Mich. Comp. Laws § 123.161

Sec. 1. As used in this act: (a) "Municipality" means a county, city, township, village, or metropolitan district. (b) "Person" means an individual, firm, partnership, association, or corporation which is the owner or occupant of any house or other building or any premises, lot, or parcel of land. (c) "Sewage system" means a sewage disposal system, including sanitary sewers, combined sanitary and storm sewers, plants, works, instrumentalities, and properties used or useful in connection with the collection, treatment, or disposal of sewage or industrial wastes.