2021-03-31_REVISION - C1982057 (3)

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land(Mandatory Standard 1),with at least 10%of the un-fenced acreage,possessing> 1,000 stems per acre (Mandatory Standard 2). Fenced woody plant density concentration areas are held to secondary standards(1-3, outlined in Tab 22 of the PAP).There are no fenced concentration areas within the BRB5, so the secondary standards are not applicable to the SL7 application. The species diversity success standard uses data collected from cover sampling. Four tests are used to determine revegetation success for species diversity. Success is demonstrated by passing the first(A),and at least two of the remaining three (B, C,and D),tests. These tests are described at length in Tab 22 of the PAP and the CCAI revegetation monitoring report included as Appendix D of the SL7 application. 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 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 and groundwater monitoring installations will remain until final phase III bond release. Water rights have been protected and a water augmentation plan was put in place for the over appropriated Yampa River. Alluvial Valley Floors 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 subirrigated fields in the Dry Creek drainage as well as flood irrigated fields in the Sage Creek drainage. A determination was made that any subirrigated sites are distant to the permit boundary lying some miles to the north. Post Mining Land Use The approved post mining land use for the lands applicable to SL7 is rangeland/wildlife habitat. The reclamation plan and the approved revegetation standards are designed to achieve the approved post mining land use. Livestock grazing has occurred on the sites reclaimed lands since 2007. Topsoil depth replacement information was included in the SL5 Phase II bond release application that was approved in 2014. Post Mine Land Use Post mining land use comprise livestock grazing and wildlife habitat. Grazing encompasses the majority of the reclaimed lands as granted by landowners. Grazing numbers range between 104 and 230 cow calf pairs. Permit Number: C1982057 Page 7 of 15 Phase III