An emergency constitutes an affirmative defense to an action brought for noncompliance with a technology-based emission limitation contained in an Title V renewable operating permit if the emergency is demonstrated through properly signed, contemporaneous operating logs, or other relevant evidence that establishes the following: an emergency occurred and that the permit holder can identify the cause of the emergency; the source was properly operated at the time of the emergency; the permit holder took reasonable steps to minimize levels of emissions that exceeded emission standards during the emergency; and the permit holder submitted notice of the emergency (containing a description of the emergency, any steps taken to mitigate emissions, and corrective actions taken) to the Department of Environmental Quality within two working days after the emission limitation was exceeded due to the emergency. In any enforcement proceeding, the permit holder seeking to establish the occurrence of an emergency has the burden of proof. The bill would apply these affirmative defense provisions to noncompliance with an emission limitation in a permit to install or permit to operate issued under Section 5505, or any rule promulgated under Part 55.