Laserfiche WebLink
III IIIIIIIIIIIII III <br />MINED LAND RECLAMATION DIVISION <br />Department of Natural Resources <br />13t3 Sherman St., Room 2t5 <br />Denver, CO 80203 <br />303 8663567 <br />Fa x: 303 832~8t06 <br />STATE OF COLORADO <br />OF'~~lp <br />Ne <br />. ~H,^,. <br />~ /9~6 <br />Roy Romer, <br />Governor <br />April 17, 1991 <br />Mr. Gary Wendt <br />Peabody Coal Company <br />Western Division <br />1300 South Yale <br />Flagstaff, Arizona 86001 <br />RE: Seneca II-W, TR No. 12 <br />File: C-82-057 <br />Dear Mr. Wendt: <br />Fred R. Banta. <br />Division Director <br />The Division has reviewed the ditch design information submitted as TR-12 as <br />partial abatement of NOV C-91-001, We have the following comments: <br />1. EXHIBIT 12-9-4 shows the riprap portion of the ditch to be the <br />portion labeled as TAHRD-9A. However, in the narrative page 2, <br />section "b" the operator states that all portions of the ditch <br />exceeding 5% slope will be riprapped. The EXHIBIT should reflect <br />what is in the narrative. On TABLE 12-5-A the slope given for <br />TAHRD-9R (80%1 is in error and should be changed to reflect the <br />actual slope (8%l. <br />2. It has been the Division's experience in the past that triangular <br />riprap designs with slopes exceeding 5% do not work very well, The <br />Division would like to suggest that the operator consider a <br />riprapped trapezoidal ditch with a minimum of 3 feet bottom width <br />properly lined with gravel sub-base or other non-erodible material <br />before properly placing the riprap. <br />Please contact Berhan Keffelew or me if you <br />Since <br />1 <br />Dan T. Mathews <br />Reclamation Specialist <br />DTM/yjb <br />CC: Berhan Keffelew <br />have any questions. <br /> <br />4956E <br />