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7 . The Division has approved two permanent diversions of Coal <br /> Creek, one of which has been constructed to date. The Division is <br /> concerned with the performance of the rip-rap "footers" used to <br /> stairstep the diverted channel segment. The footers were designed <br /> to pass' the 10 year/24 hour event without erosion, but they have <br /> frequently washed out and required repair in the one reconstructed <br /> channel segment which has been completed. Rule 4 .05. 4(2) (a) allows <br /> for the use of artificial control structures in permanent <br /> diversions "only where they are stable and will require infrequent <br /> maintenance. " In consideration of the observed performance of the <br /> reconstructed channel segment and the riprap footers, the operator <br /> should submit revised permanent channel erosion control designs <br /> which will meet the requirements of Rules 4 .05 . 4( 2 ) (a) and (b) , and <br /> 4 . 05. 4(4 ) . <br /> 8 . The Coal Creek stream channel permanent diversion referenced <br /> above, as well as the South Diversion Ditch above the Roadside <br /> Refuse Pile, and the Permanent Diversion Ditches above CRDA #2 are <br /> subject to the construction certification requirement of 4 . 05.4(2) . <br /> See also Rule 4 . 09 . 2( 7) for the refuse area permanent diversions. <br /> Construction certifications for these diversions cannot be located. <br /> Please provide copies of the required certifications. <br /> 2 . 05. 3(6) . 2.05. 3 ( 8) . 2.05.4(2) (a) . and 2.05.4(2) (c) <br /> 1 . Discussion of reclamation status of the North Decline and the <br /> Northwest Intake on Page 186a should be updated to reflect current <br /> status. Also, the discussion of contemporaneous refuse pile <br /> reclamation should be broadened to clarify that it applies in <br /> general to reclamation at CRDA No. l , No. 2 , and No. 3 , and not just <br /> the lower benches of CRDA No. l and No. 2 . <br /> 2 . On Page 186 it is stated that final reclamation of the Roadside <br /> Refuse Pile will occur at the end of the mine life when the top of <br /> the pile is no longer needed for storage and benches can be graded <br /> on the outslope to reduce erosion. Additional detail will need to <br /> be provided regarding the reclamation sequence and final <br /> configuration of the Roadside refuse pile, including the slope of <br /> the top of the pile, bench dimensions, spacing, and slope. It is <br /> assumed that existing soil cover on the pile will need to be <br /> removed and stockpiled to allow for final grading and bench <br /> construction. The Post Mining Contour Map, Exhibit 6C, should be <br /> modified to include the erosion control benches, along with <br /> permanent drainage features including the South Diversion Ditch, <br /> and other diversions associated with the final refuse pile <br /> configuration. Representative final refuse pile cross-sections <br /> should be provided. <br /> 3 . The reclamation cost estimate for the Roadside South Portal <br /> area includes an assumption that 93 ,000 LCY of borrow material <br /> would be imported for use in reclamation of the mine bench and <br /> refuse area. It is not evident from the limited cross-sections and <br />