2013-04-10_PERMIT FILE - C1981018A

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1 X Last Chance Pond Volume Gallons Acre feel �{- Primary Spillway 76,600 0.235 + Emergency Spillway 108,200 0.332 / J I DISCHARGE TO WASH s +- ti. r b SH -34 m� i a X Pond volumes at point of dis.;hargF. Pond Vol gallons Vol acre feel ! 1 56,300 0.173 -�- 2 65,700 0.202 X 3 52,200 0.160 a 64,200 0.197 5 243,000 0.746 i 6 316,400 0.971 �( X Scale: 1" = 100' Dewatering Pond Typical Cross Sections -2 4 �.,�aL /sNUwRY �paICINRL GRWNO TOPSOIL o -Too G +s n +lo o +ls 0+20 u +21 aao 0-e3e a. 40 SECTION D - D' SUaSOIL +2 SPILLWAY \aLVAININ __ /OPoGINPL GROUND SUBSgL D 2 4 G 0 +00 0 +20 11 +40 0 +60 U +NO 0 +100 0+120 0 +140 0 +160 SECTION E - E' Drawing I'll l N: \PERP i EMERGENCY SPILLWAY Water from the B -seam will be pumped through Service Hole SH -3 to the surface. This water is expected to carry excessive suspended solids which will be treated by the settling ponds shown on this drawing. Following settling and passing through the artificial wetlands this water will be discharged via an approved NPDES discharge point. Designs shown are the initial construction. Slight modifications may occur during operation to better improve efficiency of the structures while preserving the intent and general character of the designs. Hydrologic modeling only used Ponds 3, 4, and the 'Last Chance' pond. The first two ponds are considered operational for handling sediment. Ponds 5 and 6 were added to incorporate addition safety factor allowing more time to respond to unforeseen treatment needs. Artificial wetland are expected to evolve over time. Current construction is shown with additions/ modifications expected within the wetland footprint shown. The intent is to create shallow wetlands over approximately 50% of the area. The actual extent will be dictated, in part, by the rate water is pumped from underground. Water will be distributed through a series of berms and trenches. Best management practices will be used to control erosion prior to vegetation establishment. The area is surrounded by an exclosure fence designed to keep livestock out. This is necessary to prevent damage to the wetlands and diversion structures associated with this facility. See Illustration 55 for detailed hydrologic modeling. This modeling includes only portions of the total system. Therefore, the model is highly conservative as much more retention time and storage is in place. I have inspected the impoundments described herein and certify that they have been constructed to the C intent oft nd in accordance with the approv Utt°F abI Pgulations. .O . «.. (qJ0 43992 Last Chance Pond Scale: 1" = 20' Contour interval: 1 foot H' 1 2 3 4 i/ C' SPILLWAY As -built to add more detail tewatering Ponds 5 $ 6 indudina Ponds 5 and 6 Re,Aaion I -FD 'H' FLOP A' Scale: 1" = 10' C' y1.D 2.0' f III IF 1' MIN �4' 2' aso RIP RAP L5 AT HIGHEST IA I \4' 1 -3• RIP RV IN EMBANKMENT SECTION A -A' a -12• THICK 12- d50 RIP RAP SECTION B-B' Q`P'O\�ye`C� 4r 5608 /FINISHED POND EMBANKMENT ,,ORIGINAL GROUND �— 5606 SPILLWAY FLOW�NE� 1' —�IXI ING GROUND 5604 '�RNISHED POND IXCAVATON RUME 5602 5800 CHANNEL ROW LINE 5598 0 +00 0 +10 0 +20 0430 0 +00 0 +50 0 +60 SECTION C -C' 5608.00 5607.75 560750 5607.25 5607.D0 5606.75 0+00 212012 Date Clr /ORIGINAL GROUND 0 +10 0 +20 FlNISHED POND EMBANKMENT \ \ \\ EMERGENCY SPUWAY FLOW UN \ 0 1 M 0+40 0 +50 01 -60 SECTION D -D' ^7 — i O ` 13 C �q 1 � f�►� i�ZIZ -155 - � 65 BLUE MOUNTAIN ENERGY, INC. DESERADO MINE RANGELY, COLORADO Map 157 B -Seam Dewatering g. by: Dwg. Me Name: scw L by: Appr. by de: as noted Date. 4/17/2012 Rev. 4