2017-01-12_REVISION - C1981019 (13)

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contamination from mining in this area, and there is no reason to believe that ground water contamination has occurred. Any ground water in alluvial deposits in the bond release area meets the classification of Limited Use and Quality because the alluvial water is of such small volume and is unlikely to be used in the future. The Basic Standards for Ground Water have no water quality standards for the Limited Use and Quality classification. Surface Water Impacts All of the runoff from the SL -10 areas flow into one of the following sediment ponds: Gulch A Pond, Streeter Pond, West Pit Pond or the East Taylor Pond. All of these ponds are inspected on a regular basis by the Division as well as quarterly by Colowyo. All of these ponds have been found to be in good repair and properly functioning. None of these ponds are included in the SL -10 Bond Release application. All four ponds are associated with outfalls in the Colorado Discharges Permit System permit number CO -0045161. Exceedances of discharge limitations that have not been the result of runoff (when alternate limitations were in effect) have been very rare and not indicative of a threat to water quality. Findings on Protection of Hydrologic Balance Based on the foregoing observations, the Division finds that the Colowyo Mine has minimize d disturbance of the hydrologic balance in the SL -10 bond release area and prevented material damage outside the permit area. The Division also fmds that Colowyo Mine has no caused hydrologic changes that adversely affect the approved post mining land use in the permit area. Re vegetation The twelve reclamation parcels, totaling 202.4 acres, included in the Partial Phase III Bond Release SL -10 are EP036, EP037, EP038, EP039, EP040, EP041, EP042, EP043, EP044, WP008, WP009, and WPO11. Nine of the reclamation parcels are located in the East Pit and account for 190.1 acres. Three of the reclamation parcels are located in the West Pit and account for 12.3 acres. The locations of the reclamation parcels are shown in Figure 1 of this document. The reclamation blocks were seeded between 2000 and 2003. The seed mixes used for reclamation parcels can be found in Tables 2.05-7, 2.05-8 and 2.05-9 in Colowyo's PAP. The post -mining land use for the Phase III Bond Release area is rangeland, as defined by Rule 1.04(71)(c). The Colowyo Mine uses two reference areas for the comparison of success of their reclamation parcels. The reference areas are the sagebrush reference area (established 198 1) and the mountain shrub reference area (established in 1980, which is further separated into a mesic aspect and a xeric aspect). Success standards are based on weighted average of the pre -mining vegetation communities in each reclamation block (as shown on Map 3 and 4 in Colowyo's PAP). Permit Page 4.15-18 states that the "...herbaceous cover of the revegetated area will be considered Proposed Decision and Findings of Compliance January 2017 Partial Phase III Bond Release SL -10 Page 7