WASHINGTON --The U.S. Environmental Protection Agency and U.S. Department of Agriculture should jointly establish a Nutrient Control Implementation Initiative (NCII) to learn more about the effectiveness of actions meant to improve water quality throughout the Mississippi River basin and into the northern Gulf of Mexico, says a new report from the National Research Council. The report also advises how to move forward on the larger process of allocating nutrient loading caps -- which entails delegating responsibilities for reducing nutrient pollutants such as nitrogen and phosphorus -- across the basin. In addition, the two agencies should jointly establish a Mississippi River Basin Water Quality Center to administer the NCII and to conduct related water-quality monitoring and research.
"A Nutrient Control Implementation Initiative would represent an important step toward EPA developing water-quality criteria and states setting water-quality standards," said David Moreau, chair of the committee that wrote the report and professor in the departments of city and regional planning and environmental sciences and engineering at the University of North Carolina, Chapel Hill. "However, efforts to reduce nutrients in the northern Gulf of Mexico will face significant management, economic, and public policy challenges, as well as a time lag -- a decade at minimum -- between reducing pollutants across the river basin and identifying water-quality improvements downstream in the gulf."
The Gulf of Mexico's oxygen-depleted "dead zone" derives from excess nutrients, such as nitrogen and phosphorus from fertilizers and other sources, flowing into the gulf from the Mississippi and Atchafalaya rivers. Numerous federal and state regulatory agencies and water-quality standards govern conditions across the 31-state river basin. To better meet nutrient and sediment reduction objectives in the Clean Water Act -- and in turn help improve water quality in the Mississippi River basin and into the northern Gulf of Mexico -- EPA asked the Research Council for advice on how to initiate nutrient pollutant control programs, identify alternatives for allocating reductions of nutrient discharges into bodies of water, and document the effectiveness of these strategies.
The committee recommended that EPA and USDA create the NCII to implement a network of pollution-control pilot projects to evaluate local and downstream water-quality improvements, and to compare results and enhance the outcomes of best management practices. The NCII should start with approximately 40 projects, which would be targeted to priority watersheds with high levels of nutrient pollutants. The NCII would represent a systematic approach to better understanding and managing nutrient inputs across the basin, and provide opportunities to strengthen interagency, interstate, and state and local coordination and cooperation. The committee noted that the collective reduction of discharged pollutants from the NCII projects would have little effect on the gulf's dead zone because the projects would cover only a small portion of the sources in the river basin. Therefore, other nutrient control actions and programs across the river basin should not pause or slow their progress to wait for NCII project development and implementation.
To gather additional data regarding the relative nutrient contributions of "point sources" -- such as water treatment plants and industries that have permits to release nutrients -- EPA should require major point sources to monitor the nutrient concentrations of their discharges as a condition of their permits. Although the estimated current flux of nitrogen and phosphorus being delivered to the Gulf of Mexico from these point sources is roughly 10 percent of the total, the relative importance and actual percentages are still debated. Requiring monitoring and reporting as conditions for discharge permits could substantially reduce uncertainties in the estimates of point source nutrient discharges, the committee said.
The report also recommends how EPA, USDA, and Mississippi River basin states should allocate nutrient loading caps for the river basin, including selecting an interim goal for the amount of nutrients that can enter the basin; identifying priority watersheds for nutrient control actions; adopting an allocation formula for distributing interim reductions; allowing credit for past progress; and encouraging the use of market-based approaches to allow jurisdictional flexibility. In moving forward on this front, all parties should look to the experience gained in setting nutrient loading caps in the Chesapeake Bay watershed, as it provides an example of how these processes have been developed in a large, multistate watershed with some similar water quality challenges. Information gained from the NCII would also be an important part of the process for determining loading reduction caps.
In addition, the committee proposed that EPA and USDA establish and jointly administer a Mississippi River Basin Water Quality Center to implement the NCII and conduct related monitoring and research activities. The center should manage a basinwide water-quality monitoring, assessment, and nutrient-control program and be located in the upper basin, where most nutrients enter the river system. Participation from other organizations that play important roles in water-quality monitoring -- such as the U.S. Geological Survey, the U.S. Army Corps of Engineers, and state natural resources and water-quality agencies -- would be vital. Some of the center's responsibilities should include coordinating NCII projects; conducting basinwide water-quality and land-use monitoring and relevant analysis and research; developing a land use and cover database for the basin; identifying additional watersheds for future NCII projects; providing advice on water-quality variables and statistical approaches; and producing periodic reports on basinwide water-quality assessments and project implementations.
Lastly, the committee stressed that the new water quality center, EPA, USGS, National Oceanic and Atmospheric Administration, and basin states should strengthen their commitment to systematic water-quality monitoring for the northern Gulf of Mexico in order to complement data gathered upstream and document the effectiveness of upstream nutrient-control actions.
|Contact: Jennifer Walsh|
National Academy of Sciences