Section 324.1703 - Rebuttal evidence; affirmative defense; burden of proof; referee; costs(1) When the plaintiff in the action has made a prima facie showing that the conduct of the defendant has polluted, impaired, or destroyed or is likely to pollute, impair, or destroy the air, water, or other natural resources or the public trust in these resources, 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 to defendant's conduct and that his or her conduct is consistent with the promotion of the public health, safety, and welfare in light of the state's paramount concern for the protection of its natural resources from pollution, impairment, or destruction. Except as to the affirmative defense, the principles of burden of proof and weight of the evidence generally applicable in civil actions in the circuit courts apply to actions brought under this part.(2) The court may appoint a master or referee, who shall be a disinterested person and technically qualified, to take testimony and make a record and a report of his or her findings to the court in the action.(3) Costs may be apportioned to the parties if the interests of justice require.1994, Act 451, Eff. 3/30/1995 .