Beginning on January 2, 2011, U.S. EPA will begin regulating greenhouse gas (GHG) emissions from new and modified stationary sources, such as power plants, refineries, and manufacturing facilities under the Clean Air Act’s Prevention of Significant Deterioration (PSD) and Title V permitting programs. Under the EPA’s GHG Tailoring Rule, issued in May, 2010, permitting will initially focus on the largest industrial sources, i.e. those sources emitting roughly 70% of GHG emissions.

The EPA considers greenhouse gases to be a single air pollutant, defined as the aggregate group of six gases: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, per fluorocarbons, and sulfur hexafluoride.

In November 2010, just two months shy of the January effective date of the new requirements, EPA released guidance intended to assist local and state permitting authorities as they implement the GHG permitting requirements. The document purports to provide guidance to permitting agencies and industry in determining best available control technology (BACT) for GHG emissions.

Some observers have called into question the helpfulness of the guidance, which does not actually provide any specific guidance on actual BACT for GHG emissions.

Nevertheless, according to EPA, the guidance “applies long-standing PSD and Title V permitting requirements and processes to GHGs,” “reiterates that BACT determinations will continue to be a state, and project specific decision,” and “does not prescribe GHG BACT for any source type.” The guidance does emphasize, however, the importance of GHG BACT that improve energy efficiency, and points out that technologies such as Carbon Capture and Sequestration and the use of biomass may be possible GHG BACT, although economic considerations may make these technologies unlikely to be selected.

In short, there is not a lot of new, GHG-specific information in the GHG BACT guidance. The EPA emphasizes that the guidance does not provide a new approach for selecting BACT for GHG emissions. Permitting authorities are to continue using the EPA’s long standing BACT five-step process. These steps are: 1) identify all available control technologies, 2) eliminate technically infeasible options, 3) evaluate and rank remaining control technologies based on environmental effectiveness, 4) evaluate cost effectiveness of controls and energy and other environmental impacts, 5) select the BACT.

For more information on EPA’s BACT guidance for GHG, please contact Heidi Trimarco or any member of Taft’s environmental practice group.