The number one crop in North Carolina used to be tobacco. Today it is hogs. The state has 10 million pigs, more than triple the number it had in 1985. They are the backbone of an $8 billion per year industry that employs 46,000 people. At issue is hog waste, 19 million tons of it a year, largely stored in open storage earthen pits called lagoons. Citizens fear that the lagoons can leak or overflow, contaminate ground water, and pollute the air. In 1997 the state declared a moratorium on new lagoons. Three years later the two largest hog producers signed a $17.3 million agreement with North Carolina to advance new technologies that address environmental and health concerns. This is no laboratory exercise. Field experiments at farms are evaluating performance and cost of sixteen new technologies. VOA's Rosanne Skirble visited a test facility on a farm in Zebulon, North Carolina that has put a lid on the lagoon.
Julian Barham walks on water. Actually what he has done is to cover the hog waste lagoon on his 4,000-sow farm. The system is called an ambient digester. Mr. Barham inspects it every day by walking around and on it. ?There are several materials that you can use,? he says. ?The high-density polyethylene was the cheapest material that we thought would do a good job, and we know that it lasts quite a good while. The only thing that eventually bothers it is UV rays, which will attack it and it will break down over time.?
The cover stretches over the lagoon kind of like a gigantic waterbed. It traps odor in and keeps rain water out.
?Ours came in 23 foot [7 meter] wide rolls of material,? he explains. ?And the company we bought it out just rolled it out, seamed it together and just pulled it over the lagoon. And then all the way down the edges it is anchored down and buried in a trench so that they stay down. We have had some pretty big windstorms since we've had the cover on and it doesn't bother [it] at all. There is a pipe right there. Now you are on the water!?
Mr. Barham has been in the hog business for more than 25 years. He, like all other farmers, flushed the waste from the hog houses into open ponds or lagoons, but he says in recent years there have been new neighbors to consider.
?We have a lot of people who are moving into our neighborhood,? he says. ?It is not rural area anymore like it used to be.?
Mr. Barham took advantage of grants from private industry and the state to make some changes. The covered lagoon was just a start.
?And of course one thing led to another. We added a covered lagoon and it cost quite a bit of money and in the process you are producing methane gas. Well, I said, if you are producing gas, you might as well use it and so we put in a generator to produce the electricity. Then we still had the issue of the [excess] water after it went in the digester, so we added the greenhouses hoping to use some of the water to keep us from having to irrigate so much."
Farmers spray excess wastewater on their fields as fertilizer, but the nutrient rich agricultural runoff can pollute rivers and streams. Much of the excess on the Barham farm is pumped into the greenhouse to grow hydroponic tomatoes, providing an additional source of income.
The new technology has its downside and the major drawback is cost. Mr. Barham has borrowed more than $500,000 to put the lagoon cover and greenhouse in place. And he fears the experimental approach may not work as a long-term solution to waste management.
"And until the regulators sign off on some of this technology you don't know when you put it in whether you can use it or not,? he says. ?Like in my case if they find in my case some other technology they think is better and that ours is bad, all of the extra money I have spent may be scrapped and totally wasted."
Mr. Barham says he is pleased with the results so far, but he adds that any new technology must be adapted to farm needs and the farmer's wallet. The report evaluating new hog waste technologies including the systems employed on this farm is expected in July.