On September 30, EPA issued proposed rules under the Clean Air Act that would regulate GHG emissions from stationary sources—e.g., power plants and refineries—for the first time. The proposal would likely require the application of at least some type of GHG emission limiting technology to all new and modified stationary sources that emit GHGs at large volumes. In terms of the volume of emissions that would trigger regulation, EPA has proposed adjusting the 100- or 250-ton threshold that applies to "criteria pollutants" to 10,000 or 25,000 tons for GHGs. Also, the proposed regulations would require the inclusion to GHG emission requirements in Title V permits for major sources, and existing major sources would have to address this new issue when their permit is up for renewal.

The fact sheet issued by EPA for the proposal indicates EPA's belief that the proposed rule will affect approximately 3,100 facilities that may not be otherwise subject to Clean Air Act emission control requirements, specifically including a large number of municipal solid waste landfills.

A 60-day public comment period will be triggered when EPA's proposal is published in the Federal Register.