[Federal Register Volume 80, Number 210 (Friday, October 30, 2015)]
[Proposed Rules]
[Pages 66862-66865]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-27594]



40 CFR Part 52

[EPA-R10-OAR-2015-0258; FRL-9936-31-Region 10]

Approval and Promulgation of Implementation Plans; Idaho: 
Interstate Transport of Ozone

AGENCY: Environmental Protection Agency.

ACTION: Proposed rule.


SUMMARY: The Clean Air Act (CAA) requires each State Implementation 
Plan (SIP) to contain adequate provisions prohibiting emissions that 
will have certain adverse air quality effects in other states. On June 
28, 2010, the State of Idaho made a submittal to the Environmental 
Protection Agency (EPA) to address these requirements. The EPA is 
proposing to approve the submittal as meeting the requirement that each 
SIP contain adequate provisions to prohibit emissions that will 
contribute significantly to nonattainment or interfere with maintenance 
of the 2008 ozone National Ambient Air Quality Standard (NAAQS) in any 
other state.

DATES: Written comments must be received on or before November 30, 

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R10-
OAR-2015-0258, by any of the following methods:
     http://www.regulations.gov: Follow the on-line 
instructions for submitting comments.
     Email: [email protected]
     Mail: Kristin Hall, EPA Region 10, Office of Air, Waste 
and Toxics (AWT-150), 1200 Sixth Avenue, Suite 900, Seattle, WA 98101
     Hand Delivery/Courier: EPA Region 10 9th Floor Mailroom, 
1200 Sixth Avenue, Suite 900, Seattle, WA 98101. Attention: Kristin 
Hall, Office of Air, Waste and Toxics, AWT-150. Such deliveries are 
only accepted during normal hours of operation, and special 
arrangements should be made for deliveries of boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-R10-OAR-
2015-0258. The EPA's policy is that all comments received will be 
included in the public docket without change and may be made available 
online at http://www.regulations.gov, including any personal 
information provided, unless the comment includes information claimed 
to be Confidential Business Information (CBI) or other information 
whose disclosure is restricted by statute. Do not submit information 
that you consider to be CBI or otherwise protected through http://www.regulations.gov or email. The http://www.regulations.gov Web site 
is an ``anonymous access'' system, which means the EPA will not know 
your identity or contact information unless you provide it in the body 
of your comment. If you send an email comment directly to the EPA 
without going through http://www.regulations.gov your email address 
will be automatically captured and included as part of the comment that 
is placed in the public docket and made available on the Internet. If 
you submit

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an electronic comment, the EPA recommends that you include your name 
and other contact information in the body of your comment and with any 
disk or CD-ROM you submit. If the EPA cannot read your comment due to 
technical difficulties and cannot contact you for clarification, the 
EPA may not be able to consider your comment. Electronic files should 
avoid the use of special characters, any form of encryption, and be 
free of any defects or viruses.
    Docket: All documents in the docket are listed in the http://www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
the disclosure of which is restricted by statute. Certain other 
material, such as copyrighted material, is not placed on the Internet 
and will be publicly available only in hard copy. Publicly available 
docket materials are available either electronically in http://www.regulations.gov or in hard copy during normal business hours at the 
Office of Air, Waste and Toxics, EPA Region 10, 1200 Sixth Avenue, 
Seattle, WA 98101.

FOR FURTHER INFORMATION CONTACT: Kristin Hall at (206) 553-6357, 
[email protected], or the above EPA, Region 10 address.

SUPPLEMENTARY INFORMATION: Throughout this document wherever ``we,'' 
``us,'' or ``our'' is used, it is intended to refer to the EPA. 
Information is organized as follows:

