Ohio Rev. Code § 6131.13
The board of county commissioners, on application of owners interested or at its own discretion, may consolidate and treat as a petition for one improvement petitions pending at the same time for two or more separate improvements which connect with each other, or which serve common territory, or which can readily be combined into one system. In case of such consolidation, the board shall enter its action upon its journal, and if necessary, it shall order the county engineer to re-estimate and make such further reports and schedules as are necessary upon its order consolidating the improvements. If two or more improvements are consolidated, the proceedings after consolidation shall be the same as if all the matters were petitioned for in one petition.
R.C. § 6131.13