Amendments to Water Quality Standards: Use classifications 3 and 4

The Minnesota Pollution Control Agency (MPCA) has adopted amendments to rules governing water quality standards for industrial consumption (Class 3), agricultural use (Class 4A), and livestock and wildlife use (Class 4B). The rule amendments are effective July 13, 2021.

These amendments establish narrative water quality standards with an accompanying “translation” step to determine whether permitted facilities require limits on the level of pollutants in their discharge in order to make sure that they do not cause or contribute to the kind of poor water quality these standards are designed to prevent.

These narrative translators are available on the Incorporations by Reference page.

Rulemaking schedule and process

Over the past few years, MPCA has gathered input and feedback on the proposed amendments to class 3 and 4 standards. The amended standards are the result of months of engagement and input from community partners across the state. MPCA received thousands of comments expressing concerns about the impact of amended standards on agriculture, industry and wildlife.

Late October 2020

To give the public more time to review the proposed rule language, the MPCA will post its draft rule on the agency’s website by October 30. The agency will not be soliciting comments on the draft until the formal notice period. The MPCA previously asked for public feedback during two comment periods in 2016 and 2019.

December 2020

The proposed rule language, along with Statement of Need and Reasonableness (SONAR), were published with a notice of intent to adopt the rule. The notice included a schedule for an administrative law judge hearing. The public may provide comments prior to the hearing through the rulemaking e-comments site at the Office of Administrative Hearings.

February 4, 2021

The Office of Administrative Hearings conducted an administrative law judge hearing. See resources posted in the Rulemaking and technical support documents section.

The public has an opportunity to provide comments during the post-hearing comment period that runs through 4:30 p.m. on Feb. 24, 2021.

Other points

March – August 2021

The Office of Administrative Hearings (OAH) report regarding the proposed rule changes is due 30 days after the close of the post-hearing comment period; it will be posted on the OAH web site. The report may lead to needed changes to the rule. If the rule is approved, MPCA will go through the process to formally adopt the rule and submit it to U.S. EPA for approval.

Rulemaking and technical support documents

July 2021

April 9, 2021

April 1, 2021

March 3, 2021

Feb. 24, 2021

Feb. 17, 2021

Feb. 4, 2021

PDF icon Public hearing transcript (Feb. 4. 2021) (wq-rule4-17q)

This is the official hearing record from the Feb. 4, 2021, public hearing.

Recording of the public hearing (6 hours)

Dec. 28, 2020

Dec. 14, 2020

Submit written comments to the administrative law judge via the Office of Administrative Hearings Rulemaking eComments website.

2020 Preliminary draft rule language

Comments will not be taken until the rule language and SONAR are made available as part of a formal Notice of Intent to Adopt Rules with a Hearing.

2019 Request for comments (March 11 - April 22, 2019)

2016 Request for comments (Feb. 8 – April 8, 2016)

2010 Evaluation from the University of Minnesota’s Department of Bioproducts and Biosystems Engineering

Contact information

For technical questions about these use classifications and the proposed changes:
Scott Kyser:, 651-757-2665