Table of Contents

I. Background
II. State Submittal
III. EPA Evaluation
IV. Proposed Action
V. Statutory and Executive Order Reviews

I. Background

    On March 12, 2008, the EPA revised the levels of the primary and 
secondary 8-hour ozone standards from 0.08 parts per million (ppm) to 
0.075 ppm (73 FR 16436). The CAA requires states to submit, within 
three years after promulgation of a new or revised standard, SIPs 
meeting the applicable ``infrastructure'' elements of sections 
110(a)(1) and (2). One of these applicable infrastructure elements, CAA 
section 110(a)(2)(D)(i), requires SIPs to contain ``good neighbor'' 
provisions to prohibit certain adverse air quality effects on 
neighboring states due to interstate transport of pollution. There are 
four sub-elements within CAA section 110(a)(2)(D)(i). This action 
addresses the first two sub-elements of the good neighbor provisions, 
at CAA section 110(a)(2)(D)(i)(I). These sub-elements require that each 
SIP for a new or revised standard contain adequate provisions to 
prohibit any source or other type of emissions activity within the 
state from emitting air pollutants that will ``contribute significantly 
to nonattainment'' or ``interfere with maintenance'' of the applicable 
air quality standard in any other state. We note that the EPA has 
addressed the interstate transport requirements of CAA section 
110(a)(2)(D)(i)(I) for the eastern portion of the United States in 
several past regulatory actions.\1\ We most recently promulgated the 
Cross-State Air Pollution Rule (CSAPR), which addressed CAA section 
110(a)(2)(D)(i)(I) in the eastern portion of the United States.\2\ 
CSAPR addressed multiple national ambient air quality standards, but 
did not address the 2008 8-hour ozone standard.\3\

    \1\ NOX SIP Call, 63 FR 57371 (October 27, 1998); 
Clean Air Interstate Rule (CAIR), 70 FR 25172 (May 12, 2005); Cross-
State Air Pollution Rule (CSAPR), 76 FR 48208 (August 8, 2011).
    \2\ 76 FR 48208.
    \3\ CSAPR addressed the 1997 8-hour ozone, and the 1997 and 2006 
fine particulate matter NAAQS.

    In CSAPR, the EPA used detailed air quality analyses to determine 
whether an eastern state's contribution to downwind air quality 
problems was at or above specific thresholds. If a state's contribution 
did not exceed the specified air quality screening threshold, the state 
was not considered ``linked'' to identified downwind nonattainment and 
maintenance receptors and was therefore not considered to significantly 
contribute to or interfere with maintenance of the standard in those 
downwind areas. If a state exceeded that threshold, the state's 
emissions were further evaluated, taking into account both air quality 
and cost considerations, to determine what, if any, emissions 
reductions might be necessary. For the reasons stated below, we believe 
it is appropriate to use the same approach we used in CSAPR to 
establish an air quality screening threshold for the evaluation of 
interstate transport requirements for the 2008 ozone standard.
    In CSAPR, the EPA proposed an air quality screening threshold of 
one percent of the applicable NAAQS and requested comment on whether 
one percent was appropriate.\4\ The EPA evaluated the comments received 
and ultimately determined that one percent was an appropriately low 
threshold because there were important, even if relatively small, 
contributions to identified nonattainment and maintenance receptors 
from multiple upwind states. In response to commenters who advocated a 
higher or lower threshold than one percent, the EPA compiled the 
contribution modeling results for CSAPR to analyze the impact of 
different possible thresholds for the eastern United States. The EPA's 
analysis showed that the one-percent threshold captures a high 
percentage of the total pollution transport affecting downwind states, 
while the use of higher thresholds would exclude increasingly larger 
percentages of total transport. For example, at a five percent 
threshold, the majority of interstate pollution transport affecting 
downwind receptors would be excluded.\5\ In addition, the EPA 
determined that it was important to use a relatively lower one-percent 
threshold because there are adverse health impacts associated with 
ambient ozone even at low levels.\6\ The EPA also determined that a 
lower threshold such as 0.5 percent would result in modest increases in 
the overall percentages of fine particulate matter and ozone pollution 
transport captured relative to the amounts captured at the one-percent 
level. The EPA determined that a ``0.5 percent threshold could lead to 
emission reduction responsibilities in additional states that 
individually have a very small impact on those receptors--an indicator 
that emission controls in those states are likely to have a smaller air 
quality impact at the downwind receptor. We are not convinced that 
selecting a threshold below one percent is necessary or desirable.'' 

