New Study Pinpoints Nitrogen Pollution Sources and Solutions

4/15/2003

From: Sharon Pickett, 301-365-9307 Kelly Rodoski, 315-443-5381 both for the Hubbard Brook Research Foundation

WASHINGTON, April 15 -- Nitrogen pollution is harming forests, streams and coastal waters but can be alleviated, reports a team of 12 leading scientists in a study released today in a special issue of the journal BioScience. The authors of the study pinpoint air pollution and wastewater effluent as the leading causes of nitrogen pollution to forests and estuaries of the Northeastern U.S.

The report provides a scientific basis for evaluating clean air proposals currently before Congress including a new bill introduced by Senator Judd Gregg (R-NH) earlier this month and two bills introduced by Senators James Jeffords (I-VT) and James Inhofe (R-OK) in February of this year. "In clear and decisive terms, this report confirms the need for cuts in nitrogen oxides similar to those outlined in my multi-pollutant bill if we want to see healthier people and ecosystems in the next 50 years," said Senator Jeffords), ranking member of the U.S. Senate Environment and Public Works Committee."

The study synthesizes data on the effects of nitrogen pollution and evaluates possible solutions. Impacts on forests and watersheds cited by the authors include diminished forest productivity (up to 14 percent in some areas) due to nitrogen-induced ozone, and nitrogen-driven pulses of acidity that impact approximately 41% of lakes in the Adirondack region of New York and 15 percent in New England.

"In all the watersheds we examined, airborne emissions of nitrogen and nitrogen discharged from wastewater treatment plants were the overwhelming sources of nitrogen pollution to forests and coastal waters in the Northeast," said co-author Dr. David Whitall of the Hubbard Brook Research Foundation, the group that organized the new study.

The authors report that the current Clean Air Act (as amended in 1990) will not reduce nitrogen emissions enough to prevent damage to northeast forests and reverse acid rain impacts to lakes and streams. The analysis shows that additional reductions in total nitrogen emissions of 30 percent or more would be needed to reduce nitrogen runoff to less harmful levels.

"Despite the reductions in sulfur emissions that have been achieved by the 1990 Clean Air Act, little progress has been made in reducing total emissions of nitrogen. So unfortunately, we weren't surprised that airborne nitrogen pollution continues to be a serious problem for Northeast forests and streams," noted lead author Dr. Charles Driscoll, University Professor and Chair of the Department of Civil and Environmental Engineering at Syracuse University.

The study also assesses nitrogen pollution in estuaries -- the ultimate receiving waters for much of the nitrogen produced in the regions watersheds. The authors confirm that excess nitrogen can lead to over-enrichment of coastal waters that has been shown to deplete oxygen levels and degrade critical sea grass habitat.

The study demonstrates that upgrades to wastewater treatment plants using currently available technology could reduce nitrogen loading to coastal waters, such as Long Island Sound, by as much as 57 percent -- a level that would improve the low oxygen conditions experienced in the Sound annually.

"By quantifying all the sources of nitrogen in the watersheds that drain to 8 estuaries in the Northeast, we were able to predict the effects of specific policy options. And the result was clear, improved wastewater treatment is the single most effective means of reducing nitrogen pollution in coastal waters of the Northeast," concluded Dr. Mark Castro, Associate Professor at the University of Maryland.

This study adds to the growing body of evidence concerning the severity of nitrogen pollution nationwide and the need for policy reform to address the problem. Four additional papers in this special issue of BioScience highlight: the power of nitrogen to create a "nitrogen cascade" (Galloway et al.), the fact that airborne nitrogen pollution has altered Northeast forests (Aber et al.), and the impacts of airborne nitrogen pollution in the Western U.S. (Fenn et al.).

Despite the pressing nature of nitrogen pollution, initiatives to address the problem appear to have stalled or been rolled back. The Bush Administration recently weakened the Clean Air Act provision that required electric utilities that expand to improve emissions controls (known as New Source Review) -- causing the Attorneys General of nine Northeast states to sue the federal government. On the water front, the U.S. EPA released a study last year that has gone largely unanswered, highlighting the $30 billion gap in clean water financing needed to address nitrogen and other water quality issues.

"Solving the nitrogen problem nationally will require a multi-pronged approach. We now know that in the Northeast, two of these approaches must be reduced air emissions and improved wastewater treatment," said Kathy Fallon Lambert, executive director of the Hubbard Brook Research Foundation.

The paper "Nitrogen Pollution in the Northeastern United States: Sources, Effects and Management Options" can be downloaded from the BioScience website at http://www.aibs.org/bioscienceonline/

A summary of the BioScience article and lay report for the general public can be found at http://www.hubbardbrook.org/hbrf/nitrogen

The Hubbard Brook Research Foundation is a non-profit organization established in 1993 to provide support for the Hubbard Brook Ecosystem Study and develop new initiatives linking ecosystem science and public policy. The HBRF Science Links program was created to increase the exchange of information among scientists, land managers, and policy-makers. It focuses on identifying important policy issues that can benefit from increased access to scientific research.