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(Page 2) NINE ID ~ OR PROSPECTING ID ~ M-79-214HR INSPECTION DATE 3/2/95 INSPECTOR'S INITIALS CSC OBSERVATIONS This inspection was conducted to determine if the current bond of 540,000.00 is sufficient to complete reclamation and to assess the stability of the quarry. Ms. Julie Goettemoeller and Mr. John Hickman were present for the operator. The weather was overcast and snowing and the ground was covered with a few inches of snow. A follow-up inspection may be conducted in the future during more favorable weather conditions. This is a drill and shoot, hardrock quarry permitted for 75 acres. The current maximum affected acreage is 20 acres, which presently is the approximate size of the operation. The disturbance is situated on steeply sloping ridges along the north and south sides of Wildcat Gulch, an ephemeral tributary of Deer Creek. The rock consists of dark colored pre-Cambrian gneiss and schist with occasional pink colored migmatite dikes composed of feldspar and quartz. Blasted rock is loosely piled at the top of the quarry on the west end. Downhill, are 5 major benches arranged like stair-steps with the highest bench situated at an approximate elevation of 6,800 feet amsl on the west and the lowest bench to the east at an approximate elevation of 6,300 to 6,400 feet amsl. There is about 600 feet of total relief between the quarry entrance and the rock pile on the west end. About 40,000 to 50,000 cu. yds. of topsoil is stockpiled in a wedge shaped pile along the northwestern side of the quarry within Wildcat Culch. This location is not shown on existing mining plan maps of the operation. The top of the pile slopes at approximately 3:1 to the east. Even though the stockpile has been seeded with grasses, some initial erosion rills were observed on the lower, eastern portions of this slope. The location of the topsoil stockpile and the measures used to stabilize it from erosion and runoff need to be submitted to the Division in the form of a revision to the permit. (See PB-1). Any stormwater or erosion coot rol measures which will require a bond for reclamation need to be included in the revision or the Division must be notified that no measures requiring a bond will be used. Besides the topsoil stockpile, the haul road and portions of some benches also appear to be constructed in fill emplaced within Wildcat Gulch. According to the permit application and subsequent responses, filter rock creek drains were installed in Wildcat Gulch to prevent sediment from entering the drainage. Due to the snow cover, these. features were not observed. The permit also discussed a 4' high x 10' thick seepage check dam and sediment pond which is used to control erosion and runoff from the mining operation. Thin also was not observed in the field. The Division did not see a copy of the engineering details in the file for rock drains and did not see a copy of the Stormwater Management Plan for this operation. The Division infers that the filter rock creek drains were installed to protect the topsoil pile and any other material stockpiled or constructed in wildcat Gulch from runoff. If these are included in the erosion and runoff control measures for this operation, the operator needs to submit a runoff analysis to include peak discharge through the disturbed area and the flow capacity of the filter rock drain to the Division. The mining plan for this operation includes a typical bench detail with 20' wide benches and 40' highwalls with a .25:1 slope. During the inspection, the heights of the highwalls were estimated using a clinometer and they were visually inspected for obvious signs of instability. Although they appeared on the most part to be stable, three areas of loose and fractured rock were observed in the highwalls. The height of each highwall was estimated starting at the highest point in the quarry (at the west end) and working towards the lowest (in elevation) benches. The following heights were measured: 42', 60', 66', 61-84' and 44- 63'. The Division has safety and stability concerns since some of the highwalls exceed 40' in height. The operator will need to bring the highwalls which exceed the approved mining plan height into compliance with the plan or change the mining plan in a revision to the permit to include the existing highwall conditions. To change the plan, the operator must demonstrate that the existing highwalls are stable. (See PB-2).