EPA is proposing to revoke a January 2009 rule that changed the way existing industrial facilities combine upcoming construction projects to determine if Clean Air Act permits are needed, according to an agency press release.

EPA is concerned that the changes made last year to its “aggregation policy” would make the agency’s New Source Review permitting program less effective, allowing facilities to increase emissions that may impact air quality without a thorough review, according to the press release.

The new proposal responds to a petition to reconsider the 2009 rule. The 2009 rule directed facilities and permitting authorities to combine emissions from construction projects only when the changes are “substantially related,” such as having more in common than the timing of construction.

EPA is proposing to go back to its original policy, which required combining projects based on a broader range of factors. This would ensure that potential emissions increases that could harm air quality do not avoid review and the installation of state-of-the-art pollution controls.

New Source Review is a pre-construction permitting program to ensure 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.