The statement of scope for this rule, SS 001-14, was approved by the Governor on December 19, 2013, published in Register No. 697A on January 14, 2014, and approved by the Natural Resources Board on February 26, 2014. This rule was approved by the Governor on February December 20, 2019. ORDER OF THE STATE OF WISCONSIN NATURAL RESOURCES BOARD
REPEALING, RENUMBERING, RENUMBERING AND AMENDING, AMENDING, REPEALING AND RECREATING AND CREATING RULES
The Wisconsin Natural Resources Board adopts an order to repeal NR 102.04 (4) (b) and 102.06 (7) (Note 2); to renumber NR 102.06 (2) (a), (f), (fm), and (j); to renumber and amend NR 102.06 (2) (g), (i), and (4) (c); to amend NR 102.03 (intro.), 102.04 (4) (d) and (5) (b), 102.06 (1) and (2) (intro.), and 217.13 (2) (d) and (Note); to repeal and recreate NR 102.04 (4) (a) and 102.06 (3) (title); and to create NR 102.03 (1c), (1e), (1g), (1i), (1k), (1m), (1q), (1v), (6), and (6s) (Note), 102.04 (4) (am) and (f), 102.07, and 102 Subchapter III, relating to processes for waterbody assessments, biological assessment thresholds, biological confirmation of phosphorus impairments, and water quality criteria for dissolved oxygen. |
WY-23-13
Analysis Prepared by the Department of Natural Resources
1-3. Statutory Authority, Statutes Interpreted, and Explanation of Agency Authority:
Sections 281.11 and 281.12, Wis. Stats., grant necessary powers and establish a comprehensive program under the WDNR to enhance quality management and protection of all waters of the state. It grants the WDNR general supervision and control to carry out the planning, management and regulatory programs necessary for prevention/reduction of water pollution and for improvement of water quality.
Section 281.13, Wis. Stats., grants the department authority to research and evaluate the quality and condition of the state’s natural water sources.
Section 281.15, Wis. Stats. mandates that the department promulgate water quality standards, including water quality criteria and designated uses. It recognizes that different use categories and criteria are appropriate for different types of waterbodies, and that the department shall establish criteria which are not more stringent than reasonably necessary to assure attainment of the designated use for the water bodies in question.
Section 281.65(4)(c) and (cd), Wis. Stats., directs the department to prepare a list of waters impaired by nonpoint source pollution. 4. Related Statutes or Rules:
The proposed rules are related to one other rule package currently in progress. Rule package WT-17-12 creates processes for establishing site-specific criteria for phosphorus. A waterbody’s eligibility for a site-specific criterion under that rule is largely dependent on whether the waterbody is attaining its phosphorus response indicators and biological assessment thresholds as specified in this rule package. Material created as part of this rule package is cross-referenced in the draft site-specific criteria rule. Therefore this rule package, WY-23-13, must be promulgated before or concurrent with rule package WT-17-12.
5. Plain Language Analysis:
This rule package addresses several areas related to the state’s assessments of its streams, rivers, lakes and other waterbodies. It focuses largely on assessments related to the biological quality of a waterbody.
Waterbody Assessments and Reporting. Every two years, under federal Clean Water Act requirements, the department assesses the state’s waterbodies to determine whether they are attaining water quality standards. A new subchapter is proposed that codifies Wisconsin’s current procedures for conducting surface water assessments, including public participation opportunities and U.S Environmental Protection Agency (U.S. EPA) approval. This Board Order contains amendments requested by the Joint Committee for Review of Administrative Rules on May 17, 2022, clarifying that only water quality standards that have been promulgated via statute or rule may be considered for the purposes of listing a waterbody on the section 303(d) list, also known as the impaired waters list.
Biological assessment thresholds. The most direct and commonly-applied method of measuring the quality of a waterbody is through assessing the biological communities within the waterbody—its fish, insects, plants, and algae. The proposed rule establishes biological assessment thresholds that are used to evaluate the biological health of surface waters in the state. The proposed “Waterbody Assessments and Reporting” subchapter includes the following sections related to biological assessments:
Narrative biological assessment thresholds. Narrative thresholds set expectations and goals for the biological quality of these communities. They are used to measure the quality of a waterbody’s biological community and to determine attainment of its designated uses. This section also generally describes the types of biological assessments that have been conducted by the department to determine whether a waterbody’s aquatic community is considered healthy and attaining its designated uses.
