Volunteers fished more than 22,000 pounds of trash, including 56 tires, two toilets and a boat trailer from the first 50 miles of the Upper Neuse River near Raleigh last month, but the greatest threat to the waterway is what no one sees.

Growth throughout the river basinfrom its headwaters near Falls Lake in Durham through sprawling Wake County, and southeast to the swanky developments along Pamlico Soundis threatening the river, landing the Neuse on this year’s Top 10 Most Endangered Rivers list.

The annual list is compiled by the American Rivers Foundation, a nonprofit conservation group based in Washington, D.C.

Like the Native Americans who lived along it 14,000 years ago, 21st-century settlers are attracted to the river’s resources: water, fish and the plants that grace its banks. Over the next 20 years, Wake County’s population is projected to explode like algae blooms to 1 million peoplea 70 percent increase since 2000. That means there will be more toilets to flush and more yards to irrigate, placing further demands on Falls Lake, a water source for 350,000 Wake County residents. More people means more dirt to be bulldozed and more pavement for nitrogen-laden fertilizers and pet waste to run over, into the river and its tributaries. Excess nitrogen kills aquatic life and jeopardizes commercial fishing near the coast.

“What is it going to take to get Raleigh and everybody else to recognize what an important resource Falls Lake and the Neuse River are to this region?” asks Dean Naujoks, Upper Neuse Riverkeeper.

Most of the Neuse River Basin lies south of Wake County, but local officials say they are aware of the strain additional people, water demand and wastewater discharges will place on the river here and downstream.

“Growth and wastewater go hand in hand,” says T.J. Lynch, superintendent of Raleigh’s wastewater treatment plant. “There’s research to be done whether the river can handle additional wastewater.”

It appears that the Neuse has no choice. The plant, a labyrinthine facility snaked with pipes and tanks and pumps, will likely expand over the next five years. It underwent $40 million in improvements after it was cited for violations related to its discharge; now the city plans to ask the N.C. Department of Environment and Natural Resources for a permit to increase the amount of treated wastewater discharged daily into the Neuse from 60 million gallons to 75 million gallons.

Although urban lawns are usually the culprit for pesticide and fertilizer runoff, the plant has encountered similar problems from its application fields. Treated biosolids, dried byproducts of the treated wastewater, are spread on fields that grow crops, such as corn and soybeans, for farm animals. (Crops fertilized with these biosolids aren’t approved for people to eat.)

Bill Showers, associate professor of marine, earth and atmospheric sciences at N.C. State University, has conducted an EPA-funded study of nitrogen levels in the Neuse. He discovered that extra nitrogen was coming not from treated wastewater, but from the public utility’s 1,000-acre application field that borders the river, which winds around plant property. While the amount of nitrogen entering the Neuse is still within permitted limits, Showers says, “it isn’t supposed to go outside the field boundaries and it’s going into the river.”

Showers speculates that deeply eroded streams are funneling water from the application fields into the river, especially during heavy rains. The next step is to design a wetlands system that will filter nitrogen from the water before it enters the river. “The challenge is to come up with a sustainable solution,” he says. “As the population grows, the wastewater treatment plant is going to get larger and there will be more pressure on the utilities to buy more fields.”

At a glance: Neuse River Basin

  • Total area: 6,235 sq. miles
  • No. of counties: 18
  • No. of municipalities: 74
  • Population (2000): 1,353,617
  • Freshwater stream miles: 3,497
  • Freshwater lakes acres: 16,414
  • Coastline miles: 21

Source: N.C. Dept. of Environment and Natural Resources

According to a December letter to Raleigh Public Utilities from the N.C. Department of Environment and Natural Resources, the city asked DENR for a variance, which would allow a to-be-determined amount of nitrogen to run off the fields, as long as the plant reduces an equal amount in its discharge. The Environmental Management Commission, a 19-member group appointed by the governor and House and Senate leadership, is scheduled to hear the case later this year.

It’s not only runoff from cornfields and hog farms that threatens the Neuse and its tributariesmany of which are on a federal impaired waters listbut also dirt washing from the hundreds of development sites in Wake County. As land is cleared and graded for new subdivisions, dirt runs into storm drains, streams and the Neuse; sediment is the river’s top pollutant.

Britt Stoddard, Wake’s watershed manager, says the county is trying to combat runoff by prohibiting development in the floodplain, increasing buffers between waterways and development sites. Moreover, Wake County officials aim to preserve 30 percent of the county’s land; 10 percent is already preserved through N.C. State and Umstead Park.

Wake County Planning Director Melanie Wilson says there are watershed development standards, but many of the subdivisions in those sensitive areas were grandfatheredapproved before the regulations were established.

“When I do the numbers [of projected population growth], I worry,” Wilson says. “But we’re being more proactive and aggressive to address development and stormwater management.”

Raleigh Planning Commissioner Betsy Kane says while erosion ordinances help curb runoff, those regulations don’t apply to all sites. “The silt fences can only do so much,” she says. “And site developers aren’t always attentive as they should be.”

Mark Senior, an engineer in Raleigh’s stormwater department, says like Wake County, the city is purchasing land for buffers to keep pollutants out of waterways. The city is also preserving private, abandoned lakes that would otherwise be sold to developers. And homebuilders are required keep runoff at the same level it was before the land was developed, or pay a fee for the state to do it.

“We’re trying to keep the situation from getting worse,” Senior says. “Somehow we have to accommodate growth and reduce pollution at the same time.”