Chapter NR 216

NR 216.008 Note Note: An example of other environmental impacts under subd. 2. d. would be a proposed discharge treatment alternative that would also increase or decrease impacts to air quality. An applicant may indicate whether regulations for other departmental environmental programs will be met under their proposal, and may include information about other positive environmental impacts.

NR 216.008(8)(c)2.e. e. Evaluation of the cost for each of the practicable alternatives under subd. 2. a. and b.

NR 216.008(8)(c)2.f. f. Any additional information or analysis of specific alternatives that the department determines necessary to assess the submitted social importance analysis or economic importance analysis under subd. 1. and alternatives analysis under this subdivision.

NR 216.008(8)(d) (d) Performance standards. The applicant shall submit information demonstrating that the respective requirements of this chapter and the performance standards and prohibitions of ch. NR 151 are met. The department shall impose additional permit conditions to address instances when the specific categories of a receiving water or specific characteristics of a regulated discharge require a permittee to incorporate additional practices to demonstrate that antidegradation requirements are met.

NR 216.008(8)(e) (e) Amendments.

NR 216.008(8)(e)1. 1. In this paragraph, “administrative operational changes” means changes to SWPPP contacts, changes to storm water management program contacts, and other administrative changes that do not result in a change in the operation of a site that would affect the quality or level of pollutant reduction a program would achieve.

NR 216.008(8)(e)2. 2. Except for administrative operational changes, if a permittee proposes an amendment to a SWPPP, an amendment to plans under s. NR 216.50, or changes to storm water management programs required under s. NR 216.07 (4) to (6) that would result in a discharge of a pollutant in excess of levels previously addressed by the programs, the permittee shall provide information to the department that demonstrates the amendment meets the conditions of the permit.

NR 216.008(9) (9) Department antidegradation review and determination for individual permits. The department shall apply the antidegradation policy under s. NR 102.045 and shall conduct an antidegradation review for each new or increased discharge seeking coverage under an individual WPDES permit issued under this chapter where the department has determined under sub. (7) (e) there is potential to lower water quality in a high quality water and the department determines that such a lowering may be permissible under sub. (8). The department shall condition individual permits to meet the antidegradation policy. The department shall follow the antidegradation review procedures as follows:

NR 216.008(9)(a) (a) Antidegradation review. If, after review of available information, the department finds that the proposed discharge will lower water quality in a high quality receiving or downstream water, the department shall only authorize lowering of the receiving or downstream water quality if the department finds that all of the following are met:

NR 216.008(9)(a)1. 1. The reduction of water quality meets the applicable water quality criteria to protect existing and designated uses under chs. NR 102 to 105.

NR 216.008(9)(a)2. 2. If the proposed discharge will lower water quality in a high quality water identified under s. NR 102.045 (2) (b) 1. to 3., each applicable requirement to protect a high quality water under sub. (8) (a) to (d) is met.

NR 216.008(9)(a)3. 3. If required under sub. (8) (c), the social importance analysis or economic importance analysis demonstrates that a lowering of water quality is necessary to accommodate important social or economic development in the area of the discharge.

NR 216.008(9)(a)4. 4. If required under sub. (8) (c), the alternatives analysis demonstrates that all of the following are met:

NR 216.008(9)(a)4.a. a. A lowering of water quality under the antidegradation policy is necessary under sub. (8) (c) 2. a.

NR 216.008(9)(a)4.b. b. When the analysis of alternatives identifies one or more practicable alternatives that the department determines will effectively lessen degradation from the proposed activity, one of these alternatives is selected for implementation. If degradation can be lessened through implementation of best management practices, the department may find that those methods are acceptable as the practicable alternative.

NR 216.008(9)(a)5. 5. If an alternative meeting the requirements under sub. (8) (c) 2. is approvable by the department, permit conditions used in the preliminary antidegradation determination shall reflect a less degrading alternative selected, or if there is no degradation to the receiving water, the preliminary antidegradation determination shall reflect that there is no lowering of water quality.

NR 216.008(9)(a)6. 6. Point source and state-regulated nonpoint source discharges to the receiving water will meet requirements of the antidegradation policy under s. NR 102.045 (5) (c), as determined under sub. (7) (d).

