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INSPECTION REPORT - PAGE 2 FILE N0. M-84-041 DATE: April 5, 1984 The primary purpose of this inspection was to visit the proposed mine site to evaluate potential effects of mining and possible mitigative measures prior to permit approval. This inspection was conducted ,jointly with Bureau of Land Management representatives: j2z,4~Atkins and Mtke McGuire in order to facilitate coordination of our reclamation requirements. OBSERVATIONS OF IMPORTANCE: 1. The proposed permit area is approximately 1 mile north of the Gypsum exit off of Interstate I-70. The proposed permit area is approximately 32 acres in size; of which 12 acres will be affected to the first stage. 2. The 72 acre area proposed for the first stage of mining encompasses one ephemeral drainage area. The point of drainage concentration 1s located where a culvert passes beneath the county road. The facilities, including a crusher, and sedimetnation pond will be located at the base of the drainage area adjacent to the County Road. Mr. Tingley stated that, "the sedimentation pond will be approximately 60,000 gallons in size utilizing the existing culvert under the county road as a discharging device". Currently, this culvert inlet is completely covered with silt. 3. The permit application stated that, "no topsoil existed on the site". However, while visiting the site we observed that on the ridge side topsoil was in existance. It was approximately 2 inches to the A horizon and 4 additional inches to the 8 horizon. Within the drainage channel the topsoil exceeded two feet in depth. 4. Vegetative cover was dominated by shrubs; big sagebrush, rabbitbrush, winterfat and some greasewood. The primary grass was Indian ricegrass and there was a small prostrate forb which looked/a buckwheat. 1~, RECOMMENDATIONS: 1. The proposed post-mining topography of 2:1 may not be stable. On site we discussed possible methodologies for stabilization of the post-mining slopes. One suggestion was utilization of benches on the reclaimed slope which would also increase revegetation potential. 2. The second item of concern was the sizing of the sedimentation pond. The area proposed for the sedimentation pond is very small. Also the mining activity will increase the drainage area. The existing situation of complete blockage of the culvert shows that the culvert under the County Road was insufficiently sized. A hydrologist from the BLM will go out on site to evaluate the appropriate sizing for the sedimentation pond.