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Figure 1 state that this study was for five highwall mining panels in the <br />orientation shown on Figure 1. The information in the Agapito report, <br />however, does not correlate with the information shown on revised Map 23A. <br />On Map 23A there are two discrete highwall mining areas and the layout of <br />the highwall mining panels appears to be different than that shown in the <br />Agapito report. <br />The Division also questions whether the proposed highwall mining in the <br />northwest portion of the South Taylor Pit as depicted on Map 23A is included <br />in the Agapito study area. In Section 4.23.9, page 4.23-2 of the PAP, <br />Colowyo states that highwall mining is designed for zero subsidence. Please <br />provide documentation that the highwall mining proposed on Map 23A will <br />meet Colowyo's design commitment for zero subsidence and will also meet <br />the guidelines that have been developed for web and barrier pillars by <br />Agapito. Please document that the proposed change in highwall miner <br />orientation shown on Map 23A will conform to the Agapito web and barrier <br />pillar design guidelines. <br />In the first paragraph of the Agapito report it is stated that "...no critical <br />structures overlie the planned mining. We further understand that a power <br />line on the ridge overlying the highwall mining panels will be relocated, so no <br />protective measures are required." A review of Map 22A - Existing <br />Structures South Area, however, reveals that there is a 345 kV power line that <br />will be undermined by the proposed highwall mining. The Agapito report <br />states there will need to be "protective measures" to ensure that there is no <br />impact to the power line. Since the power line is located above the proposed <br />highwall mining, please provide the Division with a narrative of the protective <br />measures that will be employed to ensure there is no impact to the power line. <br />These protective measures need to be more than a general statement that the <br />proper measures will be taken to ensure that there is no impact to the power <br />line [Rule 4.23.2(6)(d), please describe the specific protective measures that <br />will be undertaken. A change to the text in the South Taylor portion of the <br />permit as well as an engineering report or similar study will be necessary. <br />4. The Agapito report states that they recommend Colowyo use the design <br />curves for web pillar design, barrier pillar design and recovery presented in <br />Figures 23a through 23c, which are attached to their 13 April 2007 report, due <br />to the highwall mining's proximity to drill hole WP-05-08. This statement <br />and these figures are important as the design of web and barrier pillars (based <br />on pillar width and depth) is critically important to the zero subsidence plan. <br />The Division would like to see a reference to these Figures in the text as it <br />relates to the zero subsidence plan for highwall mining in the South Taylor <br />Pit. <br />Colowyo has provided a letter from Shannon and Wilson, Inc. (Shannon), <br />dated 21 November 2008, that states "...the highwall mining will not