The NAM's successful challenge to EPA's authority to regulate virtually all manufacturers that emit greenhouse gases was sent back from the Supreme Court to the U.S. Court of Appeals for the D.C. Circuit to determine what to do with regulations that are still printed in the Code of Federal Regulations, but that exceed EPA's regulatory authority. All of the parties that challenged EPA's authority, including state governments, industry associations, and public interest groups, filed a motion with the court, as has EPA, recommending what to do next.
EPA's motion proposed that the court declare the "regulations under review are vacated to the extent they require a stationary source to obtain a PSD [or Title V] permit if greenhouse gases are the only pollutant [that would trigger construction or modification review." It also says the court should direct it to rescind or revise the regulations to reflect the Supreme Court's decision. The agency does not believe it should establish a de minimis threshold for greenhouse gas regulation, but instead wants to rely on the 75,000 tons per year threshold currently on the books.
Industry's motion, by contrast, argued that the Court invalidated EPA's regulations to the extent they "treat greenhouse gases as a pollutant for purposes of defining" PSD and Title V applicability. As a result, EPA must vacate those rules, namely the Tailoring Rule, the Timing/Triggering Rule (to the extent EPA relied on it), and other challenged rules it relied on. EPA's interpretation of its authority was neither compelled nor allowed by law, so in effect it must start over. It should also decide on a de minimis threshold for regulation.
Final briefs in response to each motion were filed November 21, 2014.
On April 10, 2015, the court issued an amended order that:
"(1) the regulations under review
(including 40 C.F.R. §§ 51.166(b)(48)(v) and 52.21(b)(49)(v)) be vacated to the extent they
require a stationary source to obtain a PSD permit if greenhouse gases are the only pollutant (i)
that the source emits or has the potential to emit above the applicable major source thresholds, or
(ii) for which there is a significant emissions increase from a modification; (2) the regulations
under review be vacated to the extent they require a stationary source to obtain a title V permit
solely because the source emits or has the potential to emit greenhouse gases above the
applicable major source thresholds; and (3) the regulations under review (in particular 40 C.F.R.
§ 52.22 and 40 C.F.R. §§ 70.12, 71.13) be vacated to the extent they require EPA to consider
further phasing-in the requirements identified in (1) and (2) above, at lower greenhouse gas
emission thresholds."
The court also ordered EPA to rescind or revise the applicable rules "as expeditiously as practicable," and to "consider whether any further revisions to its regulations are appropriate in light of UARG v. EPA . . . and if so, undertake to make such revisions."