Minnesota’s Impaired Waters List

Every two years, MPCA creates a list of impaired waters that do not meet water quality standards. Monitoring suggests that about 40% of Minnesota's lakes and streams are impaired for conventional pollutants. Learn more: Defining impaired waters.

2018 Impaired Waters List

2018 Impaired Waters List

Minnesota’s 2018 Impaired Waters List was approved by the U.S. EPA on January 28, 2019.

File 2018 Impaired Waters List (wq-iw1-58)
  • 2018 TMDL (303(d)) List
  • 2018 Inventory of All Impaired Waters
  • Appendix A of the Statewide Mercury TMDL (Impairments added to the TMDL)

PDF icon 2018 Guidance Manual for Assessing the Quality of Minnesota Surface Waters for Determination of Impairment 305(b) Report and 303(d) List (wq-iw1-04j)

Describes Minnesota's monitoring and assessment strategy, assessment tools, and the redesigned assessment process. The purpose of this guidance is to define the required data and information and lay out the criteria by which waterbodies are assessed to determine if beneficial uses are supported.

PDF icon US EPA’s decision document on Minnesota's 2016 and 2018 Impaired Waters Lists (wq-iw1-63)

The MPCA has not finalized methods for identifying waters used for production of wild rice or for assessing impairment of waters based on the existing wild rice-related standard. Consequently, the 2018 303(d) Impaired Waters List does not include any waters assessed as impaired for the sulfate wild rice standard. The MPCA continues to consider next steps for the sulfate standard to protect wild rice.

Public comment

The 2018 list was open for public comment (Nov. 27, 2017, through Jan. 26, 2018).

PDF icon Compilation of all public comments received on the 2018 Draft Impaired Waters List (wq-iw1-58a)

PDF icon Responses to all public comments received on the 2018 Draft Impaired Waters List (wq-iw1-59e)

Other information

PDF icon 2018 Minnesota Water Quality - Narrative report to Congress (wq-s7-51)

Also known as the 305(b) Integrated Report, combines two requirements of the Clean Water Act to report to Congress on the quality of Minnesota's waters.

For GIS professionals: Go to MPCA's spatial data webpage to download shapefiles on Minnesota's impaired waters.



Have questions or need assistance? Contact Miranda Nichols, 651-757-2614 or 800-657-3864 toll free.