PERMFILE107555

• Permit No: C1982057
• IBM Index Class Name: Permit File
• Doc Date: 12/5/2005
• Section_Exhibit Name: Tab 17 Probable Part 2
• Media Type: D
• Archive: No

Wolf Creek Overburden Aquifer: L=(635 mg/1]x[570 gal/day]x[4.17x10"']=0.0015 tons/day
Wolf Creek Coal Aquifer: L=[730 mg/1]x[153 gal/day]x[4.17x10-s1=0.0005 tons/day
TOTAL:L=[0.001 tons/day]+[0.0012 tons/day]+0.0015 tons/day+0.0005 tons/day=0.004
tons/day
Dry Creek (monitoring station WSD5) has a reported, premining (1982 through 19901, mean TDS
value of 1,148 mg/I, and a mean discharge for the time period from June through September
li.e., low flow/irrigation season) of 1,5 cubic feet per second Icfs). Therefore, the chemical load
of Dry Creek is calculated as follows:
L = [1.5 cfs) x [1,148 mg/I] x [2.7 x 103] = 4.65 tons/day
Using the estimated chemical load values derived above, and mean discharge rate reported for
Dry Creek and the mean pit discharge lexpressed in acre-feed, the resulting Dry Creek TDS
concentrations with Wadge-only pit inflow, a combination of WadgelWolf Creek pit inflows, and
Sage Creek/Wolf Creek pit inflows are:
Watlge pit inflow:
[.032tons l day]+[4.65tons l day]
TDS = ~X 735.77
[0.012acre - ft l day]+ [2.97acre - ft l day]
TDS = 1,155 mg/L
WadgelSage Creek/Wolf Creek pit inflow:
[.023tons l day]+[4.65tons l day]
TDS = X735.77
[0.009acre- ft l day]+[2.97acre- ft l day]
TDS = 1,154 mg/L
Sage CreeklWolf Creek pit inflow:
[.004tons /day] + [4.65tons l day]
TDS - X735.77
[0.004acre - ft l day] + [2.97acre - ft l day]
TDS = 1,151 mglL
The TDS value of 1,155 mg/l, which is the predicted load for the Wadge-only pit inflow
contributions represents a 0.6 percent increase in the premining Dry Creek TDS mean value of
1,148 mg/I. The Wadge-Wolf Creek and Sage Creek/Wolf Creek pit inflow TDS values represent
0.5 and 0.3 percent increases, respectively, over the premining Dry Creek TDS mean value of
1,148 mg/I. This predicted loading increase is a conservative, worst-case scenario because the
98 Revised 1/02