Laserfiche WebLink
Susan Burgmaier -9- February 7, 2014 <br />seven recommendations "to fulfill assumptions made in our evaluation and to ensure an <br />adequate safety margin for the gob pile ". Item 6 states, in part: "Gob must be placed <br />at, or slightly below its optimum moisture content. Gob placed significantly above the <br />optimum moisture content likely will not achieve adequate compaction or undrained <br />shear strength." Item 7 follows with, "We also recommend implementation of a <br />moisture content specification allowing moisture contents no greater than 4% above <br />the optimum moisture content." There does not appear to be a commitment by BRL in <br />the text portion of Volume XI to implement the moisture content recommendation. <br />Coal Mine Waste Bank reports are submitted by BRL on a quarterly basis. Included are <br />the results of any compaction tests conducted on coal mine waste placed during the <br />quarter. The Division observes that the moisture contents (MC) for approximately 25% <br />of the tests exceed the optimum MC by more than 4 %. For the first three quarters of <br />2013, the MC averages 2.2% greater than optimum. (These numbers reflect a <br />significant improvement over 2012 results, when the average MC was 4% above <br />optimum, and 40% of the tests were >4% above optimum.) Even with MCs that are <br />slightly high, BRL has been successful in achieving the minimum recommended 90% <br />compaction level 97% of the time in 2013. Please review the Recommendations <br />made by Buckhorn in 2007, in light of the coal mine waste compaction and <br />moisture content results obtained, to date, The Rules specify only that <br />compaction must be achieved, and do not specifically address the moisture <br />content of the coal mine waste. It is unclear whether Buckhorn's MC <br />recommendations constitute a permit requirement, as they are notrepeated <br />in the permit text. Clarifying language in the "Placement and Compaction" <br />portion of the permit would be beneFcial, Also, Buckhorn may wish to <br />provide an updated discussion of moisture content requirements / <br />recommendations with any response generated for Item 32, above, (Rule <br />4.10.4) <br />BOW2: Please see Buckhorn's response which is attached <br />34. DRMS: The Stability Analysis section on Page 11 of Volume XI refers to a Buckhorn <br />report dated 26 -Oct -2006, as does Buckhorn's 29- Mar -2007 report that was approved <br />under TR -45. The Division is unable to locate a copy of the 2006 report among the <br />Division's records. Was this report ofciall yapprovedunderaspecificrevision? <br />If it is not currently in the permit, please include this report as a proposed <br />addition to the permit application package. If it is currently incorporated <br />into the approved permit application package, please tell us where it is <br />located, (Rule 2.05.3(8)(a)(ii)(D)) <br />B W2: It is unknown if the October 26, 2006 was incorporated into the permit document <br />or not. It would have been during the TR -45 process. The report is included in BRL's <br />permit document. Please see attached October 26, 2006 Buckhorn Geotech <br />stability analysis. <br />