GRASPING FOR SOLUTIONS - While many states are failing to protect rivers and watersheds from polluted runoff, some communities are taking matters into their own hands - diffuse pollution threatens American waterways

National Wildlife, April-May, 2001 by Joby Warrick

On bright days when the Clinch River in southwestern Virginia runs clear, you can see signs of rebirth strewn along its rocky bottom like so many black pearls. Braven Beaty, an aquatic ecologist in rubber waders, pokes an arm into the mountain stream's icy swirl and pulls out a hopeful omen.

"Black sandshell," he calls out, rotating a small mussel between fingertips. "A threatened species. I've never seen one this far north."

The scientist returns the mussel to its place and scoops up another, and then another, reciting the names of the species as he finds them: fine-rayed pigtoe; kidneyshell; rough rabbitsfoot. In half an hour, he finds 12 different species in a spot no bigger than a carport.

The variety is striking, even for a stream that boasts more varieties of freshwater mussels than any waterway on Earth. But equally striking are the absences: Once there were as many as 60 types of mussels in this Appalachian river before pollution and silt from a century of logging and coal mining wiped out a third of them-forever.

The Clinch's mussels are slowly coming back, but so far recovery is limited to areas protected by a fragile alliance of conservationists and property owners working to keep sediments out of the water. "It's hard to get people to understand why mussels are important," says Beaty. "It's even harder to go to landowners and say, 'You're part of the problem.'"

Drawing a connection between land and water is crucial, not only for the Clinch but also for hundreds of other waterways around the country. In an era when environmental regulations have stemmed the flow of pollutants from many U.S. factories, rivers are straining under a burden of chemicals and silt from thousands of smaller sources- everything from poorly managed logging projects and animal waste from factory farms to motor oil off parking lots and weed killers from suburban lawns.

Such diffuse, or nonpoint, pollution is now the Number One cause of contamination in American waterways, fouling an estimated 1.3 million miles of streams and rivers. It is the main reason nearly 40 percent of the nation's lakes, rivers and estuaries still are not clean enough for swimming or fishing, according to a 1997 Environmental Protection Agency (EPA) analysis.

"The magnitude of the problem just hasn't been recognized," says Michael Murray, an NWF environmental chemist and staff scientist, "and as a result we're seeing nonpoint pollution getting even worse in a lot of areas of the country." The situation, he adds, is compounded in many areas by air pollution, which contaminates waterways with dioxins and other chemicals emanating from distant sources.

An NWF study released last spring reported that states simply are not enforcing the law when it comes to preventing diffuse pollution from washing into streams (see sidebar). "The failure is inexcusable and the problems are preventable," concludes the report. "The tools for cleaning up polluted runoff and contaminated rain are there, but most states simply aren't using them aggressively enough."

For states, the primary legal weapon against nonpoint pollution is called the Total Maximum Daily Load (TMDL) restoration program. Created with the passage of the federal Clean Water Act in 1972, the TMDL provision requires regulators to consider all sources of pollution across a river's watershed, or drainage basin.

A watershed is the area of land from which rain or melting snow drains into a river. It can be as small as a few hundred acres-typical of a small stream-or it can encompass thousands of square miles and several states, as in the case of the Mississippi River. In all watersheds, the rainwater that replenishes the river also brings wastes that can damage it. Unless preventive steps are taken, pollutants can be swept up in storm runoff and deposited in the river itself.

A TMDL plan helps states identify these hidden problems. The program starts with careful monitoring of water quality by state regulators, along with an investigation of where the pollutants are coming from. Next, the states set limits for each type of pollution-the "total maximum daily load" a river can safely carry. When a river exceeds the limit for a chemical, the state crafts a pollution-reduction strategy that divides the cuts among both point and nonpoint sources of the chemical. States have discretion in determining how the actual allocations are made, with the only requirement that the reductions result in attainment of water-quality standards.

"This TMDL approach makes a clean-up effort more effective and fairer to all parties," says Murray. It can also yield surprising insights: In the Christina River Basin near Wilmington, Delaware, for example, officials discovered that farming and suburban sprawl had eclipsed the state's homegrown chemical industry as the leading source of the river's problems. Runoff from farms, lawns and parking lots alone destroyed or damaged fish habitats in nearly 40 percent of the river's tributaries, according to a TMDL investigation.