Idaho water quality regulators must go back to the drawing board after the federal Environmental Protection Agency rejected a rule that allowed some pollution to be discharged into state waterways without a review.
In 2011, the EPA actually approved an Idaho Department of Environmental Quality rule exempting activities such as mining from review in some instances, provided their accompanying water pollution fell below a certain threshold.
The Greater Yellowstone Coalition sued, saying that was too lenient, especially in instances where cumulative pollution could eventually so significant harm to aquatic ecosystems.
In April, the EPA agreed in federal court in Pocatello to reconsider Idaho's rule.
And Tuesday, the agency concluded DEQ's rule went too far in exempting polluting activities from scrutiny and gave the agency several options to remedy the situation.