40 CFR 131.11: States must adopt water quality criteria that protect designated uses. For waters with multiple uses, the criteria must protect the most sensitive use. 40 CFR 131.11(b)(1)(ii) authorizes states to adopt numeric water quality criteria that are “modified to reflect site-specific conditions.”
40 CFR 131.20: Revision of state water quality standards is subject to public participation procedures and U.S. EPA review and approval under 40 CFR 131.20. Wisconsin has authority under s. 281.15, Stats., to promulgate and revise water quality standards. Promulgation of site-specific criteria methodology would provide consistency with the federal regulations in 40 CFR 131.6 and 131.11 that require that criteria be based on protecting the designated uses of a waterbody. 7. Comparison with Similar Rules in Adjacent States:
Iowa, Indiana, Michigan and Ohio do not have statewide numeric phosphorus criteria. However, Michigan widely applies a method to derive appropriate site-specific phosphorus targets for waterbodies in the state. Ohio has a longstanding approach for developing site-specific phosphorus targets using a weight of evidence approach based on several eutrophication indicators. The targets set by Michigan and Ohio are applied in TMDLs and permits.
Illinois has adopted partial phosphorus criteria for lakes and reservoirs. Illinois does not have provisions for site-specific criteria.
Minnesota has adopted phosphorus criteria for lakes, reservoirs, rivers and streams. Minnesota allows specific water quality standards, referred to as SSC in Wisconsin, to be adopted when appropriate if information is available to derive standards based on a waterbody’s specific characteristics. This process is outlined in Minn. R. 7050.0220 and 7050.0222. Site-specific standards must maintain and protect a waterbody’s beneficial uses. Several site-specific phosphorus criteria have been approved in Minnesota.
8. Summary of Factual Data and Analytical Methodologies Used and How Any Related Findings Support the Regulatory Approach Chosen:
This rule is largely procedural in nature. The Department worked with U.S. EPA and Department water quality standards staff and attorneys to determine the type of information and data necessary to develop an SSC that would be approvable under state and federal regulations. The Department worked with these parties and an external stakeholder committee to develop a process for submittal and review of that information.
9. Analysis and Supporting Documents Used to Determine the Effect on Small Business or in Preparation of an Economic Impact Report:
Because this rule simply clarifies and documents a process for conducting a review already expressly allowed by state statutes and recognized in existing code, the creation of this rule is not expected to incur costs. The processes outlined in this rule are similar to those that the Department has followed under the existing rule, NR 102.06(7) and s. 281.15, Stats. The Department recognizes that during the SSC development process, a person requesting an SSC is likely to incur some costs for monitoring or modeling, but it is their choice whether to request an SSC and incur those costs. Also, by specifying the type of demonstration that needs to be made to support an SSC, the rule may save requestors costs and time by streamlining their study design and reducing the time needed for SSC approval. Once an SSC is developed for a waterbody, there may be alterations to WPDES (Wisconsin Pollutant Discharge Elimination System) permit limits for point source discharges at, or upstream of, these specific surface water segments. However, these are no different from any adjustments that would happen under SSC developed following the rulemaking process. This process is expected to be applicable to a relatively small proportion of waterbodies. However, the number of waterbodies in the state that may be eligible for SSC, or for which the permittees or other entities would be interested in pursuing an SSC, is unknown.
10. Effect on Small Business (initial regulatory flexibility analysis): As discussed above, this rule is not expected to incur costs other than those that would be incurred under the existing rule.
