INDIANAPOLIS (AP) _ An environmental law judge says Indiana failed to fully assess the impact of coal waste runoff on local waterways when it issued a permit for the largest coal mine in the eastern U.S.
 
The Sierra Club challenged Indiana's general permit for Peabody Energy's Bear Run coal mine. It's the largest surface coal mine east of the Mississippi River.
 
The environmental group argued Indiana should have approved an individual permit requiring Peabody to thoroughly study the mine's discharges and analyze nearby waterways.
 
The state agency judge ruled against the Sierra Club on that argument, finding it “failed to present sufficient evidence'' justifying an individual permit.
 
But the judge found Indiana failed to perform a required analysis to ensure mine wastes won't harm local waterways and ruled that study must be conducted.