EPA opts not to lower GHG emissions threshold

By Kris Bevill | July 03, 2012

The U.S. EPA has decided not to expand its greenhouse gas (GHG) permitting requirements to include smaller sources of emissions in 2016 as was suggested in its initial Prevention of Significant Deterioration and Title V GHG Tailoring Rule, finalized in May 2010. The Tailoring Rule set in a motion a three-tiered approach to regulating GHG emissions from stationary sources, the third step being a possible expansion of the emissions threshold to include all stationary sources emitting 50,000 tons of CO2 equivalent (CO2e) or more annually. Earlier this year, the agency proposed to maintain the current 100,000 tons of CO2e emissions threshold rather than expand the number of obligated participants to include smaller sources. After consulting with states and evaluating its phase-in process, the agency finalized that proposal on July 3. In a news release, the agency said, “current conditions do not suggest that EPA should lower the permitting thresholds.”

According to the EPA, the Tailoring Rule’s current GHG emissions thresholds account for nearly 70 percent of the total GHG emissions from stationary sources. Currently, new facilities emitting at least 100,000 tons per year of CO2e are required to obtain Prevention of Significant Deterioration permits. Existing facilities with at least 100,000 tons per year of CO2e emissions that plan to make changes that will increase those emissions by at least 75,000 tons per year are also required to obtain PSD permits. Additionally, all facilities with GHG emissions above 100,000 tons per year of CO2e are required to obtain operating permits. Most ethanol plants are included under the current thresholds umbrella.


The EPA and state permitting authorities have issued 44 PSD permits addressing GHG emissions as of May 21. The permits require those facilities to implement energy efficiency measures to reduce their GHG emissions, the EPA said.