NC State Center Developing Better Ways To Manage Animal Waste

Each of its "curlers" is coated with beneficial bacteria hungry for nitrogen and phosphorus, two nutrients found in animal waste. When liquid hog waste is pumped through the filter on its way from a barn to a storage lagoon, the bacteria eat large amounts of the nutrients, significantly reducing how much ends up in the lagoon. That reduces both the odor and the risk of nutrient runoff harming the environment.

The filter is one of many new animal-waste technologies being evaluated by Williams and fellow scientists at North Carolina State University's Animal and Poultry Waste Management Center. The center was established in 1994 to promote new and better ways to reduce the cost and environmental impact of animal-waste management.

Waste from large hog and poultry farms has been blamed for polluting surface waters, contaminating wells, creating noxious odors, and discharging ammonia into the air. Treating and disposing of the waste costs farmers tens of millions of dollars each year.

To address those problems, the center supports research by scientists at NC State and other institutions to develop new waste technologies. It also assigns scientists and economists to evaluate the effectiveness of technologies already commercially available. Test results are made public through the center's Technology Evaluation and Demonstration Program, supported by the N.C. Department of Environment and Natural Resources.

In addition to the new biofilter, made by the Canadian firm Ekocan Ltd., other animal-waste technologies being developed or evaluated through the NC State center include:

An electronic "nose" that measures the potency and chemical composition of odors from animal waste and other sources;

Research into ways to manipulate the diet of livestock to reduce nutrient amounts in their waste. This includes efforts to develop a new line of feed corn that is low in phytate phosphorus. When livestock digest the corn, the phosphorus is absorbed into their bodies and not put back into their waste;

Evaporative cooling technologies for odor dispersion and odor washing. These technologies have been shown in tests to cost-effectively reduce waste odors;

New stable-isotope technology for testing surface and well water. "The beauty of this technology is that it allows us to distinguish between nutrients from fertilizer, swine waste, poultry waste, dairy waste and municipal septic," says Williams.

Legislation introduced in Congress this spring by U.S. Reps. Bob Etheridge of Lillington, Bill Hefner of Concord and Eva Clayton of Littleton would make NC State's center the focal point of nationwide research into the effectiveness of commerically available technologies for managing animal waste. Among other things, the legislation would give NC State $2 million to conduct field research to evaluate technologies being developed at the center.

"This money will help us significantly shorten the time between technology development and application," Williams says. "We need to aggressively address the animal waste situation in this state, and this is a way to get proven technology into the field and have a positive impact."

The center operates on an annual budget of about $1 million, most of which is earmarked for research. Funding comes mainly from federal and state government, but also from membership fees from the center's 15 academic, civic and corporate members. Much of the center's research is conducted at its $1.2 million testing and evaluation facility off Lake Wheeler Road in Raleigh. U. S. Rep David Price of Chapel Hill, a longtime supporter of the center and its research, helped procure the initial federal funding for that facility.