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Environmental Protection Agency (EPA) Tailoring Rule

Administrator: State and Local Air Agencies; U.S. Environmental Protection Agency (EPA)


Through a series of court decisions and Environmental Protection Agency (EPA) findings, greenhouse gas (GHG) became an air pollutant subject to regulation under the Clean Air Act (CAA). Subsequently, the Environemental Protection Agency (EPA) promulgated a rule to tailor the major source applicability thresholds for greenhouse gas (GHG) emissions under the Prevention of Significant Deterioration (PSD) and Title V programs of the Clean Air Act (CAA) and to set a Prevention of Significant Deterioration (PSD) significance level for greenhouse gas (GHG) emissions. This rule is commonly called the Tailoring Rule.


If Prevention of Significant Deterioration and Title V requirements had applied to greenhouse gas (GHG) at the applicability levels provided under the Clean Air Act, state permitting authorities would have been faced with processing permit applications in numbers that are orders of magnitude greater than their current administrative resources could accommodate. The Tailoring Rule was developed to make the impact of regulating greenhouse gas (GHG) under the Clean Air Act more manageable.


In March 2011, the Environmental Protection Agency (EPA) proposed a three year deferral from being subject to the permitting requirements under Title V and Prevention of Significant Deterioration for sources of biogenic CO2 only.