2025-10-07_REVISION - C1982057 (16)

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Permit Number: C1982057 Page 8 of 20 Phase III Rule 3.03.1(4) states: "No bond shall be fully released until all reclamation requirements of these Rules and the Act are fully met...". The same rule further states, "No acreage shall be released from the permit area until all surface coal mining and reclamation operations on that acreage have been completed in accordance with the approved reclamation plan." Permit Requirements: Success Standards The Seneca IIW Mine reclamation plan calls for a minimum of four feet of suitable plant growth medium, including an average of 1.3 feet of topsoil to be placed on graded lands prior to revegetation (Permit Tab 21). Topsoil depth replacement information was included in the SL5 Phase II bond release application that was approved in 2014. The approved revegetation plan is discussed in Tab 22 of the Seneca IIW Mine’s permit application package. Tab 22 describes the goals of reclamation, provides a revegetation plan and a description of how revegetation success will be demonstrated. The post mining land use approved for the site is livestock grazing and wildlife habitat with a greater emphasis placed on livestock grazing. Drainage control at the site comprises armored reconstructed drainages, sedimentation ponds and stock tanks as well as various secondary containment measures including check dams, diversion ditches, sediment sumps, contour ditches, riprap, and vegetative sediment filters among other methods. Sedimentation ponds have all been designed to meet State and Federal regulations and to provide storage and treatment for runoff resulting from 10-year 24-hour precipitation events. Protection of the hydrologic balance at the site comprises ground water and surface water monitoring for water quantity and water quality. The natural ground waters at the Seneca IIW mine comprise high concentrations of dissolved minerals and solids. It is expected that spoil utilized in reclamation will affect ground water quality as TDS (total dissolved solids), trends to increase over baseline levels. Seven sediment ponds are utilized for controlling surface runoff from disturbed areas. Six of the ponds are NPDES surface monitoring sites. Monitoring occurs in Sage and Dry Creeks as well as Hubberson Gulch. Surface water monitoring installations will remain. Water rights have been protected, and a water augmentation plan was put in place for the over appropriated Yampa River. Alluvial Valley Floors (AVF) A 1990 AFV study evaluated the Dry, Grassy and Sage Creek drainages around the Seneca IIW permit area with respect to their potential as AVF’s. As intermittent streams, Dry and Sage Creeks have insufficient carrying capacity to remove sediment built up from fans emanating from tributaries and sediment from valley slopes. The lower reaches comprise alluvium with limited water availability although there exist areas of flood irrigation. AVFs do exist adjacent to and downstream of the Seneca property. There is hydraulic communication with two sub-irrigated fields in the Dry Creek drainage as well as flood irrigated fields in the Sage Creek drainage, however these parcels do not meet the AVF criterion as per the 2005 assessment by ESCO Associates (Dr. David L. Buckner) due to the distance the flood irrigated fields are located in relation to the permit boundary. TDS evaluations indicate lower values than those predicted in the permit document. The quality of surface water would not be impacted and that irrigation and stock water, the permitted uses, would not experience material damage. This conclusion is supported by the water quality data from the past