INSPEC11889 - Laserfiche WebLink

Home Browse Search

MINE SITE INSPECTION NARRATIVE 2 Mr. Price said that the company has modified their original design for drainage on the area by requesting for approval to let a gully form on the western perimeter of the mine. Most of it was snow covered during the inspection but from information in the mine plan, it appears to run parallel with the one of the access roads left on the mine. Apparently, several rills formed during the spring runoff season of 1989. At that time it was identified in their rill and gully plan and managed according to the requirements approved in the plan. Since that time, the operator requested approval to reshape the drainage in the area by combining the rills, they centralized it into a gully. Approval of the feature required studies of surrounding terrain, that data was submitted in 1990. Walden Coal indicated in their TR request approved by the division July 26, 1990, that the formation of a permanent gully across the Bourg property as proposed is a realistic long term approach to controlling erosion along the drainage. The gully apparently remained stable through the 1990 runoff season. The gully will be managed according to the rill & gully reclamation plan. The gully has been graded, rip-rap has been added, and the area has been reseeded. The criteria for retaining the gully is based on studies of surrounding like terrain with the erosion in the gully on the mine being normal. Apparently work will be implemented on the gully if the determination is made that erosion is excessive in nature. I did not address this approval in any detail on this inspection. The grading plan on this mine is unlike any other because there is an approval for no sediment ponds during the interiem following reclamation planting where runoff water quality equals out of mine, similar drainage runoff water quality. This in and of itself is approved on the basis of computer modeling. I would have to assume that the gully formation and approval therof is tied in with this plan. That being the case, I feel that a closer review of this approval would be futile. I would however, question how phase III approval for bond release will be initiated without evidence of runoff sampling from the disturbed area. It would seem that gully formation would result in sediment loss, did this occur under storm conditions exceeding the design criteria for the mine drainage. In turn is loss under normal years from this gully part of the computer design approval ? The two remaining alluvial ground water monitoring stations on the mine in Mann Draw were noted during the inspection. They appeared to be in good repair. Surface water monitoring which included NPDES requirements is no longer required on the mine. The 4.5 acre loadout for the mine located a few miles north of Cowdrey, Colorado was also inspected. It too was snow covered. The area is fenced, signs are posted meeting permit requirements. No apparent drainage control problems were noted. The loadout is located next to a railroad siding is still in place. The mine permit, C-81-021, expires April 21, 1993.