Ohio Rev. Code Ann. § 6103.21

At any time after the formation of any county sewer district, the board of county commissioners may enter into a contract, upon the terms and for the period of time that is mutually agreed upon, with any other public agency to prepare all necessary plans and estimates of cost and to acquire or construct any water supply facilities that are to be used jointly by the contracting parties, and to provide for the furnishing of water and for the maintenance, operation, and joint use by the contracting parties of those water supply facilities or the maintenance, operation, and joint use of any suitable existing water supply or water supply facilities belonging to either of the contracting parties.