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Geotechnicel t EnviTemental Engi(krkp Materiels Testing <br />Celebrating-9 <br />sl <br />Ladies and Gentlemen, <br />fte <br />Subject: Construction Recommendations, Pond 016 <br />Area Slides, Seneca 11W Mine, Routt County, <br />Colorado. <br />June 7, 2012 <br />Seneca Coal Company <br />P.O. Box 670 <br />Hayden, CO 81639 <br />Attn: Roy Karo <br />Job Number: 08 -8099 <br />As requested by our client, Seneca Coal Company (Seneca), NWCC, Inc. (NWCC) has been providing the construction <br />quality control (materials) testing and site observations required during construction of remediation efforts conducted <br />to stabilize and dewater the landslide areas located upslope of Pond 016 and Pond 016A, as well as the landslide area <br />downslope of the Shrub Plot. NWCC hag been providing the construction observation and materials testing services on <br />a part -time basis from August 30, 2011 tp May 16, 2012. NWCC conducted over 25 visits to the site during this time <br />period. <br />Based on our observations and compac on test results, it is NWCC's opinion that the construction/remediation has <br />been completed by the client in general formance with the Pond 016 Area Remediation Plans dated October 2010, <br />and the recommendations provided in the Geotechnical Evaluation and Stabilization/Reconstruction Recommendations <br />report previously prepared by NWCC for the Pond 16 Landslide and dated August 3, 2009. <br />Based on the amount of stabilization wok that has been completed since last August and the fact that the runoff from <br />this past spring has been at record lows, CC strongly recommends the placement of topsoil and seeding be delayed <br />until next year. Even though there was o indication of new slope movement in the repaired areas this spring, NWCC <br />recommends that the site be allowed experience one more runoff season to ensure that the stabilization and <br />dewatering work completed to date are nctioning adequately under normal seasonal runoff conditions. <br />(970) 879 -7888 • Fax (970) 879 -7891 <br />2580 Copper 'dge Drive • Steamboat Springs, CO 80487 <br />