NR 216.008(9)(a)7. 7. The antidegradation policy and procedures under this subchapter have been applied consistent with section 316 (a) of the Clean Water Act, 33 USC 1326 (a), with regard to potential thermal discharge impairments.

NR 216.008(9)(a)8. 8. The requirements under this chapter related to water quality and the performance standards and prohibitions under ch. NR 151 are met.

NR 216.008(9)(b) (b) Preliminary antidegradation determination.

NR 216.008(9)(b)1. 1. Based upon the antidegradation review described under par. (a), the department shall prepare a written draft antidegradation determination as to whether the antidegradation policy under s. NR 102.045 has been satisfied.

NR 216.008(9)(b)2. 2. If the department finds that the antidegradation policy is not satisfied, the department shall provide written notification to the applicant identifying the reasons for this determination and shall provide the applicant the opportunity to modify the application to meet the requirements under sub. (8).

NR 216.008(9)(c) (c) Opportunity for comment. The department shall do all of the following to solicit public input on the preliminary antidegradation determination:

NR 216.008(9)(c)1. 1. Include the draft antidegradation determination with the public notice regarding the WPDES permit according to s. NR 203.02.

NR 216.008(9)(c)2. 2. Distribute the public notice according to subch. I of ch. NR 203.

NR 216.008 Note Note: The public notice process under subd. 2. also satisfies the state’s intergovernmental coordination provisions under s. 283.83 (1) (e), Stats.

NR 216.008(9)(c)3. 3. Provide opportunity for comment on the draft antidegradation determination.

NR 216.008(9)(d) (d) Final antidegradation determination. The department shall consider comments received under par. (c) before preparing a written final antidegradation determination. The final antidegradation determination shall include a statement of whether the proposed activity satisfies or fails to satisfy the antidegradation policy specified under s. NR 102.045 and implementation requirements in this section. The final antidegradation determination shall be included with the department’s notice of final determination regarding the WPDES permit under s. NR 203.13.

NR 216.008 History History: CR 23-010: cr. Register January 2026 No. 841, eff. 7-1-26; correction in (3) (k), (5) (b), (6) (a) (intro.), (f) 1., (7) (e) 1., (8) (c) 2. d., e., (d), (e), (9) (b) 2. made under s. 35.17, Stats., Register January 2026 No. 841.

subch. I of ch. NR 216 Subchapter I — Municipal Storm Water Discharge Permits

NR 216.01 NR 216.01 Purpose. The purpose of this subchapter is to identify municipalities that are required to obtain WPDES municipal storm water permits, and to establish the application and permit requirements for municipal storm water discharge permits, as required by s. 283.33, Stats. The goal of this subchapter is to address storm water quality concerns associated with urban runoff and prevent to the maximum extent practicable the discharge of pollutants from municipal separate storm sewer systems as identified in s. NR 216.02. The department shall consider other environmental problems facing municipalities and emphasize cost effective best management practices when determining what is practicable.

NR 216.01 History History: CR 03-028: cr. Register July 2004 No. 583, eff. 8-1-04.

NR 216.02 NR 216.02 Permit coverage required. The following owners or operators of municipal separate storm sewer systems shall obtain coverage under a WPDES municipal storm water permit under this subchapter:

NR 216.02 Note Note: A city, village or town is not responsible for a county, state and federally operated MS4 that lies within its jurisdiction.

NR 216.02(1) (1) Owners and operators of municipal separate storm sewer systems serving populations of 100,000 or more. The owner or operator of a municipal separate storm sewer system serving incorporated areas with a population of 100,000 or more as determined by the 1990 decennial census.

NR 216.02(2) (2) Previously notified owners or operators of municipal separate storm sewer systems. The owner or operator of a municipal separate storm sewer system notified in writing by the department prior to August 1, 2004, to obtain a WPDES municipal storm water permit.

NR 216.02(3) (3) Urbanized areas. Unless exempted pursuant to s. NR 216.023, the owner or operator of a municipal separate storm sewer system within an urbanized area as defined by the U.S. bureau of the census.

NR 216.02(4) (4) Municipal separate storm sewer systems serving over 10,000. An owner or operator of a municipal separate storm sewer system serving a population of 10,000 or more and a population density of 1,000 or more per square mile, as determined by the U.S. bureau of the census based on the latest decennial census unless it is exempted under s. NR 216.024.

