JOHNSTON COUNTY, N.C. — Consider this: Large industry and electric companies deposit 25 percent of all the nitrogen in the air. That is only 2 percent more than all of the nitrogen coughed out by every car and truck on the road. Hog waste is not far behind, responsible for 20 percent of the nitrogen in our air.

A hog farm near Raleigh is getting national attention for the way it handles ground pollution and air pollution.

The electric generator generated by hog waste cranks out about 90 kilowatts of power. That is enough to power five to 10 regular homes.

"All of our waste flows into a lagoon which happens to be covered and it's considered an anaerobic digester," hog farmer Julian Barham said.

Barham has basically turned his hog lagoon into a waste treatment plant, much like cities have. Biological activity takes place, converting the hog waste into methane that he burns in his generator to power his farm.

Barham's farm is near the Wake/Johnston county line. Experts from around the world visited the farm Monday to find out more about the technology.

"Right now we are getting about a 93 percent breakdown on our solids, so that's working pretty good," he said.

The covered lagoon has been working for 7 years. Barham has not had to clean it out. In fact, he said there really no maintenance at all. Experts from around the world visited the farm Monday to find out more about the technology.

"We don't do anything to it but walk around it occasionally and make sure that nothing has got it and damaged it. We've never had any problem with that," Barham said.

The covered lagoon does not pay for itself, but the waste is free and kilowatts are not, Barham said. He uses the electricity generated by the hog waste to power greenhouses where he grows tomatoes.