2020-2021 triennial standards review

The 2020 – 2021 triennial standards review (TSR) is now complete. The comments received from the public for the TSR are available below, along with the MPCA’s response to the comments. The public’s comments informed development of the final water quality standards (WQS) work plan for 2021 to 2023, which will guide the agency’s WQS development work until the next TSR.

What is the triennial standards review?

The TSR is an opportunity for the public to provide input on the need for changes to Minnesota’s water quality standards — either new standards or revisions to existing standards. The federal Clean Water Act (CWA) requires that states review their WQS every three years and amend and update them if necessary. (Note: Rulemaking to implement revisions to state WQS is conducted separately from the TSR.)  

All parts of Minnesota Rules chapters 7050 and 7052 are open for the public’s review and comment.

Chapter 7050 includes provisions to protect Minnesota's waters from pollution, including:

  • A classification system of designated beneficial uses for both surface water and groundwater (e.g., drinking water, aquatic life and recreation, etc.), and a listing of specifically classified water bodies.
  • Numeric and narrative WQS that protect these beneficial uses.
  • Antidegradation provisions.
  • Provisions for the protection of wetlands.
  • Methods for the determination of site-specific criteria for toxic pollutants.
  • Other provisions related to the protection of surface water and groundwater from point and nonpoint source pollution.

Chapter 7052 provides standards specific to surface waters in the Lake Superior Basin. Chapter 7052 establishes aquatic life, human health, and wildlife WQS and criteria based on the EPA’s Great Lakes Initiative, anti-degradation standards and procedures for deriving effluent limitations from these standards and criteria.

Minn. R. chs. 7050 and 7052 also include procedures and requirements for issuing variances to state WQS. During the TSR the public may comment upon active variances that have been granted by the MPCA.

The public comment period for the 2020-2021 TSR began on January 19, 2021 and ended on April 9, 2021. One virtual public meeting was held on March 9, 2021 to answer questions and take comments from the public in a live format.  The materials and information provided to assist the public in its review are available in the sidebar links. They include the MPCA’s proposed water quality standards work plan for 2021 to 2023, which provided the public with the MPCA’s thoughts regarding priorities for WQS development to facilitate the public’s comments. 

The presentation slides and a video from the March 9 public meeting are posted below.

Public comments received

During the public comment period, MPCA received 659 written comments. Almost 90% (590) were form letters or a slightly modified version of a form letter prepared by the Minnesota Center for Environmental Advocacy (MCEA); several water quality standards (WQS) topics were covered in this letter.  Another 44 comment letters were a form letter or a slightly modified version of a form letter prepared by the Sierra Club that requested development of WQS for two pesticides: imidiproclid and clothianidin. The remaining 25 comments letters were submitted by environmental advocacy organizations, tribes, businesses, watershed districts, U.S. Environmental Protection Agency (EPA) and others, and cover a wide range of topics.

Comment letters are in three files, due to size. Each file includes an index. Form letters and a selection of comment letters that are slightly modified versions of the form letters are included. The other comment letters are included in full.  

Public meeting complete

The MPCA held a virtual public meeting to provide information on the TSR and accept comments on March 9. 2021.


  • Scope of the TSR or technical comments or questions: William Cole, 651-757-2788, 800-657-3864
  • TSR process: Catherine O'Dell, 651-757-2621, 800-657-3864