EPA suggests maintaining GHG emissions thresholds

By Kris Bevill | February 28, 2012

The U.S. EPA has issued its proposal for the third leg of its greenhouse gas (GHG) Tailoring Rule, suggesting that emissions thresholds should remain at their current levels rather than expand to include smaller sources of GHG emissions.

The Prevention of Significant Deterioration and Title V GHG Tailoring Rule, finalized in May 2010, set in  motion a tiered approach to regulating GHG emissions from stationary sources, beginning with sources already permitted for other pollutants and gradually expanding to include other major sources of GHG emissions. The rule currently requires facilities emitting more than 100,000 tons per year of carbon dioxide equivalent (CO2e) to obtain operating permits.

In the final rule published in 2010, the EPA said it would take comments and decide by July 1, 2012, whether the emissions threshold should be lowered to includes sources emitting at least 50,000 tons of CO2e annually beginning in 2016. After reviewing the program to this point, the EPA suggested on Feb. 24 that the threshold should not be lowered, noting that state permitting authorities need more time to develop program infrastructure and increase their GHG permitting expertise before requirements can be feasibly applied to smaller sources. “After consultation with states and evaluating the process, EPA believes that the current approach is working well, and that state permitting authorities are currently managing PSD permitting requests,” the agency said in a release. “Therefore, EPA has proposed not to include additional, smaller sources in the permitting program at this time.”

Most ethanol plants are already subject to the Tailoring Rule’s requirements. According to the EPA, the rule’s current requirements cover nearly 70 percent of the GHG emissions from stationary sources. In the proposed rule announced Feb. 24, the agency also offered two approaches to streamline the GHG permitting process. One would increase the flexibility and improve plant-wide applicability limitations, known as PALs, which is a source-wide emissions limit that can be used to allow a facility to make changes without triggering PSD permitting requirements so long as emissions to not exceed the PAL limit, according to the EPA. The second streamlining approach would allow the EPA to issue synthetic minor permits for GHG emissions when a source agrees to limit its emissions to a level below the PSD threshold, giving emitters the opportunity to stave off more complicated PSD permitting requirements.

The agency is also seeking information on a variety of other aspects related to the GHG permitting process, including permitting activity and burden, the impact of lowering emissions thresholds and the development of best available control technologies (BACT) for sources of GHGs. Comments will be accepted for 45 days after the proposed rule is published in the Federal Register. The EPA will also hold a public hearing on March 20 in Arlington, Va., to discuss the proposal.