NR 216.02 History History: CR 03-028: cr. Register July 2004 No. 583, eff. 8-1-04.

NR 216.023 NR 216.023 Urbanized area exemption. The department may waive the requirement to obtain permit coverage under this subchapter for a municipal separate storm sewer system within an urbanized area listed under s. NR 216.02 (3) that meets all of the following:

NR 216.023(1) (1) The owner or operator of the system is not otherwise required to obtain permit coverage pursuant to s. NR 216.02 (2).

NR 216.023(2) (2) The system serves a population less than 1,000.

NR 216.023(3) (3) The system is not contributing substantially to the pollutant loadings of a physically interconnected municipal separate storm sewer system that is regulated under this subchapter.

NR 216.023(4) (4) If the system discharges a pollutant that has been identified as a cause of impairment of any water body to which it discharges, storm water controls must not be needed based on wasteload allocations that are part of a U.S. EPA approved or established TMDL that addresses any pollutant of concern.

NR 216.023 Note Note: The department has a list of impaired waters with pollutants of concern available on its website. If an MS4 is exempted from permit coverage under this section, the owner or operator does not need to satisfy the exemption requirements of s. NR 216.024.

NR 216.023 History History: CR 03-028: cr. Register July 2004 No. 583, eff. 8-1-04.

NR 216.024 NR 216.024 Non-urbanized area exemption.

NR 216.024(1) (1) The owner or operator of a municipal separate storm sewer system required to have permit coverage under s. NR 216.02 (4) may request that its municipal separate storm sewer system be exempted by the department from the requirement to obtain permit coverage under this subchapter. This request shall demonstrate all of the following:

NR 216.024(1)(a) (a) The municipal separate storm sewer system is not required to have permit coverage pursuant to s. NR 216.02 (1), (2) or (3);

NR 216.024(1)(b) (b) The municipal separate storm sewer system receives runoff from less than 320 total acres from any combination of the following land uses including all pervious and impervious land covers such as roof tops, parking lots, roads, sidewalks and grassed areas:

NR 216.024(1)(b)1. 1. Commercial.

NR 216.024(1)(b)2. 2. Industrial.

NR 216.024(1)(b)3. 3. Institutional.

NR 216.024(1)(b)4. 4. Residential with greater than 4.0 homes per acre.

NR 216.024(1)(c) (c) The rate of population growth of the area served by the municipal separate storm sewer system is less than 10% between the 2 most recent decennial censuses as determined by the U.S. bureau of the census.

NR 216.024(1)(d) (d) The municipal separate storm sewer system does not discharge directly into any outstanding resource water listed under s. NR 102.10, exceptional resource water listed under s. NR 102.11, a cold water stream as listed under s. NR 102.04 (3) (a), Great Lakes area of concern pursuant to 33 USC 1268 or a wetland in an area of special natural resource interest as specified in s. NR 103.04.

NR 216.024(1)(e) (e) If the system discharges a pollutant that has been identified as a cause of impairment of any water body to which it discharges, storm water controls must not be needed based on wasteload allocations that are part of a U.S. EPA approved or established TMDL that addresses any pollutant of concern.

NR 216.024(2) (2) An exemption request under this section shall be made by the owner or operator of the municipal separate storm sewer system within 90 days of the department letter notifying the owner or operator to apply for permit coverage under this subchapter. The department letter shall indicate that the owner or operator has 90 days to submit an exemption request pursuant to this section. The exemption request shall be submitted to the department together with the application required under s. NR 216.03.

NR 216.024(3) (3) The department shall exempt the owner or operator of a municipal separate storm sewer system from the requirement to obtain permit coverage under this subchapter for requests that comply with subs. (1) and (2), unless either of the following occurs:

NR 216.024(3)(a) (a) The department has site-specific information that the municipal separate storm sewer system has a physical, chemical or biological impact that threatens or impairs the designated uses of waters of the state.

NR 216.024(3)(b) (b) The department has determined that controls are needed on the municipal separate storm sewer system based on wasteload allocations that are part of a U.S. EPA approved or established TMDL or equivalent analysis that addresses the pollutants of concern.

