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ort <br />Geotechnical / Environmental Engineering • Materials Testing <br />October 9, 2018 <br />Twentymile Coal Company <br />Jerry Nettleton <br />29515 RCR 927 <br />Oak Creek, CO 80467 <br />Job Number: 99-3983 <br />Subject: Quarterly Observation Report, Refuse <br />Pile, Foidel Creek Mine, Routt County, Colorado. <br />Mr, Nettleton, <br />As requested, NWCC, Inc. (NWCC) has prepared this report outlining our observations made during the <br />third quarter of 2018 at the Refuse Pile located at Twentymile Coal Company's (TCC) Foidel Creek Mine <br />in Routt County, Colorado. During this quarter, Timothy Travis of NWCC visited the project site on <br />September 28, 2018 to provide the quarterly inspection/observations of the Refuse Pile. <br />At the time of our site visit on September 28, 2018, NWCC completed a site inspection of the existing <br />refuse pile. Based on our observations made during this visit, it appeared that the contractor was presently <br />stockpiling and compacting refuse coal in the new Expansion Area. At the time of our site visit the refuse <br />coal had been placed and compacted to an elevation above the second bench situated along the east side of <br />the stockpile. <br />In addition, a representative of NWCC visited the refuse pile on September 13, 2018 to conduct compaction <br />testing in the new Expansion Area of the refuse pile. Three compaction tests (#569 to #571) were taken in <br />Expansion Area during this quarter. All of the tests taken during this quarter met the minimum compaction <br />requirement of 90% of the maximum standard Proctor density. Copies of the compaction test results and <br />the daily field reports are attached. It should be noted that the abbreviations given in the Nuclear Density <br />Test Results (Proctor Data) are as follows: Maximum DD = Maximum Dry Density and OMC = Optimum <br />Moisture Content. Both of these values have been determined in accordance with ASTM D698. <br />The internal roadways in the new expansion area of the pile are in good condition. The upper haul road to <br />Areas 2, 3 and 4 of the refuse pile was accessible at the time of our site visit and in good condition. <br />A seepage area at the toe of the northeast end of the refuse pile expansion area, approximately 30 feet <br />northwest of the outlet of the underdrain, developed in fall 2014. At the time of our observations, the <br />seepage was surfacing at the toe of the slope and flowing into the drainage from the undrain outlet then into <br />the existing pond east of the Refuse Pile Expansion Area. The discharge was clear, with no evidence of <br />sediment. No signs of washout, slumps or slope instability were observed at this time. The seepage area <br />(970) 879-7888 • Fax (970) 879-7891 <br />2580 Copper Ridge Drive • Steamboat Springs, CO 80487 <br />