The goal of the federal Clean Water Act (CWA) is to restore and maintain the chemical, physical and biological integrity of the nation’s waters. Water quality standards are the foundation for a wide range of programs under the CWA. Water quality standards establish the water quality goals for a specific water body, or portion of that water body. For more information about federal requirements, visit the U.S. Environmental Protection Agency's Water Quality Standards: Regulations and Resources webpage.
State Regulations
Missouri’s water quality standards are defined in Code of State Regulations 10 CSR 20-7.031. These standards describe the desired condition of Missouri's water bodies and how those conditions will be protected or reached. Water quality standards contain the following core components:
- Designated use or uses of a water body
- Criteria necessary to protect the designated uses
- Antidegradation requirements
The goal for water quality standards is protecting water uses through applying criteria. The level of protection given to a stream, river or lake depends on the expected use, or designated use(s), of that water, such as recreation or drinking water. When the department assigns designated uses to a water body, it is considered “classified” and listed in Missouri’s water quality standards. The water quality criteria for the assigned designated use, which is expressed as concentrations, loads or narrative statements, is then applied to the water body. Antidegradation requirements prevent pollutant discharges or activities that may cause surface waters already meeting water quality standards to drop below those standards.
Related Information
Contact Information
Water Protection Program
Division of Environmental Quality
P.O. Box 176
Jefferson City, MO 65102-0176
United States
