Ohio Rev. Code Ann. § 3746.171

The director of environmental protection shall maintain a record of the properties for which covenants not to sue were issued under section 3746.12 of the Revised Code that involve institutional controls or activity and use limitations that restrict the use of the properties in order to comply with applicable standards. The records pertaining to those properties shall indicate the use restrictions or activity and use limitations applicable to each of them. At least once every five years, the director or an authorized representative of the director shall visually inspect each such property to determine whether the property is being used in compliance with the applicable institutional controls or activity and use limitations.