Minn. Stat. § 115.73: CERTIFICATION REQUIRED.

A person may not operate a water supply system or wastewater treatment facility unless the system or facility maintains at least one person that:

(1) is certified in a class equal to or higher than the class of the system or facility; and

(2) has full and active responsibility for the daily on-site operation of the system or facility, or of a portion of the system or facility if an additional operator or operators with appropriate certification are responsible for the remaining portions.