EPA Accepting Comments on Revisions to Idaho’s SIP

The EPA is now accepting comments until February 10, 2014, on its proposed actions regarding Idaho's submitted SIP revisions. Idaho advanced several SIP revisions, primarily related to pm2.5 but also to CO2, through its state rule-making process and then submitted them for EPA approval in early 2013.    EPA proposes to approve some parts, disapprove other parts, and take no action regarding still other parts of Idaho’s changes.

The parts that EPA proposes to approve include “SIP strengthening” for partially regulating pm2.5 by adopting revisions to 40 CFR 51.165, and what EPA terms “housekeeping” changes like modifying the definition of “significant” pm2.5 emissions to align with current federal definitions.  Because the D.C. Circuit vacated EPA’s earlier rules for implementing pm2.5 NAAQS and EPA is currently working on new rules, EPA is only approving those changes to Idaho’s SIP that EPA deems “SIP strengthening.”

EPA proposes to disapprove certain pm2.5 nonattainment NSR regulations that Idaho had initially proposed to incorporate into state law by reference to the federal regulations.  When the D.C. Circuit vacated those federal regulations, Idaho notified EPA that it would work to remove them from its state law.  Thus EPA evidently aims to approve that removal by disapproving Idaho’s earlier request.

EPA proposes to take no action regarding Idaho’s proposal to incorporate by reference federal rules that would defer regulation of CO2 emissions from “bioenergy and other biogenic sources” under PSD and Title V programs.  EPA had previously deferred such regulation for three years, but the D.C. Circuit vacated that deferral in 2013.  Idaho proposed to also defer such regulation and EPA now proposes to “take no action” on that deferral, at least until the D.C. Circuit’s ruling becomes effective on issuing its mandate (which has not yet happened).  This proposal to “take no action” might mean that such CO2 emissions are now arguably subject to PSD and Title V programs through Idaho state law.  Evidently EPA treats its deferral rules as currently valid under federal law, but declines to allow Idaho to adopt them as a matter of state law.

Although EPA’s proposed actions are “SIP strengthening” regarding pm2.5 and ostensibly subject certain sources to CO2 permitting requirements through Idaho state law, EPA proposes that its actions are not significant regulatory actions and have no federalism implications.