EPA: Nutrient runoff is widespread waterway stressor

Four of every 10 miles of U.S. rivers and streams are in poor condition because of nitrogen and phosphorus runoff, said the EPA in its latest National Rivers and Streams Assessment. “The NRSA found that the percentage of river and stream miles in poor biological condition could be reduced by 20% if excess nutrient levels could be reduced from poor to good or fair,” said the report.

“Nationally, 28% of river and stream miles were in good biological condition while almost half were in poor condition,” said the EPA. Excess nitrogen levels was found in 44%, excess phosphorus in 42%, and excess riparian vegetation cover in 27% of river and stream miles. The report, based on a 2019-20 survey of stream conditions, was released in late December to little notice. Only 35% of stream miles had healthy fish communities.

Nutrient runoff is “a difficult problem that is concentrated in agricultural regions that drain into the Mississippi River,” said The Associated Press. The Midwest director of the Environmental Working Group told the AP that new water quality regulations were needed, rather than voluntary efforts.

The National River and Streams Assessment 2018-19 is available here.