Mich. Comp. Laws § 46.176

Sec. 6. The county board of commissioners shall designate either a committee selected from its membership or the board of auditors, if a county has a board of auditors, to be constituted as a board of review for the purpose of hearing and reviewing rates, charges, or assessments. At the request of any unit of government, person, firm, or corporation charged for services rendered by any county acting under this act, and on sufficient cause being shown, or upon information presented to or obtained by the board of review of the respective county, the action of the county agency in fixing or adjusting charges or assessments must be reviewed and finally determined by the board of review. The charges or assessments must in all cases be sufficient to pay the operating expenses of the system and to meet sinking fund and interest requirements on bonds and to meet principal and interest payments on notes if any, and any other requirements under which the bonds or notes may be issued. The board of review shall adjust and correct rates, charges, or assessments in order that the rates, charges, or assessments are just and equitable. The board of review shall meet at the room of the county board of commissioners in the county building within 60 days of a written request to review rates, charges, or assessments. The board of review shall allow sufficient time for the hearing. Notice of hearings to be held by the board of review must be prepared by the board and posted at 2 public places in each municipality where rates, charges, or assessments are charged or assessed under this act at least 7 days before the scheduled hearing.