Background

Franklin County, Idaho was designated as part of the multi-state Logan, Utah-Idaho nonattainment area for PM_2.5, effective December 14, 2009 (74 FR 58688, published November 13, 2009).

The State of Idaho submitted a revision to the state implementation plan (SIP), dated December 14, 2012, to meet the planning obligations for PM_2.5 nonattainment areas as they existed at that time (see Final Clean Air Fine Particle Implementation Rule, 72 FR 20586, published April 25, 2007).

Subsequently, on January 4, 2013, the Court of Appeals for the District of Columbia remanded the EPA's implementation rule as a result of Natural Resources Defense Council v. EPA, 706 F.3d 428 (D.C. Cir. 2013). The Court concluded that the EPA had improperly based the 2007 implementation rule for the PM_2.5 NAAQS solely upon the requirements of part D, subpart 1 of the Clean Air Act, and had failed to address the requirements of part D, subpart 4. On August 24, 2016, the EPA promulgated a revised PM_2.5 implementation rule in response to the Court decision. See, Fine Particulate Matter National Ambient Air Quality Standards; State Implementation Plan Requirements; Final Rule (81 FR 58010). 

On December 26, 2013, the EPA proposed to approve PM_2.5 control measures contained in Idaho's December 2012 plan as strengthening the SIP (78 FR 78315 (PDF)(4 pp, 261 K, About PDF)). On March 25, 2014, the EPA finalized approval of the control measures (79 FR 16201 (PDF)(3 pp, 239 K)). On July 18, 2014 , the EPA also approved the comprehensive emissions inventory of PM_2.5 and PM_2.5 precursors required under Clean Air Act section 172(c)(3). Proposal (79 FR 27543 (PDF)(4 pp, 252 K)) and final (79 FR 41904 (PDF)(2 pp, 233 K)).

In light of the court’s decision in Natural Resources Defense Council v. EPA, and the need to evaluate the Idaho submission in conjunction with the SIP submission for the Utah portion of the Logan UT–ID nonattainment area, the EPA did not make a determination whether Idaho's December 2012 SIP submission satisfied all of the statutory nonattainment planning requirements for the 2006 PM_2.5 NAAQS.

Idaho supplemented the 2012 attainment plan on December 24, 2014 to address the requirements of part D, supart 4. On January 4, 2017, the EPA approved, disapproved, and deferred actions on certain portions of the 2012 and 2014 submittals. Specifically, the EPA approved Idaho’s evaluation of, and imposition of, reasonably available control measure and reasonably available control technology (RACM/RACT) level controls on appropriate sources in the Idaho portion of the nonattainment area. The EPA disapproved the Idaho attainment plan with respect to the contingency measure requirement. The EPA deferred action on the submissions with respect to the attainment demonstration, reasonable further progress, quantitative milestone, and motor vehicle emission budget requirements to a future date. Proposal (81 FR 74741 (PDF)(10 pp, 265 K)) and final (82 FR 729 (PDF)(5 pp, 270 K)).

On August 8, 2017, the EPA approved the attainment demonstration and approved Idaho’s 2014 Motor Vehicle Emissions Budgets (MVEBs) as early progress budgets. Additionally, the EPA conditionally approved Reasonable Further Progress (RFP), Quantitative Milestones (QMs), and revised MVEBs for the Idaho portion of the nonattainment area, based on Idaho’s commitment to adopt and submit updates to these attainment plan elements within one year of the effective date of the final action. Proposal (81 FR 74741 (PDF)(10 pp, 265 K)) and final (82 FR 729 (PDF)(5 pp, 270 K)).

On September 8, 2017, the EPA approved the Idaho and Utah requests for two 1-year extensions of the moderate area attainment date from December 31, 2015 to December 31, 2017, in accordance with section 188(d) of the Clean Air Act. Proposal (82 FR 26638 (PDF)(2 pp, 226 K)) and final (82 FR 42447 (PDF)(5 pp, 236 K)).

On October 18, 2019, the EPA finalized a determination of attainment by the attainment date and clean data determination (85 FR 52983 (PDF) (4 pp, 259 K)).

On July 31, 2019, Idaho submitted a SIP revision to further address the RFP, QM, and MVEB elements that the EPA conditionally approved on August 8, 2017. On February 20, 2020, the EPA fully approved the RFP, QM and MVEB elements (85 FR 9664 (PDF) (3 pp, 317 K)).

Summary

The plan relies on measures for control of emissions from residential wood combustion and road dust. 

Rules

• City of Clifton Ordinance No. 120, August 11, 2012
• City of Dayton Ordinance #287, August 8, 2012
• Franklin City Ordinance No. 2012-9-12, Solid Fuel Heating Appliances, September 12, 2012
• Franklin County Ordinance No. 2012-6-25, Solid Fuel Heating Appliances, June 25, 2012
• City of Oxford Memorandum of Understanding, Solid Fuel Heating Appliances, October 22, 2012
• City of Preston Ordinance No. 2012-1, June 11, 2012
• City of Weston Ordinance No 2012-01, August 1, 2012

Other Control Measures

• Letter of Intent PM_2.5 Reduction, Franklin County Road Department to Department of Environmental Quality (Voluntary Measure), July 16, 2012
• Road Sanding Agreement, Idaho Transportation Department to Idaho Department of Environmental Quality (Voluntary Measure), October 25, 2012