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• ~ ' l;s ~ I ~I ~~ll~ ~ orthwe:t Colorado ~ ultants, Inc. Mai I II I'll l~ ~ 29585 U.S. 40 West, P.O. Box 775226, Steamboat Springs, Colorado 80477 FAX 970-879-7891 // ~ 970-879-7888 R~cEivEo SEP 14 1995 Division o1 M~netais t~ Geology July 24, 1995 Bawer Bros. Conswction 595 Taylor Street Craig, CO 81625 Attn: Mr. Bud Bower Job No. 95-2296 Subject: On-site Inspeuions, Waste Coal Area, Foidel Creek Mine, Routt County, Colorado. Gentlemen, As requested, Northwest Colorado Consultants, Inc. visited the project site on July 6, 7 and 10, 1995 to observe and inspect the tce drain and outlet drain being installed at the north end of [he Coal Waste Pile. The subject projeU is located at the Foidel Creek Mine in Routt County, Colorado. A[ the time of our visit on July 6, 1995, the contractor had completed the excavation of the northern 380 feet of the tce buttress and the fvst 50 feet of the outlet drain. The toe buttress excavation ranged from 40 to 45 feet in width and was excavated into [he underlying shale bedrock materials. The uphill slope of the excavation was conswc[ed [o a 2 (horizontal) : 1(vertical) configuration, as outlined in the project specifications. The outlet drain excavation was approximately 3 1/2 feet wide and 6 feet deep. The contractor had excavated the southern 50 feet of the outlet drain and was is the process of excavating the remainder of the drain a[ the time of our visit. Photographs of the toe buttress and outlet drain excavations (Photos #1 & #2), taken on July 6, 1995, are attached . At the time of our visit on July 7, 1995, the contractor had completed the conswction of the outlet drain from the north end the waste wal pile to the existing drainage situated north of the pile. The outlet drain was approximately 130 fee[ is length, 3 1/2 feet wide and 3 to 4 feet in height. The drain was filled with minus 3/4" washed rock (No. 67 Gradation) and wrapped with a filter material consisting of Trevira 011/140 Spunbound fabric. In addition, they were in the process of conswcting the tce drain at the north end of the pile. The drainage rock was placed is a [riangulaz configuration which ranged from 7 [0 8 feet in width and 32 to 36 inches in height. We advised the contractor that the project plans call for the drain rock to be at least 3 feet in height and recommended that they increase the height of the drain rock ao additional 6 incites. It should be noted that a layer of filter fabric, similar to that destsibed previously, was placed along the ground surface prior to the drain rock placement. Photographs of the outlet drain and tce drain (Photos #3 to #6), taken on July 7, 1995, are attached.