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• Summary of Armstrong Engineers' Report <br />The report by Armstrong presents the results of their studies and design <br />for the reject pile. A reject pile height of approximately 230 feet with the <br />side slopes at 2:1 v+as used in their design. Armstrong conducted field and <br />laboratory tests and determined that 95h (ASTt~1 D698) maximum dry density of <br />the reject material was required for the pile to have a computed safety factor <br />against slope failure of one and one-half. It was further determined that <br />95% compaction could be obtained by wheel rolling not more than 2 foot loose <br />lifts of reject material with a Model 560 International Harvester front-end <br />loader at a moisture content of 25 to 30 percent. <br />The Armstrong report also presented designs and recommendations for drainage <br />of surface runoff, internal moisture and foundation drainage. This report has <br />• previously been submitted to the Colorado Mined Land Reclamation Board and is <br />reproduced in part as Appendix .E in this report, only for the purpose of having <br />all pertinent materials in one volume. <br />Summary of ARIX Report <br />It was found by GEX-Colorado that certain of the recommendations by Arm- <br />strong were not desirable to construct due to the operating conditions at the <br />specific time. Accordingly, ARIX was retained to study possible modifications <br />to the drainage plan which had previously been approved. The concepts presented <br />eliminated the need to remove a major portion of the original reject pile and <br />construct a foundation drainage blanket and internal drainage. <br />The study found that moisture from newly placed reject and from precipita- <br />tion generally ran off the pile with little or no moisture permeating into the <br />pile. This eras verified by numerous field and laboratory tests on new reject <br />material. <br />