Economic Outlook - July 2006

Hog industry must make haste on waste systems

Hogs are North Carolina’s top agricultural product, bringing farmers more than $2 billion in 2004. That total might have been bigger if not for a nine-year-old moratorium on starting or expanding farms with more than 250 hogs. Waste spills helped prompt the cap and want of a better way to handle hog waste will keep it in place until at least September 2007. Mike Williams, director of the Animal and Poultry Waste Management Center at N.C. State University, studied alternatives and found five that work well enough. But they’re all too expensive.

BNC: What’s wrong with the way hog waste is handled?

Williams:There are environmental issues associated with the current system — emissions of ammonia, concentration of nutrients in an area that may have a limited amount of land on which to put the nutrients for crop uptake. And of course you hear about the odor issues. I don’t think we’re in an environmental crisis with the current system, but I think it is one that is not sustainable for the long term.

Isn’t the big problem waste spills?

I’m not sure how productive it is to get into finger-pointing, but the industry has many times pointed out that it is responsible for only a small fraction of the releases. Municipal and other waste systems are responsible for a much bigger share of the total. There was, of course, the one waste-lagoon rupture in 1995, in which there were several million gallons released in a short period of time into the New River. That, of course, captured a lot of attention. And then floods did result in some waste lagoons overflowing.

How has the moratorium affected the Tar Heel hog industry?

It has resulted in a plateau of production. Since about 1997, when that moratorium was enacted, the inventory of hogs has fluctuated a little bit, but it has remained at about 10 million. Some who raise hogs say that a moratorium has been a good thing. However, there’s no question — because I’ve had these people contact me — there are people who would like to expand. There are people, especially some people who historically have derived their main agricultural revenue from tobacco, who are interested in phasing into other forms of agriculture and would be interested in raising hogs.

Describe the most environmentally friendly waste system you’ve found.

It is a system that is similar to a small municipal waste-treatment system. It has a process where it separates the solids from the waste stream and also removes all of the phosphorus and kills the pathogens. Then the liquid waste is treated by a denitrification process, such that the ammonia is converted to nitrogen gas, which is inert and environmentally good. Odor-causing compounds are also oxidized.

What about the solids?

We identified an additional four systems that were above the bar for all of the environmental variables. And they involved processes as simple as composting the solids to processes as complex as gasifying the solids or incinerating them or treating them in an enclosed anaerobic digester, which would convert the nutrients in the solids to methane, which could then be converted into electricity and put back onto the grid.

How are the alternatives better than the current waste-handling system?

You would have less odor for the same number of animals in the same location. You would have fewer ammonia emissions, fewer pathogens and fewer heavy metals.

Better spill prevention?

Yes. Enclosed steel tanks instead of open-air earthen lagoons.

Why is it so hard to find a feasible fix?

The current system is inexpensive, and it is forgiving in terms of operator requirement and day-to-day maintenance. When you start incorporating systems that have pumps, blowers, technology-control components, you are adding cost. You are adding complexity. And to make that comparable economically to the existing systems is very challenging, especially if you do not have markets or incentives for products that can result from these systems.

What do you mean?

Some of these technologies were demonstrated to be able to produce electricity, to produce steam energy, to produce biodiesel fuel from manure, but the cost is not attractive. If we had some incentives and tax credits, I think it would be the catalyst that would drive the technology and improve on the technology and make it economically feasible.

How much more costly are the systems you tested?

Approximately four to five times more expensive than the existing system.

The moratorium was supposed to allow time for alternatives to be proven in the field. Is that possible by September 2007?

Yes. It’s possible but ambitious.

What if it doesn’t happen?

The General Assembly would have to address that. I have heard the moratorium would become permanent. But that would surprise me. I feel like it would be extended another five years or so.