PERMFILE117489

• Permit No: C1982057A
• IBM Index Class Name: Permit File
• Doc Date: 5/1/2003
• Section_Exhibit Name: Tab 17 Probable Hydrologic Consequences
• Media Type: D
• Archive: Yes

• 0 = the sun of the contaminant and receiving medics flow rates expressed in
acre-feet/day
F = a constant factor equal to 0.00136 and used for converting the product of
acre-feet and milligrams per liter into tons
Overburden and Wadge Coal Aquifers. The premi ni ng flow rates for the overburden and Wadge
Coal aquifers were calculated using the equation 0 = KIA. Average downg radient hi ghwall
resatura ti on levels will vary with the varying highwall heights. An average saturated
height of 60 feet was estimated in both pits. Table 17-17 lists the computational
assumptions and values used to calculate the bedrock aquifer flow rates. The following
equations present the premining and Postmining chemical load and TDS concentration changes
as a result of the spoil aquifer discharging into the downgradient overburden and Wadge
Coal aquifers.
Overburden Premi ni ng:
North Pit L = 0.0139 x 4072 x 0.0027 = 0.153 tons/day
Central Pit L = 0.054 x 4072 x 0.0027 = 0.594 tons/day
• Spoil Postmining:
North Pit Spoil L = 0.0139 x 4500 x 0.0027 = 0.169 tons/day
Center Pit Spoil L = 0.054 x 4500 x 0.0027 = 0.656 tons/day
Overburden Postmining:
Below North Pit DSC = 0.153 + 0.169 = 4385 mg/1 (7,71 TDS increase)
0.054 x 0.00136
Below Center Pit DSC = 0.594 + 0.656 = 4295 mg/1 (5.5~ TDS increase)
0.214 x 0.00136
Wadge Premining:
North Pit L = 0.00057 x 1513 x 0.0027 = 0.0023 tons/day
Center Pit L = 0.00091 x 1513 x 0.0027 = 0.0037 tons/day
Spoil Postmining:
North Pit Spoil L = 0.00057 x 4500 x 0.0027 = 0.007 tons/day
Center Pit Spoil L = 0.00091 x 4500 x 0.0027 = 0.011 tons/day
Wadge Postmining:
Below North Pit DSC = 0.0023 + 0,007 = 2630 mg/1 (74@ TDS increase)
0.0026 x 0.00136
• Below South Pit DSC = 0.0037 + 0.011 = 3002 mg/7 (98ge TDS increase)
0.0036 x 0.00136
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