Regulating Ammonia Emissions from Agriculture: Potential Pitfalls and Limitations
Channel: Livestock & Poultry Environ. Learning Community
Date: 2015-05-14

The full proceedings paper is at: www.extension.org/72876

Currently, there is limited regulation of ammonia (NH3) emissions as a matter of federal policy.  The Clean Air Act (CAA) provides the federal authority for regulation of these emissions.  Although there are reporting requirements for NH3 under the Comprehensive Environmental Response, Compensation and Liability Act and Emergency Planning and Community Right-To-Know Act, these statutes do not provide authority to regulate emissions of NH3.  There is increasing pressure to change NH3 policy primarily due to concerns about nutrient enrichment of large water bodies, such as the Chesapeake Bay and the Gulf of Mexico. Recently, the EPA has been petitioned to list NH3 as a criteria pollutant; and this request is somewhat supported by the report from the EPA’s Integrated Nitrogen Panel to the Science Advisory Board. There is also the immediate concern of EPA’s treatment of NH3 as a precursor to fine particulate matter (PM2.5). Regulation of NH3 as a precursor to PM2.5 will make it a regulated pollutant under the CAA. It will be difficult to regulate only the ‘excess’ portion of reactive N, particularly since ‘excess’ cannot be defined as a constant. Roughly 60- 85% of NH3 emissions in the U.S. are estimated to come from agricultural sources, a sector that varies considerably from the traditional industrial sources addressed by the environmental statutes.  In fact, in most of these statutes, there is recognition that agricultural sources are different; and some regulatory exemptions are provided. Most likely, Congress did not anticipate the application of the CAA to agricultural sources or it would have included some exemptions in it as well. Nevertheless, regulation of NH3 emissions under the CAA will make it extremely difficult for EPA to consider the positive value and need for fertilizer NH3, which could have huge implications for the viability of the domestic and global food supply.