Amendments to Water Quality Standards: Use classification 2, ammonia

The MPCA plans to amend Minnesota Rules chapter 7050, which establishes beneficial uses and water quality standards (WQS) to protect those uses, and designates where the uses occur in waters of the state. The planned amendments affect the Class 2 beneficial use, which protects surface waters for aquatic life. This rulemaking proposes to revise an existing ammonia water quality standard to bring the protections of aquatic life up to date with current science.

Background

This rulemaking focuses on Class 2 (surface) waters protected for aquatic life, and one pollutant: ammonia. This rulemaking proposes to revise an existing ammonia water quality standard to bring the protections of aquatic life up to date with current science. The expected rule revisions include:

  •  An updated standard for ammonia to include EPA criteria — a final acute value, maximum standard, and final chronic value in Minn. R. 7050.
  •  Possible additions or revisions to Minn. R. 7053 necessary to support implementation.

Rulemaking documents

July 2022

Schedule

This is a tentative schedule.

Date(s)

Details

Aug. 1, 2022

Publish notice of request for comments and comment period in State Register

Summer 2022

Informal public engagement

To be determined

Publish notice of hearing on proposed rule amendments in State Register

To be determined

Public information meeting on proposed rule amendments
Public hearing on proposed rule amendments

To be determined

Final adoption of rules

Contact

  • Technical questions about planned changes to the ammonia standard: Robert Dietz, 651-757-2668

  • Questions about rulemaking process or schedule: Claudia Hochstein, 651-757-2622