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d. Map 20B, Section B-B' - The extent and steepness of the permanent valley (West) fill <br />(Station 0+00 to 20+), are dramatically different that what was previously proposed and <br />approved. <br />Response: The post-mining topography is being significantly revised with this submittal, <br />but the changes to the toes of the fills are essentially the same as originally submitted with <br />TR-81, and they do extend further down-valley than in the approved PR-02. With regard to <br />steepness, all fill faces have been reconciled with Shannon and Wilson's recommendations <br />regarding maximum allowable slope angles and have been revised on the Map 20B and <br />Map 45 cross sections through the valley fills. <br />e. Map 2013, Section C-C' - The extent and steepness of the permanent valley (East) fill <br />have changed only slightly with TR-81, as has the PMT. However, the PMT (proposed <br />and previously approved) is more than 200 feet lower in elevation than the pre- <br />mining topography was. <br />Response: We believe CDRMS was referring to Section ST-C / ST-C' on Map 20 B. The <br />area described as having PMT more than 200 feet lower than pre-mining topography <br />appears south of Station 50+00 on Section ST-C / ST-C'. Referring again to Attached Fig. <br />1 "PMT Revised Areas for TR-81"; this area is well south of the area in which TR-81 seeks <br />to revise the PMT, and simply represents the approved PMT. <br />Map 2013, Section D-D' - The PMT from Station 40+00 to 82+00 is substantially higher <br />than what existed pre-mining (no change proposed with TR-81). This configuration <br />(increasing the backfill elevation above the mined-out area) seems preferable to <br />increasing the size of valley fills. <br />Response: This issue may have been rendered moot by the revised post-mining <br />topography associated with this revised submittal of TR-81. <br />g. Map 2013, Section E-E' - The PMT across the pit is up to 200 lower lower than the <br />pre-mining topography. No changes are proposed with TR-81. <br />These decreases in the currently approved post-mining topography are exactly what the <br />Division is concerned about with Colowyo's proposal to increase the volume in the <br />South Taylor Fills by 10.3 million cubic yards. This concern has addressed in several of <br />the TR-81 adequacy questions (questions 2, 3, 26 and 27). Please review the currently <br />approved post-mining topography map, Map 1913, as well as their respective cross- <br />sections, Maps 20, 20A and 2013, and explain how the changes discussed above are <br />acceptable within Colowyo's currently approved variance from AOC for steep slope <br />mining for the South Taylor Pit and explain how these changes meet the definition of <br />AOC. <br />Response: Similar to "e." above, we believe CDRMS was referring to Section ST-E / ST- <br />E' on Map 20 B. The area described as having PMT more than 200 feet lower than pre- <br />mining topography appears south of Station 30+00 on Section ST-E / ST-E'. Referring <br />again to Attached Fig. 1 "PMT Revised Areas for TR-81"; this area is well southwest of the <br />area in which TR-81 seeks to revise the PMT, and simply represents the approved PMT. <br />However, this submittal significantly revises the PMT such that PMT closely resembles pre-