U.S. EPA Finalizes Wisconsin SIP Revision

On August 31, 2018, the United States Environmental Protection Agency (U.S. EPA) finalized an approval of a revision to the Wisconsin State Implementation Plan (SIP) submitted by the Wisconsin Department of Natural Resources (WDNR) to U.S. EPA on November 28, 2017. The approval of this modification affects the state rule’s Prevention of Signification Deterioration (PSD) language on greenhouse gas applicability. This approval is specific to the analyses of Wisconsin sources and now aligns this state’s rules with the Federal PSD regulations and other state programs. This modification was made to reflect the changes brought about by the Utility Air Regulatory Group (UARG) vs U.S. EPA Supreme Court ruling on June 23, 2014 that were reflected in amendments to the Federal PSD regulations on August 19, 2015.

Historically, a source could be considered major based on both non-greenhouse gas and greenhouse gas regulated pollutants, potentially requiring PSD analysis and permitting for new facilities or changes at existing ones. PSD permitting applies to major sources and major modifications in areas that are designated attainment or unclassifiable for any national ambient air quality standards (NAAQS) pollutants. Facilities that triggered PSD applicability for greenhouse gases were also required to install best available control technologies (BACT) for that pollutant on new sources or on modified sources where greenhouse gas emissions would be increasing.

In the UARG vs U.S. EPA Supreme Court case, 134 S. Ct. 2427, the Supreme Court evaluated U.S. EPA’s final decision on two criteria: whether U.S. EPA permissibly determined sources may be subject to PSD and Title V requirements based only on their greenhouse gas PTE, and whether a source already subject to PSD because of other pollutants still required BACT for their greenhouse gas emissions. Following their analysis, the Supreme Court ruled that the Clean Air Act (CAA) does not necessitate U.S. EPA to require a source to obtain a PSD or Title V permit based only on the source’s potential greenhouse gas emissions. The approval of WDNR’s revision is great news for these greenhouse gas regulated only sources in Wisconsin, but this revision still upholds the greenhouse gas tailoring rule for sources considered major based upon non-greenhouse gas regulated pollutants.

What about the other states?

While this final SIP revision approval by U.S. EPA only applies to the WDNR submittal, as previously noted, this change is already reflected in the Federal PSD regulations. For states that directly implement the Federal PSD rules these changes have been in effect for several years, as is the case with most other states with Federally delegated PSD programs.

If you have any questions about what this may mean for your next project, please contact ALL4 at 610-933-5246.