2012-05-30_PERMIT FILE - C1981012A (2)

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• Additional discharges into Pond 007 will include sump discharge from the raw and clean coal reclaim tunnel, and industrial building sump. These additional discharges will be infrequent, of short duration and of relatively small magnitude. Total estimated flow from these sources is 600 to 800 gpd. The surplus capacity in Pond 007 is more than adequate to handle the additional water volumes and sediment loads generated by these sources. Pond 006 will be placed in the New Elk preparation plant water -flow circuit as shown on Figure 4. The plant will require 70.9 gpm of make -up water at a 400 ton per hour feed rate. Pond 006 design is shown in Exhibit 19. Pond 006 will be a non - discharging structure. WFC has amended the current NPDES permit to allow for this. Installation of the Pond 006 emergency spillway is proposed to be completed by January 1, 1989. WFC will also be utilizing pond 006 as a polishing pond for the sewage treatment plant. WFC submitted design specifications and received construction approval for the sedimentation pond in the refuse disposal from area MSHA. The MSHA impoundment I.D. No. is 1211 -CO -9 -0039. The sedimentation pond is an earthen rolled dam with an embankment height of 28 feet. Exhibit 20, Refuse Pond Design and Certification, contains all design information and as built certification for this embankment. This embankment (Sediment Pond 008) will control runoff from the refuse disposal area. • It has been sized to handle runoff for the life of the refuse disposal area. During the present permit term, WFC submitted design details for permanent diversion of the Middle Fork of the Purgatoire River. This diversion was necessary to accommodate coal storage and preparation plant operations. The Division approved this permanent diversion and WFC completed the approximately 580 foot diversion in the spring and early summer of 1985. Additional 220 feet of diversion work maybe necessary when plant expansion becomes necessary to meet market demands. Designs will be submitted and approved prior to construction activities, although, the Division has approved the probably hydrologic consequences evaluation of the entire 800 feet during the approval of the initial 580 feet. Exhibit 21, Supporting Information for Permanent Diversion, contains the pertinent design information resulting from the Division's review of WFC's plans and specifications for this permanent diversion. Included in Exhibit 21 are the following design specifications: 1. Estimates of a 100 year storm event at the New Elk Mine, 2. Rip -rap revetment narrative and calculations for a 100 year storm event, 3. Fill calculations for alluvial groundwater movement, 4. Final design prior to construction of the permanent diversion, • 5. Diversion certification and as-built drawings, 6. Rip -rap material testing, and TR -49 2.05 -17 (Revised 10 -3 -06)