A good guess. Scientists studying how to clean up the Neuse River say that’s what they have after logging soil samples, dissolved oxygen readings, and satellite maps. They already know that slow-flowing waters and a heavy dose of nutrients provide some of the best waters around for growing algae. Algal blooms were linked to the headline-grabbing fish kills of 1995. Blooms fostered the predatory “cell from hell,” Pfiesteria piscicida. In response, the General Assembly agreed on a number in 1997: reduce nitrogen runoff by 30 percent. 

A round table of scientists in Raleigh came up with that figure, says David Moreau, professor and chair of the city and regional planning department. But the real policy victory will come when people living in the river basin, from Orange County to Cedar Island on the coast, change their ways. 

The Environmental Management Commission says we want that thirty percent reduction in five years,” says Moreau, the group’s chair. “It’ll take more than the commission saying that for it to actually happen. To start with, do you think anyone in the farm community has lost any sleep over that number?” 

Not to single farmers out, but Moreau and state water-quality experts believe that agriculture is responsible for as much as 60 percent of the nitrogen flowing into the Neuse River. Another 25 percent of the nitrogen comes from the 27 permitted sewage plants and industries along the river. Farmers and city residents together share the cost of cleaning up what flows downhill. 

If the river basin were a drain rack resting in a giant sink, then every dish and piece of silverware would represent a building, farm, road, or car. When it rains, nutrients and pollutants wash off the rack, into the sink, and into the river. Gravity: it’s the law. 

Scientists like Moreau work on much more advanced models than a drain rack, accounting for small-scale polluters as well as larger ones. So small, he says, golf course owners spreading fertilizer on greens or farmers spraying manure slurry on crops will understand their role. 

The scale must be so small that we understand how an individual farm operation affects the ecosystem,” he says. “We also have to measure how these policies influence people’s behavior. How does that policy get transmitted to these people, how many of them understand it, and how many of them respond in the way that the policy assumes they're going to respond?” 

Ken Galluppi is one of the scientists building such a model. He works with the Carolina Environmental Program (CEP), which was created by the provost’s office to coordinate cross-disciplinary research on the environment. Galluppi coordinates a team of scientists from the Environmental Protection Agency (EPA), the state Department of Environment and Natural Resources (DEHNR), UNC-CH, and N.C. State University. Galluppi calls the project a community model. He quickly explains the difference between this model and a drain rack. 

We want to know how pollutants are being transferred, in this case nitrogen and carbon, into the river,” he says. “But we also want to be able to measure the true response to the ecosystem. To do that you have to put people into the system.” 

For example, citizens complain to the state after a massive hog-lagoon spill kills thousands of fish. The state levies a fine. But does the fine encourage the farmer to change the way he disposes of hog manure? 

If he says, `I can live with a fine,’ and goes about his business, then the environment hasn’t really changed,” Galluppi says. 

Models aren’t new to science. Firstgeneration models simply ad-dressed, for example, the chemical inputs and outputs of a tree. Galluppi took the idea a step further while working for the EPA, applying a modeling approach to acid rain in the 1980s. “Is it really acid rain that’s killing these trees? If so, how does it work?” he asked. The second generation of models, he says, was applied to real problems. 

In 1990, Galluppi wrote a “white paper” on modeling for the EPA. He outlined a need for models that would show how a host of pollutants interact. By 1991, the EPA was requiring states to adhere to specific air pollution models under the Clean Air Act. Regulators set about trying to figure out how something as nebulous as air pollution really worked. 

At a workshop on air quality in spring 1997, a friend of Galluppi's, Robin Dennis from the EPA, sat down at a table with two Carolina professors, Harvey Jeffries and Hans Pearl. Jeffries studies air quality. Pearl works at the Institute of Marine Sciences monitoring estuary ecosystems. The conversation turned to the Neuse River. 

They realized, hey, this is really complicated,” Galluppi remembers. “What’s causing the nitrogen loading? Is it airborne nitrogen or simply runoff systems? Later, we kicked around the idea of doing a conceptual model of the entire Neuse River to understand the whole system.” 

When William Glaze, director of the CEP, asked Galluppi to create a community model at Carolina, Galluppi jumped at the idea. 

Since then, scientists have met to determine what the model should look like. Galluppi says at first it was like the tale of the blind men who touch different parts of an elephant. Each researcher addressed a different part of the same problem. “Various groups will work on pieces of the model they have experience with,” he says. 

Some parts of the elephant-sized model aren’t so rough. Harvey Jeffries, professor of environmental sciences and engineering, says that weather modeling will help predict air pollution patterns. “These meteorological models are used to cover storms,” he says. “The problem we're having is that air pollution is often a low-atmospheric energy event. During an ozone alert, there are no frontal passages. The air is pretty still.” 

To predict air pollution, scientists start with weather data on wind speed, air temperature, and moisture. Jeffries says once they have the weather model in place, they can figure in other variables, such as vehicle emissions. A mobile-sources model records how many vehicles are on the road at any one time, sorted by type: trucks, cars, even motorcycles. Depending on the vehicles’ speed and mileage, the model can tell how much air pollution they produce. 

Still, linking policy to people’s everyday practice may be the most diffi-cult part of a community model. 

We have a pretty good understanding of the behavior of municipalities and industries,” Moreau says. All of the significant dischargers will comply because they have a permit holding them accountable for the amount of nitrogen they discharge. “But what was it that formed the public’s mind about the river and the people who are imposing stress on the river?” 

Was it The News & Observer’s “Boss Hog” series? Television and newspaper coverage of a huge hog-manure spill, or the sight of all those fish belly up on the river? 

I think this whole process here is very poorly understood,” Moreau says. “It’s a complex web, and I’m not sure how you do the case studies that would shed considerable light on that. That would be an interesting piece of research on public attitudes.” 

Galluppi says the community model will include the public. He plans to invite industries like Weyerhaeuser, one of the largest landowners along the Neuse River, as well as environmental groups like the Neuse River Foundation to talk about the river. 

We need to show nonscientists the economic costs of our clean-up decisions,” he says. “It’s more than just a certain amount of dollars for fertilizer that gets passed along to the consumer. Maybe we can’t predict the impact of that fertilizer, but we can get a sense of what’s going on.” 

When it comes to large environmental problems, he says, we should be able to break them down, figure out the actual costs, and come up with an answer that's good for everyone and the river. 

Christopher Hammond was a student who formerly contributed to Endeavors.

Community model research is funded by the N.C. Department of Environment and Natural Resources and the EPA's Office of Water.