Mich. Comp. Laws § 46.171

Sec. 1. (1) The county board of commissioners of a county may, by resolution adopted by a majority vote of its members-elect at any regular or special session of the board, authorize and direct that there be established a system or systems of water, sewer, or sewage disposal improvements and services and garbage or rubbish collection and disposal facilities and services within or between cities, villages, townships, charter townships, or any duly authorized and established combinations thereof, within or without the county, and mains, trunks, connecting lines, and disposal facilities therefor. For such purposes the agency of the county hereinafter designated shall locate, acquire, purchase, construct, own, maintain, or operate water mains, trunks, and connecting lines, water pumping and purification plants, sewers, sewage interceptors, sewage disposal plants, settling basins, screens and meters, and incinerators and disposal grounds and facilities, as shall be described in maps, plans, and specifications therefor and be approved by the county board of commissioners or contract with any unit of government, or any duly authorized and established combination thereof for the purchase of water and for the use of their sewers and sewage disposal plants and garbage or rubbish collection and disposal facilities and services. A county may establish, construct, administer, coordinate, and regulate systems for water, sewer, and sewage disposal improvements and services within or between, and garbage and rubbish collection and disposal facilities and services for, such units of government. (2) As used in this act: (a) "Sewers" means interceptor sewers for the transportation of sewage or storm water or both, storm sewers, sanitary sewers, combined sanitary and storm sewers and all instrumentalities, facilities, and properties used or useful in connection with the collection of sewage or storm water. (b) "Garbage" and "rubbish collection and disposal facilities" mean incinerators, disposal grounds, and all instrumentalities, facilities, and properties used or useful in connection with the collection and disposal of garbage and rubbish. (c) "Unit of government" means a city, village, township, charter township, and any duly authorized and established combinations thereof, within or without the county establishing any of the improvements, facilities, or services authorized under this act. (d) "Improvements", "facilities", and "services" mean any of the improvements, facilities, and services authorized under the provisions of subsection (1).