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General Conformity

General Conformity Training Module 3.4: Federal Agencies' Presumed to Conform Actions

Words that are shown in bold and italics are defined in the Glossary.

In developing the list of exempt actions, EPA identified a number of actions that it believed would not result in foreseeable emissions above the de minimis levels. EPA realized that the list was not exhaustive and allowed federal agencies to develop their own list of actions that are presumed to conform. To publish a list of presumed to conform actions, the federal agency must show that the emissions meet at least one of the following criteria:

  • The emissions from the action would be below the de minimis levels;
  • The emissions from the type or category of action are included in the SIP/TIP; or
  • Show that emissions from the type of action would not:
    • Cause or contribute to any new violation of any standard in any area;
    • Interfere with the applicable SIP/TIP for the maintenance of any standard;
    • Increase the frequency or severity of any existing violations of any standard in any state; or
    • Delay the timely attainment of any standard or any required interim emission reduction or other milestone in any area.

To create the final list, federal agencies would develop a draft list and undetake a process to receive and consider comments. This includes sharing the draft list with appropriate EPA offices and state and tribal agencies, publishing the list in the Federal Register, taking comment of the draft, and providing notice of the final list. The Federal Aviation Administration has published a list of actions that it presumed to conform. See 72 FR 41565. (16 pp, 716 K, About PDF)

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The federal agency can also place limits on the type of actions that are presumed to conform. The agency could limit the size of the activity to ensure that the emissions are below the de minimis levels, or limit the geographic application of the action to ensure that the action is included in the SIP/TIP. The geographic limit could be a single nonattainment area or as small as a single facility.

If an action involves more than one of the activities that are listed as presumed to conform, EPA regulations allow federal agencies to exempt only one activity with no further analysis. If the emissions from the other presumed to conform activities are added and the total of the direct and indirect emissions for that combination of activities is below the de minimis level, the combination of activities is considered to be presumed to conform. In other words, more than one presumed to conform activity can be cited aas long as the sum of all the emissions from the presumed to conform activities do not exceed the deminimis levels.

The EPA has established an alternate method for determining conformity at federal facilities. Under this approach, a federal facility would work with the state, tribal, or local air quality agency to set an emission budget for the facility. As long as the emissions at the facility remained within the budget, any action would be “presumed to conform.” If an action would result in the facility exceeding its emission budget, the action would have to undergo a standard conformity evaluation. Details of the facility emission budget approach are provided in a Module 3.5.

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