On March 20th, the DC Circuit upheld EPA’s June 2012 “CSAPR = BART Rule,” establishing that compliance with EPA’s Cross State Air Pollution Rule (CSAPR) will satisfy the Best Available Retrofit Technology (BART) requirements for SO2 and/or NOx under the Regional Haze Rules for electric generating units (EGUs) subject to CSAPR. Under the Regional Haze Program, EPA has issued regulations that allow the Agency to approve alternatives to BART if EPA finds that the controls are “better than BART.”

The Court also upheld EPA’s decision in that same rulemaking to rescind its determination that the Clean Air Interstate Rule (CAIR) will satisfy BART requirements (CAIR = BART) and related disapprovals of individual state SIPs that relied on CAIR = BART.

The decision comes as good news for EGUs in the East and Midwest that would otherwise have been subject to case-by-case BART determinations at the state level like EGUs in western states not subject to CAIR or CSAPR.

The National Parks Conservation Association and the Sierra Club challenged EPA’s 2012 CSAPR = BART rule on numerous grounds. Ultimately, their main claim was that the DC Circuit’s 2015 decision in EME Homer City v. EPA, remanding the CSAPR SO2 and/or NOx budgets for several states undercut the factual basis for EPA’s 2012 CSAPR = BART determination. The court and the petitioners ultimately agreed that this particular claim is now moot because in September 2017 EPA issued a new rule determining that CSAPR still = BART despite the budget remands. That 2017 rulemaking has been separately challenged by environmental groups in the DC Circuit.

Unlike EGUs in the West, EGUs in the East and Midwest have avoided protracted litigation with EPA over state case-by-case BART determinations as a result of EPA’s CAIR = BART and then CSAPR = BART rulemakings. Environmental groups have challenged all of EPA’s rulemakings that obviate the need for case-by-case BART analyses. Thus far, those efforts have been unsuccessful, but environmental groups’ challenge to EPA’s 2017 rulemaking is still pending. That challenge will be briefed this spring and summer with oral argument possible later this year. As a result, some degree of legal uncertainty remains around whether CSAPR will continue to be “better than BART.”