Numeric biological assessment thresholds for lakes, reservoirs, and impounded flowing waters. Numeric thresholds set benchmarks that indicate attainment of a lake or reservoir’s designated uses. Once a numeric biological assessment threshold is codified by rule, it cannot be revised unless the rule is revised. These thresholds include:o
Algae thresholds for Recreation and Aquatic Life. The rule proposes algae (chlorophyll a) thresholds for lakes, reservoirs and impounded flowing waters. Algae levels are a top water quality concern for the public, and are a critical component of waterbody assessments to determine whether recreational goals are met. The chlorophyll a thresholds created in the proposed rule are the same considerations that have been used by the department to assess water quality for recreation and aquatic life uses. A minor exception to this is the aquatic life chlorophyll a threshold for two-story fishery lakes, which is lowered slightly from the previous recommended goal of 10 ug/L to a new codified threshold of 8 ug/L chlorophyll a, but this affects very few waters. o
Aquatic plant thresholds for aquatic life. The rule includes numeric thresholds for aquatic plants in lakes and reservoirs. These thresholds indicate attainment of healthy plant communities within lakes, an important factor in lake habitat to support aquatic life.
Phosphorus assessment procedures using biological metrics. Statewide phosphorus water quality standards were promulgated by rule in 2010. However, the rule did not include evaluation procedures for determining attainment of the phosphorus standard in a waterbody (e.g. evaluating criteria exceedances and impacts to biological community). This rule specifies how attainment of the numeric phosphorus criteria is determined. It also incorporates flexibility for evaluating phosphorus surface water impairments by creating a “combined assessment” approach. Under this approach, the waterbody’s phosphorus concentration is reviewed in conjunction with “phosphorus response indicators”—algae and plant metrics—that specifically indicate whether the waterbody is exhibiting a biological response to phosphorus. If a waterbody exceeds the statewide phosphorus criterion (within a specified range) but does not exhibit a biological or recreational use impairment, it would not be considered impaired for purposes of section 303 (d) listing.Dissolved oxygen criteria for Aquatic Life. Revisions to the existing dissolved oxygen criteria clarify which criteria apply to different waterbody types:
This rule specifies that the dissolved oxygen criterion of 7.0 mg/L applies not only to the time of spawning but also during the early life stages that require higher oxygen levels. This more protective time frame applies to only trout class I and II streams, which by definition support trout reproduction. This rule removes the requirement for higher dissolved oxygen during spawning from class III trout streams, which by definition do not support reproduction.
This rule relocates certain dissolved oxygen criteria from ch. NR 104 to s. NR 102.04(4), Wis. Adm. Code, so that all dissolved oxygen criteria are located in the same part of the code. The relocated criteria are the existing dissolved oxygen criterion of 3 mg/L for limited forage fish waters and 1 mg/L for limited aquatic life waters, diffuse surface waters, and wastewater effluent channels.
The addition of oxythermal criteria for two-story fisheries is necessary because the existing dissolved oxygen criteria are not appropriate for this relatively rare and sensitive type of coldwater fishery, comprising only 1% of Wisconsin’s lakes. Chapter NR 217, Wis. Adm. Code, calculation of upstream background phosphorus concentrations. This rule includes a revision to a portion of ch. NR 217, Wis. Adm. Code, to align the phosphorus calculation methods used to determine background phosphorus concentrations for effluent limit calculations with those delineated in proposed s. NR 102.07 (1) (b) to (c), Wis. Adm. Code. Previously, slightly different methods were used to calculate ambient phosphorus concentrations for purposes of criteria assessment and to calculate upstream background phosphorus concentrations for Wisconsin Pollutant Discharge Elimination System (WPDES) permit limit derivation under s. NR 217.13 (2) (d), Wis. Adm. Code. Although these two methods yield very similar resulting phosphorus concentrations, the differences between the two methods have caused confusion and are unnecessary. The proposed procedure detailed in s. NR 102.07 (1) (b) to (c), Wis. Adm. Code, will be most appropriate for both applications. Definitions. Several new definitions are included in this rule, and some definitions are relocated from the section of the rule dealing only with the phosphorus criteria to the section of the rule applying to the whole chapter. There are also some clarifications made to a few definitions, such as “stratified lake or reservoir” and “stratified two-story fishery lake.” These are not expected to change the waterbodies included in these categories, only to clarify the existing interpretation of these terms.
6. Summary of, and Comparison with, Existing or Proposed Federal Statutes and Regulations:
Federal regulations require that states assess surface waters and create an impaired waters list every two years. In addition, federal regulations require states to develop water quality criteria. However, federal regulations do not specify detailed procedures for assessing waters or listing them as impaired. This rule package establishes a general structure that the department follows in assessing surface waters and reporting under ss. 303 (d) and 305 (b) of the Clean Water Act, including listing waters on the impaired waters list. It also creates new biological assessment thresholds and water quality criteria to address the state’s water quality needs, including numeric thresholds for algae and aquatic plants, general narrative biological thresholds, phosphorus response indicators, oxythermal criteria for two-story fishery lakes, and updates to the existing dissolved oxygen criteria.
