Minnesota Statutes Environmental Protection (Ch. 114C-116I) § 116B.04. Burden of proof

(a) In any action maintained under section 116B.03, where the subject of the action is conduct governed by any environmental quality standard, limitation, rule, order, license, stipulation agreement, or permit promulgated or issued by the Pollution Control Agency, Department of Natural Resources, Department of Health, or Department of Agriculture, whenever the plaintiff shall have made a prima facie showing that the conduct of the defendant violates or is likely to violate said environmental quality standard, limitation, rule, order, license, stipulation agreement, or permit, the defendant may rebut the prima facie showing by the submission of evidence to the contrary; provided, however, that where the environmental quality standards, limitations, rules, orders, licenses, stipulation agreements, or permits of two or more of the aforementioned agencies are inconsistent, the most stringent shall control.

(b) In any other action maintained under section 116B.03, whenever the plaintiff shall have made a prima facie showing that the conduct of the defendant has, or is likely to cause the pollution, impairment, or destruction of the air, water, land or other natural resources located within the state, the defendant may rebut the prima facie showing by the submission of evidence to the contrary. The defendant may also show, by way of an affirmative defense, that there is no feasible and prudent alternative and the conduct at issue is consistent with and reasonably required for promotion of the public health, safety, and welfare in light of the state's paramount concern for the protection of its air, water, land and other natural resources from pollution, impairment, or destruction. Economic considerations alone shall not constitute a defense hereunder.