Expert Report

Each report is produced by a committee of experts selected by the Academy to address a particular statement of task and is subject to a rigorous, independent peer review; while the reports represent views of the committee, they also are endorsed by the Academy. Learn more on our expert consensus reports.

This report offers advice and priorities to the U.S. Environmental Protection Agency on improving water quality in the Mississippi River basin and Northern Gulf of Mexico—including how to better manage and monitor nutrients, especially nitrogen and phosphorus.

Most nutrient pollution across the river basin comes from diffuse, hard-to-trace sources known as nonpoint sources—for example, the majority of nitrogen and phosphorus loadings come from agricultural landscapes and activities. Reaffirming a recommendation from a 2008 National Research Council report on Mississippi River water quality, this report proposes that the Environmental Protection Agency establish a numeric limit for the amount of nutrients in the waters of the northern Gulf. These "nutrient criteria" would provide an endpoint that the Environmental Protection Agency and the Mississippi River states can use to begin working upstream in setting water quality standards for nutrients and processes for improving water quality.

In addition the Environmental Protection Agency, Congress, the Administration, federal agencies, and states should collaborate better and provide stronger leadership, the report says. It recommends that the Environmental Protection Agency, its partner federal agencies, and Mississippi River basin states develop a more action-oriented, basinwide strategy to address nutrient-related water quality problems throughout the basin than has been used to date.

Key Messages

  • A basin wide action plan—developed by the Environmental Protection Agency, its partner federal agencies, and the Mississippi River States—would address nutrient-related water quality problems throughout the Mississippi River Basin and the Northern Gulf of Mexico. There have been some federal and state efforts to coordinate nutrient management and related water quality programs across the Mississippi River basin. To date, however, these interagency efforts have not produced a rigorous, action-oriented plan that includes clear performance measures, milestones, and deadlines, for reducing nutrient loadings.
  • A stronger and more coordinated commitment from the Environmental Protection Agency, its partner federal agencies, the Congress, the Administration, and the Mississippi River Basin States is needed to help develop long-term, adaptive and collaborative actions for effectively addressing water quality problems across the Mississippi River Basin and into the Northern Gulf of Mexico.
  • Establishing establish a numeric limit for the amount of nutrients in the waters of the northern Gulf would act as an endpoint for the Environmental Protection Agency and the Mississippi River States to set water quality standards for nutrients throughout the basin.
  • Support and advice from the Environmental Protection Agency could strengthen the activities of the Department of Agriculture Mississippi River Basin Healthy Watersheds Initiative. The Initiative is a four-year, $320 million program designed to promote improvements in water quality at 41 watersheds across the Mississippi River basin.