Ohio Rev. Code Ann. § 729.44

The advertisement for bids for the construction of a sewer under section 729.42 of the Revised Code shall be joint, and shall be filed with the clerk of the legislative authority of the municipal corporation, and reported to the legislative authority of each such municipal corporation. Any contract made for the construction of such sewer shall be in the names of the municipal corporations jointly, but each shall be liable only for such portion of the cost as is specified in the ordinances providing therefor.