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Section - 2.05.6
<br />Water Use, which is only 0.03 percent of the average annual stxeamflow for the North Foxk of
<br />470,000-acre feet per year based on an average flow of 650 cfs.
<br />TABLE 2.05.8.71
<br />PROJECTED CONSUMPTIVE WATER USE
<br />Water Rights (2 rights ~ 0.90 c/s)
<br />2 x 0.90cfs x 60sec x 60 minx 24 hrs x 365 days / 43,580
<br />= 7,300 of/yr available
<br />Consumptive Use
<br />Longwall Longwall
<br />(4.OMM tons per year) (6.OMM tons per year)
<br />Sanitary (® 50 gal/day/employee)
<br />200 employees 280 employees
<br />SOgal x 200empl x 250days SOgal x 280empl x 250days
<br />= 2,500,000 gal/yr = 3,500,000 gal/yr
<br />= 7.7 aflyr = 70.7 af/yr
<br /> Mining (as noted)
<br />Continuous Miner (Q SOgpm) Continuous Miner (Q 37.7gpm)
<br />0.5miners x SOgpm x 50min x 16hrs x 250days = 2.0 miners x 37.7gpm x 37min x 16hrs x 340days =
<br />5,000,000 gal/yr 15,177,000 gaUyr
<br />= 15.4 af/yr = 46.6 af/yr
<br />Roof Bolters (@ 8gpm) Roof Bolters (dry systems)
<br />0.5bolters x 8gpm x 50 minx 16hrs x 250 days = = 0 of/yr
<br />800,000 gal/yr
<br />= 2.5 of/yr
<br />Conveyor Transfers (Q 2gpm during warts weather, Conveyor Transfers (@ 2gpm during wane weather, ie: 6
<br />ie: 6 months) months)
<br />13 x 2gpm x 60min x 16hrs x 125days = 3,120,000 4 x 2gpm x 60min x lfihrs x 186 days = 1,428,000 gal/yr =
<br />galryr = 9.6 a(/yr 4.4 of/yr
<br />Oust Control (B,000gaI, twice a week during wane Dust Control (2,200 gal, 5 limes a day, during warm
<br />weather, ie: 6 months) weather, ie: 6 months)
<br />B,000gaI x 2 x 4wks x limos 2,200ga1 x 5 trips/day x limos
<br />= 384,000 galyr = 7.2 a//yr = 2,007,000 gal/yr = 6.2 of/yr
<br />Longwall (Q 40gpm includes 7 longwall move per Longwall ((03 82gpm inrAudes 1 longwall move per year))
<br />year)) 1 x 82gpm x SOmin x 16hrs x 320days = 20,992,000 gal/yr
<br />i x 40gpm x 50min x 24hrs x 320days = 15,360,000 = 64.4 of/yr
<br />gal/yr=47.1 of/yr _ _
<br />Pond Evaporatlon
<br />U er Hubbard Creek 870 N suAace area
<br />Pond A 840
<br />Pond B 70,400
<br />Pond C 9,600
<br />Pond D 10,100
<br />PondE future censWCtlon 11,000
<br />Pond F future construction 71,000
<br />East Yard Pond 3,660
<br />Substation Pond 1,080
<br />Dewatedn Pond 4,810
<br />Totals 41,360 = 0.95 acres 63,360 = 7.45 acres
<br />0.95 acres x 34in / 12in = 2.7 of/yr 1.45 acres x 34in / 12in = 4.7 af/yr
<br />excludes Pond E and F
<br />Total Consumptive Use
<br />86.2 of/yr (Longwall Q 4.OMM tons/yr) 136.4 of/yr (Longwall Q 6.OMM tons/yr)
<br />The OML.LC drainage and sediment control network is designed to function as the primary
<br />mitigation system to prevent significant impacts on surface water quality. Disturbed area runoff from
<br />precipitation events and snowmelt is intercepted and routed through sedimentation ponds with a
<br />minimum detention time of 24-hours. The discharge from these sedimentation ponds meets effluent
<br />standards through the use of decants that will be opened after settlement of suspended solids. The
<br />top of the decant pipe will be utilized as a visual indicator of maximum allowable water level for
<br />r~perntirnai dewatering. Opexatirn', o`. the sedur,entaticn ponds :nay rzsnk 71'r srm.e delay m water
<br />discharge to the receiving drainages potentially altering discharge volume and consequently
<br />streamflow downstream from- these structures and may increase concentrations of TDS and other
<br />constituents in the runoff retained in the pond due to evaporation.
<br />TR42 2.05-83 Revised Tanuarv 2003
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