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zz <br />(4) In response to earlier comments regarding the development of final <br />plans and specifications for the proposed blanket drain, the consultant <br />has amended pages 24 and 25 of Appendix 3.3-3a. The amended text <br />commits to the construction of the blanket drain,". in accordance <br />with general criteria presented by the US Bureau of~Reclamation for <br />filter drains." Further, the text states that the drain system will <br />consist of pipes to transmit the collected water from beneath the <br />embankment. A pipe collector drain would be susceptible to <br />differential consolidation settlement disruption. If pipes are <br />included within the final design, blanket drains should be sized to <br />carry the projected flows without consideration of the pipeline's <br />capacity. Our eventual findings will reiterate the commitments <br />contained in the text of pages 24 and 25 of amended Appendix 3.3-3a, <br />concerning specifications for the blanket drain and collector drain <br />system, as well as all monitoring operations and facilities associated <br />with the drain. <br />(5) On amended page 26 of Appendix 3.3-3a, the consultant commits to the <br />development of a monitoring program to verify embankment stability <br />"...in the final design phase of the project and adjusted during <br />construction as necessary." Our eventual findings will reiterate this <br />commitment on page 26 of Appendix 3.3-3a, verbatim. It will be <br />necessary to stipulate a specific timeframe by which this plan for <br />monitoring the embankment stability of the proposed coal processing <br />waste structure must be developed and implemented. We cannot wait <br />until the life-of-mine, 300' high configuration, is achieved to <br />determine the slurry embankment's slope stability. <br />(6) On page 27 of the original version of Appendix 3.3-3a, the consultant <br />recommended "... the engineering characteristics of the coal refuse be <br />evaluated once sufficient quantities of refuse are available. A <br />reevaluation of the design of the embankment should be undertaken when <br />the properties of the coal refuse are known." Approval of the <br />embankment plan wilt include a stipulation requiring both the <br />completion of the material testing and the verification and/or <br />amendment of the engineered designs for the structure. <br />In summary, the applicant has submitted the majority of the information <br />required to comprise a "general plan" for the coal processing waste <br />embankment, as described in Rule 2.05.3(8)(a). With the addition of a <br />"certification statement that includes a schedule setting forth the dates that <br />any detailed design plan ... will be submitted to the Division", the general <br />plan would be complete. Amendment of the design to yield the required seismic <br />safety factor (see comment (1) above) would then render the general plan <br />technically adequate. The applicant has not, however, completed a "detailed <br />design plan", as described in that same rule. <br />In the alternative, the applicant could pursue phased approval of the coal <br />processing waste embankment structure. In order to pursue this approach, the <br />application would have to be amended to include appropriate stability analyses <br />for each of the separate phases' configurations, such as that of the starter <br />embankment. <br />