Table 2-2. Components of Water Quality Standards
Water Quality Standards Component Definition
Designated Uses Those uses specified in water quality standards for each water body or segment whether or not they are being attained (40 CFR §131.3). Typical uses include public water supplies, propagation of fish and wildlife, recreation, agriculture, industry, or navigation.
Water Quality Criteria Elements of State water quality standards, expressed as constituent concentrations, levels, or narrative statements, representing a quality of water that supports a particular use. When criteria are met, water quality will generally protect the designated use (40 CFR §131.3)
Antidegradation Antidegradation is a policy required in State water quality standards to protect their waters from degradation. At a minimum, States must maintain and protect the quality of waters to support existing uses. Antidegradation was originally based on the spirit, intent, and goals of the Clean Water Act, especially the clause "...restore and maintain the chemical, physical, and biological integrity of the Nation's waters".