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Technical Revision 37 <br />Response to Adequacy Comments <br />Page 7 <br />• appropriate stream segment standards. Please refer to the Seneca II Mine Permanent Impoundment WaterQuality and Water Right <br />Demonstrations permit application package pages 7-379 through 7-387. <br />Response: Water quality sampling results have been tabulated and included in this package. <br />20. In the Permanent Impoundment Demonstrations Appendix 20-1.2, SCC indicates that they have a mater right for Pond 010 and no <br />mater rights for Ponds 013 and 014. For Pond 010, please provide the mater right decree or reference its location and summarite the <br />decreed amount and Case No. in the Permanent Impoundment Demonstration. For all three permanent pond requests (010, 013, and <br />014) appropriate application materials should be submitted to the Office of the State Engineer for the permanent structures. All <br />impoundments that are intended to be retained as permanent postmining features shall comply with applicable State Engineer rules and <br />regulations. Under the State Engineers rules a permit is required but mater rights are not required for Livestock Water Tanks or <br />Erosion Control Dams, which maybe applicable to Ponds 013 and 014. State Engineer and DBMS approval shall be obtained <br />before bond release can occur. <br />Response: Water Right information has been included in the permanent pond demonstration for Pond 010. SCC has <br />been in contact with the Office of the State Engineer regarding approval of the requested permanent ponds. <br />Documentation will be provided as soon as it is received from the SEO. <br />21. The Permanent Impoundment Demon tration for Pond 012 is not appropriate at this time since the pond configuration is not stable and <br />anew design and subsequent as-built will be submitted for Pond 012. Please withdraw the Permanent Impoundment Demonstration <br />for Pond 012 from TR-37. <br />Response: The permanent impoundment demonstration has been removed from the TR-37 package. <br />• 22. For Stockpond ST-1 Permanent Impoundment Demonstration, insufficient information was provided regarding spillway capacity. <br />Them was no SEDCAD demonstration provided as referenced in the demonstration. The peak flom from the 25year, 24-hour storm <br />event, the depth of jlom and freeboard with emergency spillway jlowing at design depth were not provided Please provide the SEDCAD <br />run and information listed above. <br />Response: An as-built 25 year/24 hour SEDCAD demonstration for Stockpond ST-1 is included with this response <br />package. As shown in the SEDCAD results, the peak outflow through the emergency spillway from the 25-year, 24- <br />hour storm event is 7.6 cubic feet per second. The flow depth is 0.4 feet, and the design depth (with freeboard) is 1.4 <br />feet. <br />23. Under the capacity discussion, SCC indicates that ",since the capacity is under 2 ac. ft. limit, the State Engineer's office does not need to <br />review the permanency request': Please provideyour reference for the two acre feet limit. Based on our discussions with the Office of the <br />State Engineer, the two acre feet limit only applies to Erosion Control Dams with respect to the location of an outlet at or below the two <br />acre feet storage volume level. Permits or notification may still be required by the State Engineer for these structures. This structure was <br />legally constructed under DRMS jurisdiction. However, at the time of bond release all impoundments including stockponds that are <br />intended to be retained as permanent postmining features shall comply with the applicable State Engineer rules and regulations State <br />Engineer and DRMS approval shall be obtained for this structure before bond release can occur. <br />Response: As stated in CSR Title 35-Agriculture, Article 49 - Livestock Water Tank Act of Colorado, Section 35-49- <br />107 (2) "The provisions of this section and section 35-49-112 specifying approval by the state engineer and providing a <br />fee therefore shall not apply to dams having a vertical height not exceeding five feet from the bottom of channel to the <br />bottom of the spillway and which impound not more than two acre feet of water." SCC assumes that this reference <br />adequately addresses your concern. <br />24. An error was noted under the capacity discussion of the Stockpond ST-1 Permanent Pond Demonstration, SCC states that "The <br />0 Factor of Safety from this analysir shows 1.3 ". This should read `A safety factorgrrater than 1.3 was calculated by this analysis ".