EPA Revises Air Permit Policy for Aggregating Facility Changes

The NSR permitting program was established as part of the 1977 Clean Air Act Amendments. This preconstruction permitting program ensures air quality is maintained when factories, industrial boilers and power plants are built or modified. The program ensures that state-of-the art emission control technology is installed at new plants or existing plants that are undergoing a major modification.

In addition to directing facilities and permitting authorities to combine emissions from plant modifications only when those activities are substantially related, the new final rule also specifies the following:

• For emissions to be aggregated, changes must have more in common than timing alone or just supporting the plant’s overall basic function.
• Plant modifications that are separated by 3 or more years will be presumed not to be substantially related.

This rule finalizes one of three parts of a September 2006 proposal. EPA is withdrawing the options for “debottlenecking” that were included in the proposed rule and is taking no action on the proposal that would enable emissions decreases to be factored into the first part of the test used to determine whether NSR applies to a facility making a change.