Working from his office in Cambridge University, Sir Isaac Newton in 1701 put on paper the mathematical equation that explained the law of gravity.

Three hundred years later, people are trying to figure out how to make that law apply to air pollution programs.

While it seems evident that much of the pollution spewed into the air will ultimately find its way back to the ground — and into the water — clean air laws primarily relate to “ambient” air quality, or the amount of pollutants in the air that people actually breathe.

But growing evidence suggests that air pollution contributes to water quality problems in the Chesapeake and other coastal waters. With that in mind, state and federal officials, along with representatives from environmental and industry groups, met at a recent workshop to determine how — and if — water concerns should play a role in air regulation.

“Air deposition is an important source of pollution to coastal water bodies,” Bill Matuszeski, director of the EPA’s Chesapeake Bay Program Office, told participants at the Airsheds and Watersheds workshop which took place in North Carolina in early March.

Just as water quality managers in the past sought pollution reductions from sewage treatment plants and agricultural runoff, Matuszeski said they must now seek reductions in air pollution to help clean up coastal water bodies.

“Is there something especially offensive about air scientists and regulators that we ought to walk away from them?” he asked. “Air regulators are less likely to have sewage sludge or manure on their feet. I don’t quite understand why we want to walk away from these folks. There is definitely an impact from what they are doing and the decisions they are making.”

It was the third of a series of “shared resources” meetings conducted in recent years to bring together water quality managers from estuaries along the East Coast to discuss issues of mutual concern. It was the second shared resources meeting to focus exclusively on air pollution issues.

The main concern was on nitrogen oxide emissions, which can contribute to eutrophication problems — the lack of oxygen — in estuaries and other coastal waters. Excessive amounts of nitrogen in salt water spurs algae blooms which ultimately die, sink to the bottom and decompose in a process that depletes the water of oxygen needed by fish and other aquatic animals.

About 27 percent of the nitrogen entering the Bay originates from air sources, along with 44 percent of the nitrogen to Albemarle-Pamlico Sounds in North Carolina, 15 percent in Delaware Bay, 20 percent in Long Island Sound. Other East Coast estuaries report varying amounts in that range.

But the issue isn’t clear cut. Not all the nitrogen entering those water bodies from the air results from air pollution. Some results from natural sources. And some nitrogen, in the form of ammonia, doesn’t stem from smokestacks or tailpipes, but volatilizes into the air from manure pits and fertilized fields.

Of the airborne nitrogen that ends up in the Bay, about 75 percent is estimated to result from nitrogen oxide (NOx) emissions from power plants, automobiles and other fossil fuel-burning sources.

But in other places, such as North Carolina, officials are less sure about contributions from various air sources. A larger portion of the airborne pollution reaching the water in that state appears to result from ammonia volatilizing off huge animal farms near the coast than is the case in the Chesapeake and elsewhere.

“We’re not fully comfortable yet that we know enough about the sources of these compounds — their routes of entering and passing through the environment, and their eventual fates — to properly allocate priorities to all the apparent contributors to the problem,” said Jonathan Howes, secretary of the North Carolina Department of Health and Natural Resources.

Others said that much of the air pollution from the Chesapeake north originates from NOx emissions — much of which comes from the Midwest — which can travel hundreds of miles.

Despite several decades of efforts to control pollution from power plants, industries and automobiles, nationwide NOx emissions are about 23 million tons a year according to the EPA. They increased about 14 percent between 1970 and 1995, in large part because of growth. For example, the total amount of NOx from automobiles today is about the same as 1970 because the number of miles traveled has doubled, according to the EPA.

Recent regulations aimed at reducing acid rain, and additional NOx reductions for automobiles required in the 1990 Clean Air Act Amendments, are expected to reduce nitrogen oxide emissions between now and 2006. But the EPA projects that NOx emissions would then pass current levels unless additional controls are enacted.

The workshop came at a critical time. Major air pollution decisions will be made in the coming months and years that could dramatically affect the amount of nitrogen that enters coastal waters.

“Policy is going to be made with us, or without us,” Bruce Hicks, of the National Oceanic and Atmospheric Administration’s Air Resources Laboratory, told workshop participants. “The question is, are we comfortable with that?”

