What's being done to clean up hog farming operations in places like Iowa and North Carolina and others where the industry is quite large?

Dear EarthTalk: What's being done to clean up hog farming operations in places like Iowa and North Carolina and others where the industry is quite large? I've heard horrific stories about man-made "lagoons" of animal waste spilling into and fouling rivers and groundwater and the like.

— John Schmid, Fremont, California



Hog farming has always been a messy business, but surging demand for pork in recent years has exacerbated an already foul problem: dealing with the continual production of the bodily waste of thousands of animals. Pigs are kept in tight quarters and their waste is channeled into huge open-air lagoon pits and sprayfields. The lagoons can rupture during heavy rains, unleashing a torrent of bacteria- and virus-laden feces and urine into nearby groundwater, lakes and streams. Likewise, sprayfields, where some farmers discard animal waste by spraying it over otherwise unused land, can pollute surrounding waterways and contaminate drinking water. Another side effect is air pollution: The lagoons and sprayfields emit methane (a leading greenhouse gas) and ammonia (a respiratory irritant) into the atmosphere, the foul odors sullying the air quality — and neighbors' quality of life — for miles around.

The problem has been especially bad in North Carolina, where the number of hogs raised has gone up fourfold in the last two decades — hog farmers there now raise and slaughter some 10 million hogs a year. In 1995, a hog waste lagoon overflow at Ocean View Farms in North Carolina sent 20 million gallons of hog waste into the New River, causing massive fish kills and contaminating drinking water in several neighboring communities. And the torrential rains and flooding that accompanied 1999's Hurricane Floyd wreaked havoc on hog farm waste lagoons and surrounding ecosystems across North Carolina.

But while hog farming has a deservedly bad reputation, that may all change thanks to farmers, activists, researchers and policymakers who are working hard to reduce the negative environmental impacts of the business and even capitalize on the waste itself. Pioneering research conducted at North Carolina State University has showed that technologies were already available to not only reduce hog waste pollution but to use it to grow crops like duckweed that can be converted into carbon-neutral, fuel-grade ethanol.

Meanwhile, an economic analysis by the non-profit Environmental Defense Fund (EDF) found that North Carolina could gain 7,000 jobs and add $10 billion to its economy if the hog industry there were to move to more innovative systems for treating waste. In its report, EDF stresses the importance of incentives and cost-share programs to help make such new systems affordable for the farmers who need them.

Citing this and other research, along with public outcry over waste lagoon overflows, North Carolina lawmakers passed the Swine Farm Environmental Performance Standards Act in 2007. The landmark law makes North Carolina the first state to ban the construction or expansion of waste lagoons and sprayfields on hog farms and helps hog farmers with up to 90 percent of the costs incurred by upgrading to more sustainable waste management systems. The law also funds a swine farm methane capture pilot program that will have some 50 hog farms generating electricity from their animals' emissions by September 2010. Time will tell whether North Carolina's trailblazing on the issue will influence lawmakers elsewhere.

CONTACTS: "Tiny Super-Plant can Clean Up Hog Farms and Be Used for Ethanol Production," NC State University, blogs.lib.ncsu.edu/cnrnews/entry/tiny_super_plant_can_clean; EDF, www.edf.org.