Court ruling likely to require increased air quality monitoring by livestock producers.

A federal court has upheld an Environmental Protection Agency rule governing emissions of dust in rural areas, a decision that the National Pork Producers Council says could result in livestock operations being treated as stationary air emissions sources that are required by federal and state laws to obtain emissions permits.

As a result, says NPPC, pork production operations could face monitoring for particulate matter such as dust from dirt roads and fields and for chemicals, including ammonia, that can form particulate matter. They also may be subject to Clean Air Act "new source review" requirements any time a modification or improvement to their operations is made.

At issue was an EPA decision to regulate emissions of coarse particulate matter (PM), or dust, in rural areas. NPPC argued that while EPA identified problems with coarse PM in urban areas, it failed to show any health effects associated with rural dust, which comes mostly from naturally occurring organic materials such as plants, sand and soil.

While recognizing the distinctions between urban and rural PM sources, EPA nonetheless decided to regulate agricultural operations for coarse PM. A 2002 National Academy of Sciences report found that there were no scientifically credible methodologies for estimating emissions from animal feeding operations.

According to NPPC, the U.S. Court of Appeals for the District of Columbia sided with EPA by adopting the so-called precautionary principle, which place the burden on the livestock industry to prove that its operations are not harming the public or the environment. According to the court's decision: "In assessing the scientific evidence, the [livestock organizations] have mistakenly equated an absence of certainty about dangerousness with the existence of certainty about safety."