NR 140 Groundwater Quality Standards Update

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As part of a continuing commitment to protect public health and the environment, the DNR periodically updates groundwater quality standards in ch. NR 140, Wis. Adm. Code. Since its establishment in 1985, the Natural Resources Board has approved amendments to NR 140 twelve times in order to revise existing standards, establish new standards and clarify rule language.

About cycles

Under state groundwater law the DNR periodically submits a list of substances to the Wisconsin Department of Health Services (DHS) requesting that they review available toxicologic information and provide recommendations for new and/or revised groundwater standards. These lists submitted to DHS are known as NR 140 "cycle" lists. DHS then prepares a Scientific Support Document for the DNR which describes the information and methodology used to develop each recommended standard.

Recent recommendations

PFAS - In April of 2024, the U.S. Environmental Protection Agency (EPA) finalized federal drinking water standards under the Federal National Primary Drinking Water Regulation (NPDWR) for six Per- and Polyfluorinated Substances (PFAS): PFOA, PFOS, PFNA, PFHxS, HFPO-DA (GenX chemicals) and PFBS.

In May of 2024, the DNR sent a letter to DHS formally requesting that DHS recommend state groundwater quality enforcement standards for the six PFAS. After conducting a review of the six compounds, DHS developed appropriate recommendations for Cycle 12 groundwater quality standards based on statutory requirements. At the end of January 2025, the DNR received a letter from DHS with recommendations for the six PFAS. Following this, the DNR initiated the rulemaking process to establish groundwater standards for six PFAS (Cycle 12).

Rulemaking

Cycle 12 - PFAS (Started in 2025)

The DNR is in the early stage of the rule development and anticipates presenting the scope statement to the Natural Resources Board for approval in the spring of 2025.

Spring 2024 DNR letter sent to DHS - May 22, 2024
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Winter 2025 DHS letter sent to DNR - received on Jan. 30, 2025; revised on Feb. 7, 2025. Statement of Scope approved by DNR secretary, governor	←	We are here

PFAS (Started in 2022. Withdrawn in 2025)

The proposed DG-17-22 rule would have amended ch. NR 140, Wis. Adm. Code, to add new public health related groundwater standards for four per- and polyfluoroalkyl substances (PFAS): PFOA, PFOS, HFPO-DA (GenX chemicals) and PFBS.

This rule was withdrawn in February 2025, in light of new DHS recommendations on these four PFAS. The DNR has begun rulemaking based on the updated recommendations. For more information expand the Cycle 12-PFAS field above.

DG-17-22 PFAS rulemaking timeline

Fall 2022/Winter 2023 Statement of Scope approved by DNR secretary, governor Notice of preliminary public hearing on scope statement NRB scope approval - Dec. 14, 2022 Preliminary comments on scope statement
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Summer 2023 Preparation of proposed rule Solicitation of information for economic impact analysis (EIA) Stakeholder Meeting - July 14, 2023 Stakeholder Presentation Stakeholder Meeting Recording [54:28] Based on stakeholder feedback, the DNR returned to all four compounds included in the original scope instead of focusing only on two PFAS (i.e., PFOA and PFOS) as discussed at the July stakeholder meeting.
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Fall 2023 Draft Economic Impact Analysis Draft EIA public comment period - Sept. 28 - Oct. 28, 2023 Draft EIA comments Final EIA NOTE: Per ch. 227, Wis. Stats., the department was prohibited from further work on this rule until the legislature authorized the department to continue rulemaking.
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Winter 2025 The department withdrew scope statement SS 075-22 (Board Order DG-17-22), along with the related final economic impact analysis. DNR letter to Legislature - February 7, 2025	←	We are here.  Rule has been withdrawn.

Cycle 10 - Bacteria (Started in 2022. Approved in 2023)

These changes to the rule were published in the Administrative Register and became effective on Aug. 1, 2023. 

The proposed rule will amend ch. NR 140, Wis. Adm. Code, to replace the existing total coliform bacteria standards with new state groundwater quality standards for Escherichia coli (E. coli) bacteria. The proposed rule will also transition total coliform bacteria from a public health groundwater quality standard to an indicator parameter.

Cycle 10 Bacteria rulemaking timeline

Winter/Spring 2022 Statement of Scope approved by DNR secretary, governor Notice of preliminary public hearing on scope statement Preliminary comments on scope statement Video: Public Hearing
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NRB scope approval - May 25, 2022 Preparation of proposed rule Solicitation of information for economic impact analysis (EIA)
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EIA public comment period EIA comments
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Public hearing on proposed rule Draft Rule Fiscal Estimate & Economic Impact Analysis Public comment period
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NRB meeting for adoption - Jan. 25, 2023
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Rule approved by governor Legislative review/hearings Rule signed by DNR Secretary
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Rule published and effective - Aug. 1, 2023	←	We are here

 

Cycle 11 (Started in 2021. Expired in 2023)

The scope statement expired on Sept. 15, 2023. Any future rulemaking will take place under a new scope statement.

The DNR submitted a list of substances designated "Cycle 11" to DHS in April 2019. DHS responded with recommendations to DNR in November 2020. A plain language summary of each of the compounds in Cycle 11 is available at DHS's Groundwater Standards.