Sec. 303 (d) (1) (A) of the Federal Water Pollution Control Act (Clean Water Act) requires states to develop an impaired waters list that identifies waters that are not meeting any water quality standard.
Sec. 305 (b) (1) of the Federal Water Pollution Control Act (Clean Water Act) requires states to prepare a biennial report documenting which waterbodies are attaining their designated uses.
40 CFR s. 130.4 Water Quality Monitoring. This section requires water quality monitoring and assessments of state waters.
40 CFR s. 130.7 Total maximum daily loads (TMDLs) and individual water quality-based effluent limitations. This section provides additional information related to requirements for developing the impaired waters list.
40 CFR s. 130.8 Water Quality Reports. States must submit water quality reports to EPA that include a water quality assessment of state waters.
40 CFR s. 130.3. Water quality standards. This section defines water quality standards as setting water quality goals for a waterbody that will protect its designated uses (such as protection of fish, wildlife, recreation, and public health and welfare). Criteria will be set to protect those uses.
40 CFR s. 131.11 Criteria. States must adopt those water quality criteria that protect the designated use. Such criteria must be based on sound scientific rationale and must contain sufficient parameters or constituents to protect the designated use. For waters with multiple use designations, the criteria shall support the most sensitive use. 7. Comparison with Similar Rules in Adjacent States:
All states follow assessment procedures similar to the department’s general waterbody assessment procedures outlined in subch. III of ch. NR 102, Wis. Adm. Code.
Biological assessments are used by states to evaluate the biological health of surface waters and the results of assessments are summarized in biennial reports that are submitted to U.S. EPA. Some states assess waterbodies through guidance and other states have established narrative or numeric biological thresholds or criteria in rules. Narrative biological assessment thresholds provide a general statement of goals and the types of metrics that an agency uses to evaluate the biological health (quality of fish, insects, plants, or other aquatic life) of a waterbody, while numeric biological assessment thresholds specify numeric benchmarks that an agency uses to evaluate a waterbody’s biological health. Wisconsin is proposing both narrative and numeric biological assessment thresholds. Under Wisconsin’s proposed structure, these will be part of the state’s assessment protocols but will not be considered water quality criteria, as they are in some other states. Indiana currently has narrative biocriteria. Until recently, Minnesota had narrative biocriteria but recently revised their biocriteria to a numeric format. Ohio also has promulgated numeric biocriteria. Michigan, Illinois, and Iowa have not formally incorporated narrative or numeric biocriteria into their water quality standards. However, all Region 5 states, Iowa, and most other states in the nation do use biological metrics such as fish and insect scores for waterbody assessments and section 303 (d) listing, regardless of whether narrative or numeric thresholds or biocriteria are codified. Pursuant to 33 USC s. 1315, states are required to report on the biological health of surface waters every two years.
Most Region 5 states use some variation on phosphorus response indicators, including algal indicators or criteria. Minnesota has a promulgated combined criteria approach to assessing nutrient levels and their biological and chemical responses. Minnesota’s biological metrics center on chlorophyll a. Ohio’s approach is to use a multi-metric scoring system that aggregates results from separate evaluations of primary productivity (algae/plants), biological health and in-stream nutrient concentrations. Indiana has a process for assessing phosphorus impairments using chlorophyll a response indicators. Illinois has numeric phosphorus criteria for lakes and is currently considering promulgating proposed numeric phosphorus criteria for streams/rivers. Illinois also has narrative nutrient criteria and considers a water to be not meeting the criteria if excess algae is present in the waterbody. Michigan does not currently have numeric phosphorus criteria, but does have narrative phosphorus criteria. Iowa does not currently have phosphorus criteria but does assess waterbodies for phosphorus and chlorophyll a, and uses chlorophyll a to list waters as impaired for eutrophication based on narrative criteria.
Wisconsin, Minnesota, Michigan and Indiana are the main states in EPA Region 5 that have two-story fishery lakes supporting coldwater fish. Wisconsin’s oxythermal criteria were developed using a modification of methods developed in Minnesota. Although Minnesota uses its methods for assessments, it has not yet codified oxythermal criteria for its two-story fishery lakes. Minnesota and Indiana have general dissolved oxygen and temperature criteria for cold waters, though they do not distinguish between lakes and streams. Michigan has dissolved oxygen criteria specific to lakes with coldwater fish. These criteria generally require maintenance of at least 7 mg/L dissolved oxygen within the lake at varying depths, depending on certain lake characteristics. Michigan’s temperature criteria for all inland lakes also apply to coldwater lakes and, among other provisions, do not allow decreases in the volume of the thermocline/hypolimnion.
