Bioassessment and Biocriteria Program Status for Wisconsin: Streams and Wadeable Rivers
State Program Contact
Water Quality Standards
The link to Wisconsin's WQS that are in effect for Clean Water Act purposes is provided. These are the WQS approved by EPA.
In addition to the links to WQS, Wisconsin provided links to its Department of Natural Resources website, which includes a summary of efforts to revise/create sections of their administrative code on designated aquatic life use, biological criteria, and antidegradation. More information will be posted on these site as it becomes available.
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Designated Aquatic Life Uses
Since the 1970s, Wisconsin has had ALU subcategories based on temperature and the associated fisheries expected. The five ALU subcategories are:
- Coldwater – Salmonids and some sculpin species
- Warm Water Sport Fish – game fish and some important forage species
- Warm Water Forage Fish – forage fish communities intolerant to low dissolved oxygen
- Limited Forage Fish – forage fish communities tolerant of low dissolved oxygen
- Limited Aquatic Life – communities with non-fish species (invertebrates, etc.) that are tolerant of low dissolved oxygen.
WDNR is currently undergoing a rulemaking process to revise its ALU categories.
Cold water communities
Warm water communities
Under the proposed rules, waterbodies in the above categories could additionally be designated as “altered” if the department demonstrates through a use attainability analysis that the aquatic life use is unattainable due to certain human-caused factors.
__X__ No criteria (in progress)
Narrative biocriteria language to prevent declining trends and loss of species;
Combined criteria for phosphorus that use biological metrics as phosphorus response indicators. The phosphorus response indicators for streams are benthic algal biomass and diatom taxa; for rivers the indicator is the frequency of moderate algae levels (suspended chlorophyll a).
Wisconsin is also working with EPA on refining numeric biocriteria thresholds for fish and macroinvertebrates for each stream/river type. These may be part of a future rulemaking effort.
The antidegradation rule is implemented in Chapter NR 207 of the Wisconsin Administrative Code.
Wisconsin expects to begin rule package to update the existing antidegradation rule. In addition, the proposed biocriteria rule package contains narrative biocriteria in NR 102 that would address antidegradation principles.
Benthic macroinvertebrates and fish are currently used for assessing streams and rivers. The thresholds used for these assessments are currently under revision.
A set of phosphorus response indicators for rivers and streams (including diatoms and suspended chlorophyll a) is being proposed for rulemaking.
Are bioassessments used to support 303(d) listings?
Yes. Listing methodology: Surface Water Quality Assessment Process
How are assemblages used to make impairment decisions?
Applied independently for impairment assessments if minimum data requirements (2 yrs) are met. If fewer biological samples are available, can use in conjunction with TP for an impairment decision. If rules are promulgated establishing biocriteria and phosphorus response indicators, assessment protocols would be updated. Biocriteria and algal abundance metrics would be applied independently. A new set of phosphorus response indicators (a.k.a. combined criteria) would be applied to waters exceeding the statewide phosphorus criteria but within a certain range, to determine whether the waterbody is exhibiting a biological response to phosphorus. This bioconfirmation process would contribute to phosphorus listing decisions.
Other uses of biocriteria or bioassessment within the water quality program:
Refining ALU, TMDL development and assessment, antidegradation, non-point source assessments, BMP evaluation, 305(b) surface water condition assessments, restoration goals, evaluation of discharge permit conditions, fishery assessments, and FERC re-licensing decisions, etc.
Technical Support Information and Documents:
Wisconsin has a least-impacted reference site dataset for wadeable streams. This dataset was used in setting proposed biocriteria for streams. These sites were selected based on 26 human disturbance variables, and span different stream sizes, flows, and ecoregions.
Wisconsin has a draft Technical Support Document that covers biocriteria and phosphorus response indicators, among other components of the Water Quality Standards rules under discussion.
Stressor identification/causal analysis approach: