On April 6,a group of organizations led by the Environmental Integrity Project, petitioned the U.S. Environmental Protection Agency to regulate ammonia as a criteria pollutant under the Clean Air Act, Sections 108 and 109. See the full petition.

The EPA currently regulates airborne ammonia under Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), commonly known as Superfund, and Emergency Planning and Community Right-to-Know Act (EPCRA) as a hazardous substance. The Agency for Toxic Substances and Disease Registry (ATSDR) characterizes ammonia as a toxin because exposure to airborne ammonia can result in severe respiratory effects.

Whether EPA chooses to fold ammonia emissions into the Clean Air Act may depend upon the National Air Emission Monitoring Study data-processing that is underway at the agency.

“This may shape whether or not EPA sees a need to regulate ammonia from Concentrated Animal Feeding Operations,” says Wendy Powers, Michigan State University professor and director of the Institute for Agriculture and Agribusiness (MSU Extension) and director of Environmental Stewardship for Animal Agriculture. “If it looks like there is considerable opportunity they may; otherwise they may not. But it will be a multiyear process to even get ammonia listed as a criteria pollutant, much less develop the standards through a committee. With that said, there is a real possibility it might happen.”

EPA has the authority to designate pollutants that endanger public health or welfare as ‘criteria pollutants’, and to establish protective primary and secondary National Ambient Air Quality Standards (NAAQS) for these pollutants, under Sections 108 and 109 of the Clean Air Act.

For the moment, Powers advises that you stay on top of the topic and watch for opportunities to provide input to EPA. “At this point EPA has not responded to the petition so waiting for that response is the first step,” she says.

Meanwhile, it is important for farmers and farm groups to recognize that the petition has been filed, and understand that it affects not only CAFOs but also potentially fields that receive manure due to emissions that occur during land application.

If EPA were to list ammonia as a criteria pollutant under Section 108, activities under Section 109 would follow.

These activities include setting a schedule for development of primary and secondary standards under NAAQS to protect public health and welfare. If an area (often defined as a county) exceeds the NAAQS for a criteria pollutant the appropriate permitting agency is charged with developing a State Implementation Plan  to bring the area into attainment of the standard.

This often leads to identification of sources and practices to reduce the emission of the pollutant within the affected region.

Currently there are six EPA designated criteria pollutants: 1) carbon monoxide, 2) nitrogen dioxide, 3) ozone, 4) lead, 5) sulfur dioxide, and 6) particulate matter.

Under Section 109(d) of the Clean Air Act, the EPA Administrator and independent scientific review committee must re-evaluate both the list of criteria pollutants and the NAAQS in five-year intervals. The ozone standards were recently reviewed and recommendations are expected out soon.

If the Environmental Integrity Project’s petition is successful and ammonia is listed as a criteria pollutant, the action has the potential to significantly impact food production. Agriculture (both animal and crop agriculture) is the largest source of ammonia emissions. Development of primary and secondary standards under the Clean Air Act for ammonia could mean that mitigation is required for point sources (like CAFOs) that exceed the standards.

This could also mean that some of the CAFOs will require permits under Title V. States with designated authority will oversee the permitting process and enforce standards.

“There are practices that can reduce ammonia — all with varying costs and levels of effectiveness,” notes Powers. “This spans reducing diet crude protein, to installing manure covers, applying urease inhibitors on fields, injecting manures. IF this moves forward, the best option is for EPA to propose an extensive menu of options with identified mitigation coefficients so that a farmer can determine which options fit best with the farming system.”

This petition follows a recent report from the Environmental Integrity Project that interpreted findings of an industry-funded EPA study that monitored ammonia, particulates, hydrogen sulfide, and volatile organic compounds from CAFOs across the country.