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Response: The above described typographical error in the footer has been rendered <br />moot. The entire portion of Exhibit T, Item 20 , Part C that had the erroneous footers is <br />being replaced with new SEDCAD modeling summaries based on the revised post-mining <br />topography included in this submittal. The pages with the erroneous footer designation <br />included pages Exh. 7-20C-7 through Exh. 7-20C-78. The new SEDCAD output <br />summaries are still being included at the end of the Exhibit 7, Item 20, Part C discussion, <br />and will not likely include the same number of pages. <br />14. Colowyo provides introductory text for the South Taylor sediment ponds in Exhibit 7, <br />Item 20 in Volume 13. This introduction is on Pages Exh.7-20-1 through Exh.7-20-7 and <br />contains information regarding soil groups, SEDCAD curve numbers and other <br />assumptions that are used in the SEDCAD modeling of ponds and ditches. This general <br />SEDCAD information was changed and updated as a result of TR-73 for the day-forward <br />modeling at the Colowyo Mine (all ponds and ditches modeled with the pre-TR-73 curve <br />numbers do not need to be remodeled with the TR-73 curve numbers unless changes are <br />made). Colowyo provided new SEDCAD models for the West Taylor Pond and used the <br />new (TR-73) SEDCAD curve numbers. The curve numbers used are correct, based on TR- <br />73, but there is no information regarding these numbers in the introduction. Please add <br />either a separate introduction for Exhibit 7, Item 20, Part C, the West Taylor Pond, <br />that discusses the new curve numbers and SEDCAD assumptions (based on TR-73) <br />or add an addendum or additional introduction to the introduction that is currently in <br />place (Pages Exh.7-20-1 through Exh.7-20-7). Please update the Table of Contents <br />Page Exh.7-20-ii as needed to reflect the changes to the introduction information. <br />Response: An updated page Exh. 7-20-ii is provided with this submittal. The introductory <br />text to Exhibit 7, Item 20, Part C is being revised with this submittal to provide supporting <br />SEDCAD modeling. <br />15. On Page Exh.7-20-7 Colowyo provides Table 4, which is a summary of the sediment <br />ponds in the South Taylor area. This table has not been updated with the new information <br />from the updated SEDCAD modeling for the West Taylor Pond. Please update Table 4 <br />(Page Exh.7-20-7) for the West Taylor Pond. The subheadings that need to be <br />updated are watershed area, hydrologic parameters and sediment loading <br />parameters. <br />Response: This table is being revised with this submittal. The original design basis is <br />being retained and an additional column has been added.