REV88434 - Laserfiche WebLink

Home Browse Search

~ ~ iii iiiiiiiiiiiu iii STATE OF COLORADO DIVISION OF MINERALS AND GEOLOGY Deparimenl of Natural Resources 131 3 Sherman Si., Room 215 Denver, Colorado 80203 Phune: (3031 866-3567 FAk. f30A 83?-8106 June 6, 1994 TO: Wally Erickson FROM: Tony Waldron ~~ . ~~~ DEPARTMENT OF NATURAL RESOURCES Memo Roy Romer Governor Ken Salazar Eaec un ve Dneaor \ nachae~e. Long Drv~sron Direanr RE: Rimrock Coal Mine, C-89-074, Technical Revision-09 Per your request and per our site visit to Rimrock Coal Mine, I have reviewed Rimrock's request to reduce their topsoil replacement depth from the previously agreed upon depth of 15 inches to 11 inches. My concerns are outlined below. My understanding of the reclamation plan is that excess topsoil would be salvaged in phase I of the plan to make up for a anticipated shortfall of topsoil during phase II of the operation. Apparently, not even enough topsoil was salvaged during phase I to adequately replace topsoil to a depth of 15 inches in the phase I disturbed area. This in itself is quite disturbing because what it says is that the operator did not salvage the proper depth of topsoil at the very beginning of the mining process. It is possible that the mining did not progress to the point that abundant reserves of topsoil were available during phase one, thereby accounting for the apparent shortfall of topsoil to meet the 15 inch reapplication requirement. Another possibility is that the qualified personnel or the Division were not on site to verify the topsoil stripping depth. Whatever the case the operator has not verified that this is what occurred, thereby causing the shortfall of topsoil to be available for reclamation. whatever happened is history now and it is very apparent that there is not enough topsoil to meet the 15 inch replacement requirement. This was verified through field investigations conducted by the Division, as I understand it. With that in mind 11 inches should be adequate to meet their reclamation objectives and postmining landuse of rangeland, however based on our site inspection I do not believe there is even 11 inches of topsoil over the entire reclaimed site and that is a cause for concern. As you may recall we walked the regraded area because you had some questions about the rills and gullies that were forming over the southern end of the property. As we walked across the regraded area from north to south it was fairly obvious where the operator had replaced topsoil on the northern end of the regraded area. However,