Ohio Water Quality Standards (OAC 3745-1)
Complete Ohio water quality standards for surface waters under the Clean Water Act, including designated uses and numeric criteria.
Complete Ohio Administrative Code Chapter 3745-1 in PDF format. Contains Ohio’s surface water quality standards including designated use classifications, numeric criteria for individual pollutants, antidegradation provisions, and mixing zone rules. This is the primary regulatory source for surface water standards in Ohio and the basis for NPDES discharge permits issued by Ohio EPA.