11. Agency Contact Person:
Kristi Minahan, Wisconsin Department of Natural Resources, Bureau of Water Quality WY/3, P.O. Box 7921, Madison, WI 53707-7921; Kristi.Minahan@Wisconsin.gov; 608-266-7055 12. Place where comments are to be submitted and deadline for submission:
Written comments may be submitted at the public hearings, by regular mail, or email to:
Kristi Minahan
Department of Natural Resources
Bureau of Water Quality – WY/3
PO Box 7921
Madison WI 53707
608-266-7055
Madison: Department of Natural Resources, 101 S. Webster St., Madison, WI 53707, Room G09
Green Bay: DNR Service Center, 2984 Shawano Ave, Green Bay WI 54313, Lake Michigan Room
Section 1 NR 102.01 (1) is amended to read:
NR 102.01 Purpose. (1) The purpose of this chapter is to establish, in conjunction with chs. NR 103 to 105, water quality standards for surface waters of the state pursuant to s. 281.15, Stats. This chapter describes the designated use categories for such waters and the water quality criteria necessary to support these uses. This chapter and chs. NR 103 to 105chapter, chs. NR 103 to 105, and 119 constitute the water quality standards for the surface waters of Wisconsin. Section 2. NR 102.06 (7) is amended to read:
NR 102.06 (7) Site-specific criteria. A criterion contained within this section may be modified by rule for a specific surface water segment or waterbody. A site-specific criterion may be adopted in place of the generally applicable criteria in this section where site-specific data and analysis using scientifically defensible methods and sound scientific rationale demonstrate a different criterion is protective of the designated use of the specific surface water segment or waterbody. Procedures for developing site-specific criteria for phosphorus are established in ch. NR 119. Section 3. NR 119 is created to read:
PHOSPHORUS SITE-SPECIFIC WATER QUALITY CRITERIA
NR 119.01 General. This chapter establishes standard protocols for developing site-specific water quality criteria for total phosphorus. A phosphorus site-specific criterion may be established to appropriately protect a waterbody’s designated uses when the applicable statewide total phosphorus criterion, as specified in s. NR 102.06, is determined by the department to be more or less stringent than necessary to protect the uses of the waterbody due to site-specific conditions. The requirements specified in s. 281.15 (1) and (2) (b) to (e), Stats., shall be met when developing a site-specific criterion under this chapter. Protection of a waterbody’s designated uses is evaluated using indicators of the ecosystem’s response to phosphorus and overall biotic integrity. After a phosphorus site-specific criterion is adopted, approved by the U.S. environmental protection agency, and takes effect, it becomes the applicable water quality criterion under s. 281.15, Stats., for the approved waterbody or segment. NR 119.02 Definitions. In this chapter the following definitions apply:
(1) “Biocriterion” means a surface water quality criterion under subch. III of ch. NR 102 that describes the structure and function of aquatic communities in a waterbody necessary to protect its designated aquatic life use. (2) “Clean Water Act” or “CWA” means the federal Clean Water Act of 1972 and amendments.
(3) “Designated uses” are the uses assigned to Wisconsin’s waterbodies as specified in s. NR 102.04. Note: Pursuant to the Clean Water Act, all of Wisconsin’s surface waters are assigned to the following use categories: aquatic life, recreation, public health and welfare, wildlife.
(4) “Less stringent SSC” means a site-specific phosphorus criterion that is established at a concentration higher than a waterbody’s statewide phosphorus criterion.
(5) “More stringent SSC” means a site-specific phosphorus criterion that is established at a concentration lower than a waterbody’s statewide phosphorus criterion.
(6) “Natural background phosphorus concentration” means the phosphorus concentration from natural sources, including forested and undeveloped lands, and from natural processes such as weathering and dissolution, that would exist in the absence of measurable impacts from human activity or influence.
(7) “Phosphorus response indicator” means an indicator and its thresholds, as specified in s. NR 102.07 (4) to (7), that characterize the condition or abundance of aquatic organisms that are responsive to phosphorus. (8) “Section 303(d) list” means a list of waters that do not attain water quality standards and require a total maximum daily load analysis, as specified in Section 303(d) of the Clean Water Act.
(9) “Site-specific criterion” or “SSC” means a phosphorus criterion applicable to a waterbody or segment that differs from the statewide phosphorus criterion due to specific conditions at the waterbody or segment, documented using data for the specific site or a similar reference site.
(10) “Statewide phosphorus criterion” means the statewide phosphorus surface water quality criterion specified in s. NR 102.06 that applies to a specific waterbody in absence of an adopted, approved, and effective site-specific criterion. (11) “Strahler stream order” is a numerical hierarchy of stream segments increasing from headwaters through downstream reaches.
(12) “Total maximum daily load” or “TMDL” has the meaning defined in s. NR 212.72 (11). (13) “U.S. EPA” means the United States environmental protection agency.
