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Mr. C. C. McCall, Director -2- February 2, 1978 <br /> consideration here unless the final grading plan of the aban- <br /> doned tailing area made the surcharge storage large enough <br /> to cause significant property damage, or loss of life, if the <br /> spillway structure failed and produced a flood wave from the <br /> stored water. <br /> 2 . In the reclamation section of the report, it is stated that the <br /> faces of the tailing dams will be covered with a minimum of <br /> 3 feet of "rock waste" from the open pit operation. The <br /> "rock waste" will be placed in benches . <br /> In one part of the report it says that the final overall slope <br /> of the faces will be 2:1 (Robinson No. 1), while in another the <br /> slopes from the benches will be 2:1 with an overall slope of <br /> 3:1 (Mayflower) . The latter statement appears more correct <br /> as the average slope of all the tailing dams is about 3:1 now. <br /> Whatever the case, the stability of the dams with this <br /> added loading, and appropriate phreatic condition, should <br /> be checked for satisfactory safety factors . <br /> Besides the tailing dams , the Climax Mine has four reservoir dams , <br /> which are mentioned in the report, that are under our jurisdiction. They are <br /> Clinton Gulch Dam, Chalk Mountain Dam, Robinson Dam and Climax-Molt' #4 <br /> (Oxide Tailing) . All except Chalk Mountain were built with plans which were <br /> approved by the State Engineer. Enlargement plans have been approved recently <br /> for Chalk Mountain. <br /> Buffehr Lake Dam does not have approved plans , but it is under our <br /> surveillance. Its hazard is very low due to its capacity and relationship to <br /> the Robinson Tailing Dam immediately below it. Climax is carrying out main- <br /> tenance repairs to Buffehr Lake Dam at our request. <br /> All of the reservoir dams have recently been inspected and the files <br /> reviewed by our staff, and appropriate orders 'given for their maintenance. <br /> Climax Mine has complied with our requests in all instances . There are no <br /> current restrictions of storage on the reservoirs by our office for safety reasons . <br /> Finally, we understand that the Climax Mine, through their consultant, <br /> does monitor the tailings dams performance, with the aid of instrumentation, <br /> to ensure their stability. You might request that they furnish you the plan of <br /> this program. <br />