On July 28, 2015, the United States Court of Appeals for the
D.C. Circuit held that EPA's Cross State Air Pollution Rule
("CSAPR") over-regulates over a dozen
states. Although the rule was generally upheld by the U.S.
Supreme Court in 2014, the Court remanded the case to the D.C.
Circuit for further review in light of the Supreme Court's
decision. In particular, the Supreme Court's remand to the D.C.
Circuit allowed petitioners the opportunity to bring as-applied
challenges to CSAPR to demonstrate that the rule regulated
emissions beyond the point necessary to bring all downwind states
into attainment with the national ambient air quality standards
("NAAQS").
On remand, industry and the petitioning States argued that
certain of EPA's Phase II emission budgets (which now take
effect in 2017) exceeded EPA's authority because they required
more emissions reduction than necessary to attain and maintain the
NAAQS in all of the relevant downwind states. The D.C.