(14) “Weather-controlled ambient total phosphorus concentration” has the meaning defined in s. NR 102.06 (2) (k). (15) “WPDES permit” means a Wisconsin pollutant discharge elimination system permit issued by the department under ch. 283, Stats. NR 119.03 Less stringent SSC. A waterbody or segment may be eligible for an SSC that is less stringent than the statewide phosphorus criterion if the requestor demonstrates and the department determines that the designated uses of the waterbody and its affected downstream waters can be protected by a less stringent phosphorus criterion based on the analysis of site-specific data. For the department to approve a less stringent SSC, the SSC shall be developed using methods specified in ss. NR 119.05 to 119.06 and be protective of downstream uses as specified in s. NR 119.06 (6). The categories of waterbodies that may qualify for less stringent SSC include all of the following: (1) Biological metrics attained. A less stringent SSC may be appropriate for a waterbody that is not attaining its statewide phosphorus criterion if all of its phosphorus response indicators and biocriteria are attained.
(2) Biological metrics not attained. A less stringent SSC may be appropriate for a waterbody that is not attaining its statewide phosphorus criterion even if one or more of its phosphorus response indicators or biocriteria are not attained, provided a modeling analysis demonstrates that the phosphorus response indicators are expected to be attained if the waterbody’s phosphorus concentration is sufficiently reduced to attain a proposed SSC that is less stringent than the statewide phosphorus criterion.
Note: Certain reservoirs with a statewide phosphorus criterion of 30-40 ug/L may fit in this category. An example of this analysis is the modeling and analysis conducted for Petenwell and Castle Rock Lakes.
(3) High natural background phosphorus concentration. A less stringent SSC may be appropriate if a waterbody is not attaining the statewide phosphorus criterion because the natural background phosphorus concentration is higher than the statewide phosphorus criterion.
NR 119.04 More stringent SSC. A waterbody or segment is eligible for an SSC that is more stringent than the statewide phosphorus criterion if the requestor demonstrates and the department determines that the statewide phosphorus criterion is not sufficiently protective of the waterbody’s designated uses. A more stringent SSC may be appropriate if a waterbody is in one of the following categories:
(1) Biological metrics not attained. A more stringent SSC may be appropriate if a waterbody attains its statewide phosphorus criterion but does not attain one or more of its phosphorus response indicators or biocriteria. A more stringent SSC is not appropriate under this paragraph if a biocriterion or phosphorus response indicator is not attained due to reasons other than phosphorus.
Note: Because flowing waters may transport algae downstream from where it is produced, an SSC should only be established on the segment of the waterbody where the impairment is being generated. For example, if a river directly downstream of an impoundment attains its phosphorus criterion but receives high algae concentrations passed through from the impounded area, a more stringent SSC for the river segment downstream from the dam may not be appropriate since the source of the algae is upstream. Establishing an SSC downstream from the dam is not likely to achieve attainment of the phosphorus response indicator.
(2) Biological metrics attained. A more stringent SSC may be appropriate even if a waterbody attains its statewide phosphorus criterion, phosphorus response indicators, and biocriteria in cases when it is demonstrated that a more stringent SSC than the statewide phosphorus criterion is necessary to maintain attainment of any of these indicators and the level necessary can be demonstrated through modeling.
Note: Certain impounded flowing waters with a statewide phosphorus criterion of 100 ug/L may fit in this category.
NR 119.05 Methods for determining an SSC. An SSC shall be developed using one of the following methods:
(1) SSC based on ambient phosphorus concentration. For cases under s. NR 119.03 (1) when it is demonstrated that a less stringent SSC is appropriate because biological metrics are attained, the department may set the SSC at a concentration not to exceed a flowing water’s median ambient concentration, or a lake or reservoir’s mean ambient phosphorus concentration. If the weather-controlled ambient total phosphorus concentration can be determined for the waterbody, this value may be used as the ambient phosphorus concentration. Note: The SSC is set at the waterbody’s weather-controlled ambient phosphorus concentration because the long-term ambient concentration is deemed to be protective of designated uses if the waterbody attains its phosphorus response indicators and biocriteria at current concentrations.
(2) SSC derived through modeling. (a) Modeling analysis. If a statistical or modeling analysis demonstrates that attaining a phosphorus concentration higher or lower than the statewide phosphorus criterion will attain a waterbody’s suspended chlorophyll a phosphorus response indicators specified in s. NR 102.07 (4) (a) to (b) and (5), the department shall set the SSC at the modeled phosphorus concentration expected to attain the applicable indicators. The analysis shall be conducted following requirements specified in s. NR 119.06 (4) (b).
