Excess emissions caused by an unavoidable emergency, a malfunction, or nonroutine repairs of an emissions unit including pollution control equipment or process equipment constitute an affirmative defense, when asserted under regulations adopted under Alaska Stat. § 46.14.140, to an action brought for noncompliance with a technology-based emission standard. This section does not limit the department’s power to enjoin the emission or require corrective action. This provision is in addition to any emergency or upset provision contained in an applicable requirement.