Ohio Rev. Code Ann. § 5595.10

The county auditor of the county with the greatest population, according to the most recent federal decennial census, that is a party to the cooperative agreement shall be the fiscal officer for the governing board of the project. The county prosecutor of the county with the greatest population, according to the most recent federal decennial census, that is participating in the project shall be the legal advisor of the governing board of the project and shall prosecute and defend all suits and actions that the governing board directs or to which it is a party.