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Search still on for treating hog-waste odor, pollution

Glenn Clifton walks along the ridge of the original hog-waste holding lagoon he designed for Barham Farm (now known as Full Circle Recycle) in Zebulon, N.C., on Oct. 30.
Glenn Clifton walks along the ridge of the original hog-waste holding lagoon he designed for Barham Farm (now known as Full Circle Recycle) in Zebulon, N.C., on Oct. 30.

YADKINVILLE, N.C. – Google, of all companies, last year got into the business of hog poop.

It joined a project started by Duke University, Duke Energy and a Yadkin County farmer to pull the potent greenhouse gas methane from swine waste and use it to generate electricity or simply burn it off. The Internet giant and the university get to claim credit for offsetting the climate-changing carbon emissions generated during creation of the energy they use, and the power company is making strides toward new state requirements for generating electricity from hog waste.

Meanwhile, a couple of long-promising approaches for nearly eliminating pollution and odor from swine waste are inching closer to meeting standards that could force pork producers to retrofit them on most North Carolina pig farms.

Google? Carbon offsets? Manure to electricity? Much has changed in the 15 years since state officials first got serious about finding a cleaner way to treat the waste from North Carolina’s 9 million-plus hogs.

But much hasn’t.

“For the people out there in the communities, nothing is really happening,” said Joe Rudek, a senior scientist with the national advocacy group Environmental Defense Fund. “They haven’t really seen any changes in air or water quality.”

The problems with odor, runoff from the spray fields and spills from lagoons still plague areas where hog farms are located.

Deborah Johnson, executive director of the North Carolina Pork Council, said pork producers would embrace a cleaner, cost-effective technology.

“If there is something out there, a (technology) that is affordable to growers and qualifies for permitting by the state, we would see growers that will adopt it,” she said.

Back in 1997, the state slapped a temporary moratorium on new or expanded hog farms that used the lagoon-and-spray-field method.

In 2000, North Carolina Attorney General Mike Easley negotiated the landmark Smithfield Agreement with the state’s main pork producers in which they agreed to several concessions, including paying $50 million over 25 years for environmental projects.

They also funded a $17.1 million research quest for a new method of treating hog waste.

This new method was to “substantially eliminate” pollutants and odor and completely stop waste from leaking into streams or groundwater. The companies agreed that if one could be found that was affordable, they would install it on farms they own.

Before the official state search began, Julian Barham started tinkering with better ways to treat waste from his 4,000 or so sows at his compact farm near Zebulon, N.C.

The farm has become a complex, interconnected system that includes hogs. But somehow the long metal barns where they live feel less like the heart of the operation than simply one of several key components.

At one end of the row of barns stands an above-ground tank the size of a large house. Inside, hog waste and discarded produce are eaten by microbes that produce methane. Pathogens and odor are sharply reduced.

Regulators are keen to keep food waste out of dumps, and Barham can make use of it. He also charges tipping fees to the supermarkets that truck it in.

Heating the tank by burning some of the methane makes the digestion process more efficient. Barham also has a generator and can make power for use on the farm or to sell, though he has decided that for now it’s not economical enough to operate.

Another system removes ammonia. Some nutrients are pulled from the wastewater to grow vegetables in two greenhouses, each of which covers three-quarters of an acre.

The treated wastewater is recycled to flush the waste out of the barns into the digester, and the process begins again.

Barham said all the parts not only make the farm a better steward of the environment, but given the current market conditions for hogs, help keep it going.

“When I got started in hogs, I had 200 sows and could make a pretty decent living,” he said. “Now I’ve got 4,000 and I struggle.”


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