EPA Region 6’s proposed action (1) outlines an alternative interpretation under consideration regarding the permissibility of affirmative defense provisions in the State Implementation Plans (SIPs) of states located in Region 6 that departs from the EPA’s 2015 policy on this subject; and (2) proposes to withdraw a SIP Call issued to Texas in 2015 based on a finding that the affirmative defense provisions in the SIP for the state of Texas applicable to excess emissions that occur during certain upset events and unplanned maintenance, startup, or shutdown activities are adequately protective and do not interfere with any applicable requirement of the Clean Air Act (CAA) such that they would be consistent with the newly announced Region 6 alternative interpretation if adopted.

• Frequently Asked Questions: EPA Region 6’s Proposed Action (PDF)(3 pp, 446 K)