Ohio Rev. Code § 305.15
When the services of an engineer are required with respect to roads, turnpikes, ditches, bridges, or any other matter, and when, on account of the amount of work to be performed, the board of county commissioners deems it necessary, upon the written request of the county engineer, the board may employ a registered professional engineer and as many assistant engineers, rodmen, and inspectors as are needed, and may also enter into contracts with any person, firm, partnership, association, or corporation qualified to perform engineering services in the state for this purpose and fix the compensation therefor. In awarding such contracts the board shall not be required to comply with sections 153.40 and 5555.61 of the Revised Code. If no such contract is entered into, the board shall furnish suitable offices, necessary books, stationery, instruments, and implements for the proper performance of the duties imposed on the engineer, assistant engineers, rodmen, and inspectors by such board.
R.C. §305.15