Section 110(a) Element | Summary of Element | Guidance Narrative | |
§110(a)(2)(D) | Interstate Transport | To address prongs 1 and 2 of section 110(a)(2)(D), the state’s submission should include an assessment whether or not emissions from SO2 sources located close to state borders (e.g., within the 50-km modeling domain used to assess source-specific SO2 impacts35) have associated interstate transport impacts and if so, address the impacts. The assessment might include, but is not limited to, information concerning emissions in the state, meteorological conditions in the state and the potentially impacted states, monitored ambient concentrations in the state and the potentially impacted states, the distance to the nearest area that is not attaining the NAAQS in another state, and air quality modeling. For areas designated as unclassifiable, this assessment could also be informed by the analysis conducted to satisfy 110(a)(1) maintenance SIP requirements.1 | |
§110(a)(2)(D)(i)(I) Interstate transport as it relates to significant contribution to nonattainment and interference with maintenance | contain adequate provisions (i) prohibiting, consistent with the provisions of this subchapter, any source or other type of emissions activity within the state from emitting any air pollutant in amounts which will (I) contribute significantly to nonattainment in, or interfere with maintenance by, any other state with respect to any such national primary or secondary ambient air quality standard, or
| EPA has proposed several rules that will or may reduce emissions of SO2, such as the CSAPR, the Industrial Boilers MACT, and the MATS. The emissions reductions achieved under these rules should result in reduced impacts from transported SO2 emissions and states should consider these measures, among others measures, in fulfilling the section 110(a)(2)(D)(i)(I) requirements. | |
§110(a)(2)(D)(i)(II) Interstate transport as it relates to PSD and visibility | (II) interfere with measures required to be included in the applicable implementation plan for any other State under part C of this subchapter to prevent significant deterioration of air quality or to protect visibility,
| Under section 110(a)(2)(D)(i)(II), the PSD sub-element (prong 3) may be met by the state’s confirmation in a SIP submission that new major sources and major modifications in the state are subject to PSD and (if the state contains a nonattainment area for the relevant pollutant) NNSR programs that implement the 2010 1-hour SO2 NAAQS.36 The sub-element providing for protection of visibility (prong 4) under section 110(a)(2)(D)(i)(II) may be met by the state’s confirmation that an approved regional haze SIP (or FIP) is in place. The development of the regional haze SIPs occurred in a collaborative environment among the states. Through this process, the states coordinated on emissions controls to protect visibility on an interstate basis. The regional haze rule also specifically requires that a state participating in a regional planning process include "all measures needed to achieve its apportionment of emission reduction obligations agreed upon through that process."37 We anticipate that an approved regional haze SIP (or FIP) addressing this requirement will ensure that emissions from sources within the state are not interfering with measures to protect visibility in other states. | |
§110(a)(2)(D)(ii) Interstate and international pollution | (ii) insuring compliance with the applicable requirements of sections 126 and 115 (relating to interstate and international pollution abatement); | Section 126(a) of the CAA directs each SIP to include provisions requiring a new or modified source to notify neighboring states of potential impacts from the source. States with SIP-approved PSD programs should have a regulatory provision in place, consistent with 40 CFR 51.166(q)(2)(iv), that requires such notification of other state and local agencies……Sections 126(b) and 126(c) of the CAA affect a state only if the Administrator has been petitioned to make a finding of violation that is related to either interstate transport or international transport of emissions from sources in the state. Thus, unless a state has been the subject of such a petition, the state has no continuing obligations under sections 126(b) or 126(c). Section 115 of the CAA authorizes the Administrator to require a state to revise its SIP under certain conditions to alleviate international transport. Because there are no pending actions pursuant to section 115 of the CAA, at this time EPA has no reason to approve or disapprove any existing state rules with regard to section 115 provisions. | |
VI. Transition from the existing SO2 NAAQS to a revised SO2 NAAQS
In implementing the new 1-hour SO2 NAAQS, states will need to insure that the health
protection provided under the prior SO2 NAAQS continues to be achieved as well as maintained.
This means that states should continue implementing attainment and maintenance SIPs
associated with the prior 24-hour and annual primary SO2 NAAQS until such time as they are
subsumed by any new EPA-approved SIPs reflecting planning and control requirements
associated with the new NAAQS. In the final SO2 NAAQS, EPA provided that the prior 24-hour and annual primary SO2
NAAQS will remain in effect for one year following the effective date of the initial area
designations under section 107(d)(1) for the new SO2 NAAQS before being revoked in most
attainment areas. (40 CFR 50.4(e)). Any existing SIP provisions under CAA sections 110, 191
and 192 associated with the annual and 24-hour SO2 NAAQS would need to remain in effect,
even after the 24-hour and annual primary SO2 NAAQS are no longer in effect, including all
currently implemented planning and emissions control obligations. …This will ensure that both
the new nonattainment NSR requirements and the general conformity requirements for a revised
standard are in place so that there will be no gap in the public health protections provided by these two programs. It will also ensure that all nonattainment areas under the annual and/or 24-
hour NAAQS and all areas for which SIP calls have been issued will continue to be protected by
currently required control measures.
It is important to understand that for PSD purposes, even after the time that the annual
and 24-hour SO2 NAAQS are no longer in effect, the annual and 24-hour SO2 increments
contained in the CAA and PSD regulations will remain in effect. Thus, the owner or operator of
a new or modified source will still be required to demonstrate compliance with the annual and
24-hour SO2 increments, even when the corresponding SO2 NAAQS no longer apply. The
annual and 24-hour increments are established in section 163 of the CAA. Thus, they remain
applicable even after EPA has revoked the SO2 NAAQS for the annual and 24-hour averaging
times. EPA does not believe that it can eliminate the annual and 24-hour SO2 increments
without appropriate legislative changes to the statutory SO2 increments.
(pp 32-33: http://www.epa.gov/airquality/sulfurdioxide/pdfs/DraftSO2Guidance_9-22-11.pdf )
If a state believes that its existing (already approved) infrastructure SIP is adequate with
respect to one or more section 110(a)(2) infrastructure elements (or sub-elements), then the
state's SIP submission may be a certification that the existing SIP contains provisions that fully
address those section 110(a)(2) infrastructure elements (or sub-elements) as applicable for the
2010 1-hour SO2 NAAQS.26 (26 This certification does not serve as a demonstration for purposes of CAA section 110(l) that the state has in fact
attained and maintained the 1-hour SO2 NAAQS. That demonstration, which is part of a required attainment plan
for unclassifiable areas, is specific to the 2010 1-hour SO2 NAAQS and is addressed elsewhere in our
implementation guidance.)
Two elements identified in section 110(a)(2) include requirements that are not governed
by the 3-year submission deadline of section 110(a)(1). The requirements pertain to part D, of
title I of the CAA, which addresses plan requirements for nonattainment areas. Therefore, the
following section 110(a)(2) elements are considered by EPA to be outside the scope of
infrastructure SIP actions: (1) section 110(a)(2)(C) to the extent it refers to permit programs
(known as "nonattainment new source review") required under part D; and
(2) section 110(a)(2)(I) in its entirety. EPA does not expect infrastructure SIP submittals to
include regulations or emission limits developed specifically for attaining the relevant standard.
Those submittals are due at the time the nonattainment area planning requirements are due
(18 months following designation). (B-2: http://www.epa.gov/airquality/sulfurdioxide/pdfs/DraftSO2Guidance_9-22-11.pdf )