Setting Clean Water Goals - Water Quality Standards

The Clean Water Act requires states like Wisconsin to identify the desired water quality for their streams, rivers and lakes in Wisconsin so that the waters are “fishable and swimmable.” These are known as “water quality standards” and they establish the levels of pollution that streams and lakes can withstand without harming fish, human health, recreation, or wildlife.
Water quality standards contain two components: 1) the designated use of a waterbody (such as the protection of a cold or warm water fishery), and 2) specific water quality “criteria” established to preserve and protect that use.

Wisconsin DNR has set use designations for all of the streams, lakes and rivers in the state. These include Outstanding Resource Waters, Exceptional Resource Waters, Fish and Aquatic Life waters, Great Lakes System waters, and public drinking water supply. All waters of the state are designated for Recreational Use, Public Health and Welfare, and Wildlife. The DNR has created several subcategories of the “Fish and Aquatic Life” use, including:

• cold water communities (e.g. trout waters)
• warm water sport fish communities (e.g. bass waters)
• warm water forage fish communities (e.g panfish)
• limited forage fish communities, and limited aquatic life

One water quality criterion pertaining to the “Fish and Aquatic Life” designated use, for example, addresses levels of dissolved oxygen in water.  Fish cannot breathe without a certain level of dissolved oxygen; therefore, Wisconsin has set 5.0 milligrams per liter of dissolved oxygen to protect bass, walleye, and other fish that might be found in a stream or lake that supports a “warm water sport fishery.”  This criterion thus supports the health of any waterbody designated with this particular use.

The DNR has prepared guidelines for how it designates uses. In those guidelines, the DNR has changed the categories of designated uses, without actually promulgating a new rule. Because the categories above are what are listed by the DNR in its rules, we continue to use those categories.

The DNR may not remove designated uses if the use they propose is “attainable.” For example, if a stream can support trout, then the DNR may not remove the “cold water” designation and list the stream as a warm water sport fishery.

If the DNR wanted to remove the “cold water” designation, federal regulations require that it undertake a “Use Attainability Analysis.” In the past, the DNR has proposed to remove key designated uses without first undertaking Use Attainability Analyses for each of the streams.

The Clean Water Act requires DNR to review and update water quality standards, criteria, and designated uses every three years as part of a “triennial review.”

To read more about Midwest Environmental Advocates' Clean Water Campaign, click here.