Among actions under way or coming soon:

  • The EPA in March proposed new ambient air quality standards for ozone and fine particulates. Nitrogen oxides are a major contributor to both problems, and the stricter standards, if they become final in July, would require significant NOx reductions. If the new standards are adopted, plans for their implementation — outlining specific pollution control strategies — would be written over the next few years.
  • A group of 37 states have formed the Ozone Transport Assessment Group, which is trying to develop a pollution control strategy that would bring cities that chronically exceed the EPA’s ozone standard into compliance. The main issue the group is dealing with is NOx control, because it can drift hundreds of miles, contributing to ozone problems far downwind. The OTAG process is trying to find a way to control “upwind” pollution sources so downwind areas can meet the ozone standard. Its recommendations are expected by summer. The EPA is expected to require states to write “implementation plans” that incorporate some or all of OTAG’s recommendations.
  • The Ozone Transport Commission — a smaller version of OTAG, which tries to deal with ozone problems from Northern Virginia through Maine — has been requiring stricter NOx controls throughout the Northeast and is exploring additional actions.
  • Legislation to deregulate the electric utility industry could help or hurt NOx reduction efforts. If legislation does not take pollution from power plants into account, there is concern that power generation would increase electricity generation at old, underused plants in the Midwest, which generate more pollution than newer plants. In that case, they would add to pollution problems in eastern states. But if the legislation takes pollution into account, and sets firm “caps” for NOx emissions, it could result in lower emissions.

With those efforts going on — on top of acid rain controls and new automobile emission controls — some were skeptical that water issues would carry much weight in upcoming decisions.

“I think we have a fair amount in the pipeline, and a tremendous amount more staring us in the face regarding ozone and other issues,” said John Kinsman, of the Edison Electric Institute. “I would greatly encourage you to keep plugging away at other pieces of the puzzle. But if these other things don’t work [to achieve further air pollution reductions], I don’t think eutrophication is going to do the trick.”

Others argued that people concerned about water quality cannot assume air regulators will take their needs into account, and must be actively involved in crafting air pollution laws and regulations.

“You are not going to be able to leave the air regulatory programs alone,” said David Hawkins, senior attorney with the Natural Resources Defense Council. “The benefits that you think are coming anyway as a result of these programs may not come at all, or they may not come in the amounts needed to address all the environmental issues unless all the benefits of taking these regulatory actions are identified. I can assure you that all of the costs will be identified and trumpeted loudly.”

Hawkins noted, for example, that many of the NOx reductions are aimed at reducing summertime ozone levels — to which NOx is a major contributor. To help that problem, it is possible that NOx reductions could be implemented only in the summer months, minimizing benefits to water bodies which are impacted by airborne deposition year-round. Hawkins said some utilities had advocated having increased emissions during winter months in exchange for reduced summer emissions.

Keynote speaker Bob Perciasepe, EPA assistant administrator for water, said headway is being made in connecting air and water pollution issues. For example, he noted that an EPA acid rain regulation issued in December requiring a 900,000 ton a year reduction in NOx emissions from coal-fired power plants specifically stated that the Chesapeake Bay and other coastal waters would also benefit from the action.

“Part of that is a result of the work that you all have been doing,” Perciasepe said. “You have broadened the public debate as to what the benefits are to some of the air programs.”

And, he noted, when EPA Administrator Carol Browner unveiled proposed new ambient air standards for ozone and particulates last November, she touted the benefits of the action for water quality, as well as for human health. “I thought it was a significant moment, to me, that the administrator of EPA, in announcing this action … would get up and say in front of her main press conference that there are significant water benefits to that,” Perciasepe said.

But, he cautioned, “there are still many legal constraints to some of the things that we are talking about.” Because the Clean Air Act is primarily focused on public health issues, he said it is unclear the extent to which it could be used to protect water quality. “And there is little chance, I believe, of the Clean Water Act or the Clean Air Act being amended in the near future in a way that is positive in this arena,” Perciasepe said.

He challenged workshop participants to continue to refine their efforts to better link the pollutants that go into the air with those that enter water bodies, and to explore administrative “paths” that allow air and water regulatory actions to work together. “It’s not that people are dumb and don’t want to do it,” he said. “It’s that these paths are dead ends right now.”

Perciasepe said the importance of air pollution issues for water was likely to grow in the future, as research indicates that air is not only a major source of nutrients to water bodies, but also a significant source of toxics.

“Nutrients are perhaps easy compared to the toxics part of this,” he said. “ We are finding more and more that the toxics that we are finding in the water bodies are coming out of the air. Almost 100 percent of the mercury loadings [to water] in the Northeast and the Midwest are from the air.”

Fish in the United States have a “background level” of 1.8 parts per trillion of dioxin as the result of air pollution, he said, which translates to a 1 in 1 million cancer risk to people eating fish before anything else is even put in the water.

“This is an emerging air-water issue perhaps even more difficult, and of even more significance, than some of the nutrient ones,” he said.