4)11 identifies station 0+00 to 4+88 <br />as "existing ditch." <br />Based on the above information, the Division believes that the design criteria required under <br />Rule 4.05.3 for the east ditch is inadequate for the entire east ditch existing or proposed. Please <br />provide information concerning the design of the the NHN-001 east ditch from station 0+00 to <br />4+88, or provide justification as to the omission of the design criteria for this segment of the <br />east ditch for review by the Division. <br />1313 Sherman Street, Room 215, Denver, CO 80203 P 303.866.3567 F 303.832.8106 http://mining.state.co.us I <br />John W. Hickenlooper, Governor I Mike King, Executive Director I Virginia Brannon, Director <br />