Ohio Rev. Code § 6117.09
Any owner of property to be assessed or taxed for an improvement under sections 6117.01 to 6117.45 or sections 6103.01 to 6103.30 of the Revised Code, may appeal to the probate court from the action of the board of county commissioners in determining to proceed with the improvement in regard to any of the following matters:
Such appeal shall be effected within ten days after the passage of the resolution to proceed with the improvement. No appeal shall be allowed from said decision of the board except as to the tentative apportionment of the assessment if the owners of land tentatively assessed for at least eighty-five per cent of the cost of said improvement under sections 6117.01 to 6117.45, or sections 6103.01 to 6103.30 of the Revised Code, have consented in writing to the action of the board in determining to proceed with said improvement. If such an appeal to the probate court has been perfected by any property owner prior to procuring such consent in writing of the owners of land tentatively assessed for at least eighty-five per cent of the cost of said improvement, the probate court before whom such appeal is pending, on the motion of the board or any owner of land assessed for said improvements, shall dismiss so much of said appeal as refers to the necessity of the improvement or the boundaries of said district upon the introduction of satisfactory proof of such written consent of the owners of land tentatively assessed for at least eighty-five per cent of the cost of the improvement as provided for in this section. Such property owner may also appeal from the decision of the board in refusing to grant the prayer of any petition for improvements under sections 6117.01 to 6117.40 of the Revised Code. If the director of environmental protection has made an order declaring that any improvement is necessary for the public health and welfare as provided in section 6117.34 or 6103.17 of the Revised Code, no property owner shall have the right to appeal from the action of the board declaring such improvement necessary.
R.C. § 6117.09