Date: 

Subject: 

From: 

To: 

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 of Air, 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 by reference 40 CFR 51.165 (EPA's regulations for State 

Implementation Plan (SIP) NNSR rules), 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 by reference 40 CFR 51.165 (as 

well as all of 40 CFR part 51, subpart I) into IDAPA 58.01.01.107.03. Idaho annually updates 

its adoption by reference of these EPA rules and EPA Region 10 is proposing to approve the 

State's July 1, 2013, update to this incorporation by reference. 

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, in 40 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 of a series of sections 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 of subpart I are not written in the form of an implementable 

permitting rule which applies to the owner or operator of sources who wish to construct or 

modify, but rather they are requirements that a State must meet in order to get its permitting rules 

approved as part of the 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 permitting rule that applies in States that do not have an approved SIP PSD rule. 

For a variety of reasons, many States incorporate 40 CFR 52.21 into State rules as the State PSD 
program. However, EPA does not have a similar implementable NNSR permitting rule that can 

be directly incorporated by reference into State rules. As a result, some States have incorporated 

by reference all or parts of 40 CFR 51.165 into State rules for purposes ofNNSR. 

Analysis 

Unlike the Wyoming rule, which simply incorporates by reference the planning requirements of 

40 CFR 51 .165 and does not link the federal permitting requirements directly to Wyoming's 

existing permitting rules, Idaho has adopted a complete State permitting rule that includes 

provisions that are specifically applicable to sources locating in nonattainment areas, including 

State provisions specifying the permissible location of offsets (see IDAPA 58.01.01.200 through 

228 and specifically 204 PERMIT REQUIREMENTS FOR NEW MAJOR FACILITIES . 

OR MAJOR MODIFICATIONS IN NONATTAINMENT AREAS). These provisions make 

clear that no source may commence construction of a 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 IDAP A 58.01.01.209 for administrative processing 

requirements. Importantly, IDAP A 58.01.01.204 clearly states that "The intent of Section 204 is 

to incorporate the federal nonattainment NSR rule requirements." IDAP A 58.01.01.204 then 

goes on in subsection .01 to specify exactly which provisions from 40 CFR 51.165 are 

incorporated by reference for the purposes of Section 204. The effect of the statement of intent 

and the identification of specific provisions makes clear that these provisions of 40 CFR 51.165 

are requirements ofldaho's Part D NNSR permitting program. 

Because Idaho's reliance on 40 CFR 51.165 as part of its Part D NNSR program is part of an 

overall construction permitting program that imposes additional requirements on new and 

modified major sources located in nonattainment areas, and because Idaho's incorporation by 

reference of specific provisions from 40 CFR 51.165 at IDAP A 58.01.01.204 is clear with 

respect to the intent of the State to adopt the permitting requirements as State law applicable to 

sources locating in nonattainment areas, the concerns raised in the proposed action on 

Wyoming's incorporation by reference of 40 CFR 51.165 are not present in Idaho's rules.