New rules restrict hog waste disposal

New and expanding hog farms in North Carolina will have to use innovative systems instead of traditional open-air pits to manage animal waste under new rules that go into effect Thursday.

The General Assembly passed the waste standards in 2007 to reduce air and water pollution from hog farms. State environmental regulators subsequently wrote rules to uphold the standards, and enforcement starts with the new year.

Farmers traditionally use open-air pits, known as "lagoons," to dispose of massive volumes of manure and urine. Bacteria break down solid waste in the lagoons, and liquid waste is sprayed on fields as fertilizer. But the lagoons can leak or overflow, and waste can wash into streams, polluting water and causing fish kills.

Under the new rules, new and expanding farms must install waste disposal systems that substantially eliminate odors, airborne emissions of ammonia, discharge of animal waste into rivers and groundwater and disease-carrying pathogens.

Earthen structures must be have synthetic liners to eliminate seepage. Waste systems also must have high-water alarms that automatically notify the farm's owner or manager.

Also, the rules limit ammonia emissions from storage structures, land application sites and the farm as a whole. Odor controls also are required to meet air quality standards.

Further, the new systems must be monitored quarterly for at least two years to assure that the performance standards are being met.