Ohio Rev. Code § 6103.17
Whenever the legislative authority or board of health, or the officers performing the duties of a legislative authority or board of health, of a municipal corporation, the board of health of a general health district, or a board of township trustees makes complaint, in writing, to the environmental protection agency that unsafe water supply conditions exist in any county, the agency's director forthwith shall inquire into and investigate the conditions complained of. If, upon investigation of the complaint, the director finds that it is necessary for the public health and welfare that water supply facilities be acquired or constructed, maintained, and operated to serve any territory outside municipal corporations in any county, the director shall notify the board of county commissioners of the county of that finding and order that corrective action be taken. The board shall obey the order and proceed as provided in this chapter and section 6117.01 of the Revised Code to establish a county sewer district, if required, to provide the necessary funds, to acquire or construct the facilities, and to maintain and operate the facilities, as required by the order and in a manner that is satisfactory to the director. Any part or all of the cost of the facilities or of the maintenance and operation of the facilities may be assessed upon the benefited properties as provided in this chapter.
R.C. § 6103.17