NR 216.024 History History: CR 03-028: cr. Register July 2004 No. 583, eff. 8-1-04.

NR 216.025 NR 216.025 Designation criteria. The department may require the owner or operator of any municipal separate storm sewer system to obtain permit coverage under this subchapter if the system meets any of the following:

NR 216.025(1) (1) It serves an area contiguous to an area served by a municipal separate storm sewer system that is required to have permit coverage under this subchapter and it receives runoff from 320 or more total acres from any combination of the following land uses including all pervious and impervious land covers such as roof tops, parking lots, roads, sidewalks and grassed areas:

NR 216.025(1)(a) (a) Commercial.

NR 216.025(1)(b) (b) Industrial.

NR 216.025(1)(c) (c) Institutional.

NR 216.025(1)(d) (d) Residential with greater than 4.0 homes per acre.

NR 216.025(2) (2) The department has site-specific information that the municipal separate storm sewer system has a physical, chemical or biological impact that threatens or impairs the designated uses of waters of the state.

NR 216.025(3) (3) The department determines that controls are needed on the municipal separate storm sewer system based on wasteload allocations that are part of a U.S. EPA approved or established TMDL or equivalent analysis that addresses the pollutants of concern.

NR 216.025 History History: CR 03-028: cr. Register July 2004 No. 583, eff. 8-1-04.

NR 216.026 NR 216.026 Petition for permit coverage. Any person may petition the department to evaluate a municipal separate storm sewer for the need to obtain permit coverage using the criteria under s. NR 216.025. The petition shall contain relevant information to assist the department in this evaluation in accordance with the criteria contained in s. NR 216.025. In response to a petition, the department may perform an evaluation of the municipal separate storm sewer system for which the petition is received.

NR 216.026 History History: CR 03-028: cr. Register July 2004 No. 583, eff. 8-1-04.

NR 216.03 NR 216.03 Application for permit coverage.

NR 216.03(1) (1) The owner or operator of a municipal separate storm sewer system identified as needing a permit under s. NR 216.02 shall submit an application under sub. (2) for coverage under a WPDES permit under this subchapter to the department within 90 days of a department letter notifying the owner or operator that a permit application is required. The application shall be submitted on forms made available from the department as specified under s. NR 216.006.

NR 216.03 Note Note: Application forms may be obtained from the department website at https://dnr.wisconsin.gov/topic/Stormwater/municipal or by calling 1-888-936-7463.

NR 216.03(2) (2) The owner or operator of a municipal separate storm sewer system identified as needing a permit under s. NR 216.02 shall submit a permit application to the department requesting to be covered by one of the following methods:

NR 216.03(2)(a) (a) Under a general permit. Applications for coverage under a general permit shall be submitted in accordance with s. NR 216.031.

NR 216.03(2)(b) (b) Under an individual permit by themselves or as a co-applicant. Applications for coverage under an individual permit shall be submitted in accordance with s. NR 216.032.

NR 216.03(2)(c) (c) If the application for individual permit coverage includes one or more co-applicants, then all of the following apply:

NR 216.03(2)(c)1. 1. All owners or operators of municipal separate storm sewer systems that are interested in obtaining coverage under the permit shall be listed.

NR 216.03(2)(c)2. 2. The expected benefits of having individual permit coverage shall be described in the application.

NR 216.03(2)(d) (d) One application may be submitted by multiple owners or operators of municipal separate storm sewer systems when requesting to be covered as co-applicants under an individual permit.

NR 216.03 History History: CR 03-028: cr. Register July 2004 No. 583, eff. 8-1-04; CR 21-027: am. (1), (2) (a), (b) Register March 2022 No. 795, eff. 4-1-22.

NR 216.031 NR 216.031 General permit application requirements. Municipalities subject to the requirements of this subchapter seeking coverage under a general permit shall submit an application for permit coverage to the department. The contents of the application shall be specified in the general permit, shall require the submission of information necessary to demonstrate adequate program implementation, and at a minimum shall include all of the following:

NR 216.031(1) (1) General information.

NR 216.031(1)(a) (a) The legal name, address, and telephone number of the municipal owner or operator, and additional contact persons.

NR 216.031(1)(b) (b) Status as a government entity.

NR 216.031(1)(c) (c) Type of facility or discharges.