Water quality standards are a product of the Federal Water Pollution Control Act of 1949 and subsequent amendments (commonly called the Clean Water Act since 1977). Under the Clean Water Act and its amendments, states must adopt water quality standards to protect, maintain and improve the quality of the nation's surface waters. Each state translates this imperative into a program that is designed to achieve the goals of the Clean Water Act. Ohio's program creates measurable standards by assigning every water body at least one beneficial use. Beneficial use designations describe existing or potential uses of water bodies. They take into consideration the use and value of public water supplies, protection and propagation of aquatic life, recreation in and on the water, and agricultural, industrial and other purposes.
Narrative and numerical water quality criteria are then established to protect that use. If the water quality criteria have been met, it is assumed the water body is adequately protected for its designated use. Use attainment is another way of saying whether or not a water body is meeting Ohio's water quality standards.
Various water quality indices and parameters are indicators of whether the criteria have been met. They are measured or observed in a water resource as part of a water quality monitoring program. The indices and parameters are quantifiable measures that are evaluated against ambient or background conditions for a region. Present day, ambient or background conditions are used as a benchmark for what is considered "exceptional" or "poor" water quality.
Use designations are assigned to water bodies based on both present and potential future use(s) of the water resource. Water bodies in Ohio have four general types of uses: 1) aquatic life habitat; 2) water supply; 3) recreation; and 4) state resource water.
All water bodies are assigned one or more aquatic life habitat use designations. The water resource may also be assigned one or more water supply use designations and/or recreational use designations. In addition, a water body may be designated a state resource water. Each of the four uses and their subcategories are described below.
Capable of supporting and maintaining a balanced community of warmwater aquatic organisms. This is the most widely applied use designation assigned to warmwater rivers and streams in Ohio.
"Temporary" aquatic life habitat use designation created in the 1978 Ohio Water Quality Standards for streams not meeting specific warmwater habitat criteria. This aquatic life use designation is being phased out.
Capable of supporting and maintaining an exceptional or unusual community of warmwater aquatic organisms with the general characteristics of being highly intolerant of adverse water quality conditions and/or being rare, threatened, endangered, or of special status. This is the most protective use designation assigned to warmwater rivers and streams in Ohio.
Incapable of supporting and maintaining a balanced community of warmwater aquatic organisms because of extensive and irretrievable modifications to the physical habitat. Examples include extensive cases of: stream channel modification; stream sedimentation from abandoned mine land runoff; and permanent impoundment of free-flowing water bodies.
Capable of supporting the passage of salmonids from October to May and large enough to support recreational fishing. This aquatic life habitat use designation is in effect from only October to May each year. Another aquatic life habitat use designation will be in effect the remainder of the year (June to September). A definition for salmonid is included in Appendix A.
Capable of supporting populations of coldwater aquatic organisms on an annual basis and/or put-and-take salmonid fishing. These water bodies are not necessarily capable of supporting the successful reproduction of salmonids and may be periodically stocked with these species.
Incapable of supporting and maintaining a balanced community of aquatic organisms because of natural background conditions or irretrievable human-induced conditions.
Suitable for human consumption and meets federal regulations for drinking water with conventional treatment. Criteria associated with this use designation apply within 500 yards of all surface water supply intakes for human consumption.
Suitable for irrigation and livestock watering without treatment.
Suitable for commercial and industrial uses. The degree of treatment varies according to specific use.
Recreation use designations are in effect only during the recreational season, May 1 - October 15, for all water bodies except those designated seasonal salmonid habitat. The recreational season for seasonal salmonid habitat begins June 1 instead of May 1, and ends September 30.
Suitable for swimming where a lifeguard and/or bathhouse facilities are present, and includes any additional areas where water quality is approved by the Director of Ohio EPA.
Suitable for full-body contact recreation, such as swimming, canoeing, and scuba diving with minimal threat to public health as a result of the water quality.
Suitable for partial-body contact recreation, such as but not limited to wading, with minimal threat to public health as a result of the water quality.
Water bodies which lie within park systems, wetlands, wildlife areas, and wild, scenic and recreational rivers, and publicly owned lakes, and waters of exceptional recreational or ecological significance.