Impaired Waters List: 511 Added, 13 Removed 26 Sep 12

The Minnesota Pollution Control Agency (MPCA) has prepared the draft 2012 impaired waters list and is sending it to the United States Environmental Protection Agency (EPA) for approval. The list, updated every two years, includes 3,643 total impaired waters, 511 of which are new. The MPCA is also recommending that 13 formerly-impaired waters be taken off the list, or delisted, because they now meet water quality standards and are considered healthy.

Monitoring the state’s waters and determining their health is an involved process. The MPCA or its partners gather at least two years of monitoring data, and then analyze that data to determine if the waters meet state standards for important activities such as swimming, boating and fishing. If they do not, the waters are listed as impaired and undergo further study to determine how they can be restored to a healthy condition.

Restoring a water body so it can be removed from the impaired waters list can take many years, depending on the level of impairment and the management practices needed to fix the water quality problem(s). In 2010, the MPCA delisted seven water bodies; this year, that number increased to 13. According MPCA Director of Environmental Outcomes Shannon Lotthammer, “It is promising to see the number of restored waters nearly double since 2010. Staff, local partners and citizens put a lot of effort into restoring these waters – it’s great to see their efforts paying off.”

Delisting highlights include:

Jewitts Creek in Meeker County is the receiving water body for the Litchfield wastewater treatment plant. It was originally listed as impaired for ammonia in 1994. Excess ammonia can be toxic to certain aquatic animals. Because of upgrades to the wastewater treatment facility the ammonia problem was fixed.

Credit River in Scott County was impaired for water clarity. Citizens, Scott County, the city of Savage, MPCA and other partners worked to clear up the river by installing rain gardens to filter urban runoff and stabilizing eroding slopes with vegetation.

During the public comment period this past spring, there were requests for delisting the Mississippi River’s Pool 2. Pool 2 was listed as impaired for perfluorooctane sulfonate (PFOS), a synthetic chemical belonging to the perfluorinated chemicals (PFC) family. Although the MPCA feels that progress has been made, and recent data on Pool 2 are promising, additional data are needed to be confident that the problem has been addressed and the impairment can be delisted. The MPCA is in the process of collecting data to allow further evaluation of this impairment.

The MPCA has initiated or completed water monitoring in 52 percent of the state’s 81 major watersheds. The state is on track to monitor all of the state’s watersheds on a 10-year schedule. For more information on the proposed 2012 Impaired Waters list and methodology for listing, visit the MPCA’s website at