2014-10-31_PERMIT FILE - C1981044A

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elevation in relation to discharge structure elevation. If water elevation is at or above the discharge elevation, the discharge gate is opened and the pond allowed to dewater to the invert of the discharge structure. The gate is then closed and the pond then has the capacity to retain runoff from any subsequent storm event. At the time the pond is dewatered, water samples are taken in accordance with the discharge permit requirements. Typically, only the HR pond and 9A -P1 discharge during the spring runoff period, or in response to major thunderstorms. As shown in Exhibit 18 (page 13 and on Map DWG IV -42), Pond 9A -P1 does not meet the size requirements of 4.05.9 (3), but is adequately designed to serve as a stock pond which is its intended postmining use. Nine years of pond inspections from 1983 to 1991 indicate that the pond is adequate for this intended use. Pond 9A -P1 normally fills in March, containing an average of 5.0 ac. ft. of water (range 0.7 to 7.5 ac. ft.) and then dries up in late July or August. This seasonal storage represents a valuable source of water for spring and early summer livestock grazing. Furthermore, it is the only accessible water on this property. Pond 9A-PI has only discharged once during the last eight years. This discharge was sampled on 03/13/90, and test results (ph 7.3, E.D. 86.8 t 25° C, oil and grease 0, TDS 94 mg/l, and Settleable Solids < 0.2 ml/l/hr) show that the quality is adequate for the intended use and will meet State and Federal water quality standards. Pond 9A -Pl will be inspected, and if necessary, surveyed immediately prior to final bond release, and if the survey shows any significant build -up of sediment that would adversely affect storage capacity, the pond will be cleaned. Williams Fork River Bank Stabilization - During the 1984 spring runoff, the Williams Fork River overtopped its banks, resulting in significant bank erosion. In order to protect the riverbank and mine facilities, minor backfilling and grading of eroded areas, areas subject to erosion, and transition areas of the Williams Fork Riverbank was completed, and riprap armoring was placed to protect these areas. The Williams Fork Riverbank Stabilization Plan is detailed in the United States Army Corps of Engineers Permit (33CFR325) included in Exhibit 2, Other Required Permits. In addition, elevated streamflows during the 2010 and 2011 runoff seasons resulted in debris dams and streambank erosion in the vicinity of the bridge abutments for the railroad spur bridge near the confluence of the Williams Fork and Yampa Rivers. Site - specific maintenance work was completed during 2010 and 2011 to remove the debris dams and repair the erosion and place large rock as armoring to stabilize and protect the bridge abutment areas. Livestock Ponds - Technical Revision Number 7 was submitted to and approved by the Division, detailing plans for installing livestock ponds. This revision has been inserted in the PAP as Exhibit 41. Soil Materials All recent surface disturbance activities have included recovery and stockpiling of available soil materials for use in reclamation, and this practice will be followed for any future surface disturbance activities. Given generally poor soil development and that most disturbance involves limited areas, typical soil recovery practices involve recovery and stockpiling of all available A and B soil horizon materials, without segregation. In areas where minor temporary disturbances occur involving light -truck or other equipment usage only, soil materials may not be salvaged if salvage would result in greater disturbance or soil contamination than the disturbance itself. In areas subject to short-term or very occasional traffic, the affected areas may be scarified and seeded using an approved seed mixture, as presented in Section 2.05.4 Reclamation Plan, if appropriate. In the event other than minor surface disturbance is involved, soil materials will be salvaged according to the following plan: Identification of the area(s) in which soil salvage operations are to occur, either through flagging or verbal description to supervisor of the area(s) Determination of appropriate salvage depth (target soil salvage depths have been determined and are summarized in a report by Jim Walsh presented in Exhibit 13, Soil Inventory-Mine Facilities, Disposal Site, and Pit 6 and 7 Areas) Recovery of available soil materials within the identified area and to the appropriate salvage depth and either direct replacement on areas to be reclaimed or placement in long -term stockpile(s) TR14 -36 2.05 -17 Revised 09/08/14