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Introduction UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 10

December 19, 2014 1200 Sixth Avenue, Suite 900 Seattle, WA 98101-3140

Idaho's Part D Major New Source Review Rules David C. Bray, Senior Air AdvisorDIJ Office ofAir, Waste and Toxics Docket EPA-R10-0AR-2014-0477 OFFICE OF AIR, WASTE, AND TOXICS

On November 4, 2014, EPA Region 8 proposed to disapprove the Wyoming Part D nonattainment area new source review (NNSR) rules based on a determination that the Wyoming rules, which incorporate byreference 40 CFR 51.165 (EPA's regulations for State Implementation Plan (SIP) NNSRrules), did not comply with several Clean Air Act requirements, including sections 110(a)(2)(C), 110(a)(2)(A) and 172(c)(5). 79 FR 65362. Idaho's SIP approved Part D NNSR rules currently incorporate byreference 40 CFR 51.165 (as well as all of40 CFR part 51, subpart I) into IDAPA 58.01.01.107.03. Idaho annuallyupdates its adoptionbyreference ofthese EPA rules and EPA Region 10 is proposing to approve the State's July 1, 2013, update to this incorporationbyreference. Background EPA's requirements for SIP permit-to-construct programs, including the Part D NNSR program, are contained in 40 CFR part 51, subpart I, and specifically, in40 CFR 51.160 through 51.166. The requirements for nonattainment area permitting are found in 51.165(a), but this section does not stand alone and is part ofa series ofsections that together, comprise the requirements for approvable SIP permit-to-construct programs (e.g., 51.161 spells out the requirements for public notice and comment; 51.164 the requirements for stack heights and dispersion techniques). Importantly, the provisions ofsubpart I are not written in the form ofan implementable permittingrule which applies to the owner or operator ofsources who wish to construct or modify, butrather they are requirements that a State must meet in order to get its permitting rules approved as part ofthe SIP. In contrast to the requirements for NNSR, there are both SIP PSD requirements in 40 CFR 51.166 and Federal PSD regulations in 40 CFR 52.21, the latter being an implementable permittingrule that applies in States that do not have an approved SIP PSD rule. For a variety ofreasons, many States incorporate 40 CFR 52.21 into Staterules as the State PSDprogram. However, EPA does not have a similar implementable NNSR permittingrule that can be directly incorporated byreference into State rules. As a result, some States have incorporated byreference all or parts of40 CFR 51.165 into State rules for purposes ofNNSR. Analysis Unlike the Wyoming rule, which simplyincorporates byreference the planningrequirements of 40 CFR 51

.165 and does not link the federal permittingrequirements directly to Wyoming's existingpermittingrules, Idaho has adopted a complete State permittingrule that includes provisions that are specifically applicable to sources locating in nonattainment areas, including Stateprovisions specifying the permissible location ofoffsets (see IDAPA 58.01.01.200 through 228 and specifically 204 PERMIT REQUIREMENTS FORNEW MAJOR FACILITIES

. OR MAJOR MODIFICATIONS IN NONATTAINMENT AREAS). These provisions make clearthat no source may commence construction ofa new major facility or a major modification in a nonattainment area without obtaining a construction permit from the Idaho Department of Environmental Quality (IDEQ). IDAPA 58.01.01.204 also points to IDAPA 58.01.01.202 for application requirements and to IDAPA 58.01.01.209 for administrative processing requirements. Importantly, IDAPA 58.01.01.204 clearly states that "Theintent ofSection 204 is to incorporate the federal nonattainment NSR rule requirements." IDAPA 58.01.01.204 then goes on in subsection .01 to specify exactly which provisions from 40 CFR 51.165 are incorporatedbyreference for the purposes ofSection 204. The effect ofthe statement ofintent and the identification ofspecific provisions makes clear that these provisions of40 CFR 51.165 are requirements ofldaho's Part D NNSRpermitting program. Because Idaho's reliance on 40 CFR 51.165 as part ofits Part D NNSR program is part ofan overall construction permittingprogram that imposes additional requirements on new and modified major sources located in nonattainment areas, and because Idaho's incorporationby reference ofspecific provisions from 40 CFR 51.165 at IDAPA 58.01.01.204 is clear with respect to the intent ofthe State to adopt the permittingrequirements as State law applicable to sources locating in nonattainment areas, the concerns raised inthe proposed action on Wyoming's incorporation byreference of40 CFR 51.165 are not present in Idaho's rules.