A survey of U.S. rivers and streams found more than half have poor living conditions for aquatic species. Streams in the Midwest, including Minnesota, had major problems with phosphorus and nitrogen.
The Environmental Protection Agency studied more than a million miles of U.S. waterways and found that over half had poor living conditions for aquatic species.
Denise Keehner, the EPA's director of the office of wetlands, oceans and watersheds, said her agency is talking with states to find ways to reduce the pollution.
"Doing the work to define what types of things need to be done," Keehner said. "What's the most cost effective, what's the most expedient way of taking action right now based on the information that people do have to try to mitigate or reduce nitrogen and phosphorus loadings into our waters."
In the region which includes western Minnesota, about 58 percent of the rivers had high levels of nitrogen.
Keehner said high sediment levels are also a problem. Much of that is linked to farmland runoff.