Impaired Waters: Delisting decisions

MPCA’s goal is to improve the water quality in the bodies of water on the Impaired Waters List. Bodies of water can be “delisted” from the Impaired Waters List if water quality improves. Delisting refers only to the situation for which new and reliable data or information indicates that the body of water is no longer impaired. In general, waterbodies will be assessed for delisting, using the same standards, guidelines, and thresholds that were used to place them on the list.

Improvements could be due to actions taken to lessen pollution from non-regulated sources such as agriculture and urban runoff, changes in wastewater treatment, or something else. If the new data show the waterbody to be unimpaired, either because the original, often smaller, data set provided a false indication of impairment, or because conditions have improved, the MPCA will petition the EPA to delist it.

Delisted water bodies are shown on a dedicated tab in the 2018 Impaired Waters List and can be identified using the online Impaired Waters Viewer.