• Cycle 11 response letter from DHS to DNR: Summary of Cycle 11 Recommendations (Nov. 6, 2020)
• Cycle 11 letter from DNR to DHS: Request for State Groundwater Quality Standard Recommendations under ch. 160, Stats. (April 10, 2019)

Cycle 11 Rulemaking Timeline

Spring - Fall 2019 DNR letter sent to DHS - April 10, 2019 DNR letter sent to DHS - Sept. 18, 2019 DHS letter sent to DNR - Oct. 28, 2019 DNR letter sent to DHS - Nov. 8, 2019
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Fall 2020 DHS response to letter from DNR - Nov. 6, 2020
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Winter 2020/2021 - present Statement of Scope approved by DNR secretary, governor Notice of preliminary public hearing on scope statement June 4, 2021 Statement of Scope approved by NRB - June 23, 2021	←	We are here, scope statement expired
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Rule drafting Advisory workgroups
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Preparation of proposed rule
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Solicitation of information for economic impact analysis Draft of EIA and public hearings
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Public hearings on proposed rule NRB meeting for adoption Rule approved by governor
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Legislative review/hearings Rule signed by DNR Secretary
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Rule published and effective

Cycle 10 (Started in 2019. Not approved in 2022)

On Feb. 23, 2022, the Natural Resources Board considered and did not approve this rule. The scope statement expired on March 3, 2022. Any future rulemaking will take place under a new scope statement. See the Cycle 10 Bacteria tab.

The DNR submitted a list of substances designated "Cycle 10" to DHS in March 2018. DHS responded with recommendations to DNR in June 2019. Based on comments received during the rule public comment period, DHS has made revisions to their recommendations for Cycle 10 groundwater standards. The revisions to the DHS Cycle 10 recommendations are included in their revised scientific support documents below. A plain language summary of each of the compounds in Cycle 10 is available at DHS's Recommended Groundwater Enforcement Standards. The DATCP website contains additional information on the Cycle 10 pesticide compounds.

• DHS Revised Recommendations for Cycle 10 Groundwater Standards (Feb. 1, 2022)
• Cycle 10 response letter from DHS to DNR: Summary of Cycle 10 Recommendations (June 21, 2019)
• Cycle 10 letter from DNR to DHS: Request for Recommendations for State Groundwater Quality Standards (March 2, 2018)

Cycle 10 rulemaking timeline

Spring 2018 DNR letter sent to DHS - March 2, 2018
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Summer 2019 DHS response to letter from DNR - June 21, 2019
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Fall 2019 Statement of Scope approved by DNR secretary, governor Notice of preliminary public hearing on scope statement Nov. 12, 2019 Preliminary comments on scope statements Video: 11/12/19 Public Hearing
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Jan. 2020 - Winter 2020/2021 NRB scope approval Stakeholder group meetings - open to public Preparation of proposed rule Solicitation of information for economic impact analysis (EIA)
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Winter 2020 - Spring 2021 Stakeholder group meetings complete EIA public comment period EIA comments
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Winter 2021 Public hearing on proposed rule - Jan. 6, 2022 Public comment period - Dec. 6, 2021 - Jan. 11, 2022 View the Draft Rule
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Spring 2022 NRB meeting for adoption - Feb. 23, 2022 Action Item 4C Public Appearances Written Public Comments	←	NRB did not approve rule

Cycle 10 Stakeholder Meetings

Before final consideration by the NRB, there were numerous opportunities for the public to submit feedback about this proposed rule. Below is an archive of the public meetings and materials shared with the public during this rulemaking process.

Meeting date and time	Location	Topic	Resources
Oct. 14, 2020	This meeting was held remotely via Zoom only.	Bacteria	Watch the recording of the meeting [VIDEO 39:33] Agenda White Paper - Bacteria DHS Standard Support Documents - Bacteria
Aug. 25, 2020	This meeting was held remotely via Zoom only.	Pesticides	Watch the recording of the meeting [VIDEO 01:42:26] Agenda White Paper - Pesticides DHS Standard Support Documents - Pesticides DATCP Pesticide Fact Sheets DNR Presentation DATCP Presentation DHS Presentation
July 21, 2020	This meeting was held remotely via Zoom only.	VOCs	Watch the recording of the meeting [VIDEO 01:08:31] Agenda White Paper - VOCs DHS Standard Support Documents - VOCs DNR Presentation DHS Presentation
June 9, 2020	This meeting was held remotely via Zoom only.	Metals and metalloids	Watch the recording of the meeting [VIDEO 01:24:36] Agenda White Paper - metals and metalloids DNR Presentation DHS Presentation DHS Standard Support Documents - Metals and Metalloids
March 23, 2020	This meeting was held remotely via Zoom only, following Governor Evers' order limiting the size of gatherings due to the risk of COVID-19	PFAS rules	Watch the recording of the meeting [VIDEO 01:45:29] Agenda Scientific support document for PFOA groundwater standard Scientific support document for PFOS groundwater standard Presentation: Evaluation of PFOA and PFOS for standards Presentation: Bioaccumulation factors for surface water standards Presentation: Updates and next steps for NR 140 and NR 809 rule changes
Feb. 6, 2020	Madison State Natural Resources Building (GEF 2) Room G09 101 S Webster St	PFAS rules	Watch the recording of the meeting [VIDEO 01:33:24] Agenda Presentation

Rulemaking procedures

Rule change process, public input and timeline

The DNR creates and revises administrative rules to implement statutes enacted by the Wisconsin State Legislature [exit DNR]. Administrative rules have the full force and effect of the law.

There is an extensive rulemaking process that the DNR and the Natural Resources Board must follow during a rulemaking effort. Public participation is a critical component of agency rulemaking with numerous opportunities to participate in the process. For permanent rules, the entire process generally takes about 31 months from initiation to effective date of rule revisions.