SMITHFIELD — If you've ever driven past a junkyard of old tires, you know they can smell bad, look awful and attract bugs. Scientists at NC State University are teaming up with a local business and a local farmer to put your old tires to good use. Believe it or not, what used to be an eyesore can actually be good for the environment.

If you've put new tires on your car in the past year, there's a good chance the old ones are in Gail Dunn's back yard. The Johnston County family is allowing state workers to try a new livestock waste filtration system using old tires as the primary ingredient.

Once the bundles are in place in this giant lagoon, waste water from the family's hog farm will be flushed through three filtering systems.

"By the time it goes through the tires the third time, it will actually, the water will come out rather clear," Dunn explains, "and they will add bacteria in the lagoons that will help aid this process."

The cleaner leftover water can then be sprayed onto nearby fields. The solids can be sold as fertilizer.

Until now, the tires belonged to Tire Recycling, Inc., a Richmond based company that has taken some heat because of its storage facility near Clayton. The company says this project shows that old tires should be put to use, instead of being thrown away.

"There's so many tires in all these piles laying around in North Carolina and Virginia, everywhere really," says job supervisor Jim Dix. "You have a mosquito problem, with the environment and everything. It's going to help that also."

The system should be up and running by early summer. If the benefits are worth the cost, designers say old tires could be golden for hog farmers statewide.

Farmers say the bundles also take up less space than typical filtering systems. The system on the Dunn farm will hold more than one million old tires.