    \4\ CSAPR proposal, 75 FR 45210, 45237 (August 2, 2010).
    \5\ See also Air Quality Modeling Final Rule Technical Support 
Document, Appendix F; Analysis of Contribution Thresholds.
    \6\ CSAPR, 76 FR 48208, 48236-37 (August 8, 2011).
    \7\ Id.

    In the final CSAPR, the EPA determined that one percent was a 
reasonable choice considering the combined downwind impact of multiple 
upwind states in the eastern United States, the health effects of low 
levels of fine particulate matter and ozone pollution, and the EPA's 
previous use of a one-percent threshold in CAIR. The EPA used a single 
``bright line'' air quality threshold equal to one percent of the 1997 
8-hour ozone standard, or 0.08 ppm.\8\ The projected contribution from 
each state was averaged over multiple days with projected high modeled 
ozone, and then compared to the one-percent threshold. We concluded 
that this approach for setting and applying the air quality threshold 
for ozone was appropriate because it provided a robust metric, was 
consistent with the approach for fine particulate matter

[[Page 66864]]

used in CSAPR, and because it took into account, and would be 
applicable to, any future ozone standards below 0.08 ppm.\9\

    \8\ Id.
    \9\ Id.

II. State Submittal

    CAA sections 110(a)(1) and (2) and section 110(l) require that 
revisions to a SIP be adopted by the State after reasonable notice and 
public hearing. The EPA has promulgated specific procedural 
requirements for SIP revisions in 40 CFR part 51, subpart F. These 
requirements include publication of notices by prominent advertisement 
in the relevant geographic area, a public comment period of at least 30 
days, and an opportunity for a public hearing.
    On June 28, 2010, Idaho submitted a SIP to address the interstate 
transport requirements of CAA section 110(a)(2)(D)(i)(I) for the ozone 
NAAQS. The Idaho submittal included documentation of a public comment 
period from May 11, 2010 through June 10, 2010, and opportunity for 
public hearing. We find that the process followed by Idaho in adopting 
the submittal complies with the procedural requirements for SIP 
revisions under CAA section 110 and the EPA's implementing regulations.
    With respect to the requirements in CAA section 110(a)(2)(D)(i)(I), 
the Idaho submittal referred to applicable rules in the Idaho SIP, 
meteorological and technical characteristics of areas with ozone 
nonattainment problems in surrounding states, data on nitrogen oxides 
(NOX) and volatile organic compound (VOC) emissions from 
Idaho sources, satellite monitoring data, and the impacts of terrain 
and prevailing wind direction on the potential for transport of ozone 
precursors. The Idaho submittal concluded that given the relatively low 
amount of NOX emitted by Idaho sources, the general lack of 
substantial concentrations of VOCs in areas surrounding Idaho, the 
impacts of significant terrain features on the movement of pollutants, 
and technical information on the two areas in states bordering Idaho 
that are having ozone attainment and maintenance problems (Upper Green 
River Basin, Wyoming and Clark County, Nevada), it is reasonable to 
conclude that emissions of ozone precursors from Idaho sources will not 
significantly contribute to nonattainment or interfere with maintenance 
of the 2008 ozone NAAQS in any other state.
    The Idaho submittal provided further information to support this 
conclusion by citing major source permitting regulations approved into 
the Idaho SIP that require new sources and modifications to protect the 
ambient air quality standards, including the 2008 ozone NAAQS. With 
respect to existing sources, the Idaho submittal stated that stationary 
source operating rules in the Idaho SIP require an owner or operator to 
demonstrate that the source does not cause or contribute to a violation 
of any ambient air quality standard.

III. EPA Evaluation

    On August 4, 2015, the EPA issued a Notice of Data Availability 
(NODA) containing air quality modeling data that applies the CSAPR 
approach to contribution projections for the year 2017 for the 2008 8-
hour ozone NAAQS.\10\ The moderate area attainment date for the 2008 
ozone standard is July 11, 2018. In order to demonstrate attainment by 
this attainment deadline, states will use 2015 through 2017 ambient 
ozone data. Therefore, 2017 is an appropriate future year to model for 
the purpose of examining interstate transport for the 2008 ozone NAAQS. 
The EPA used photochemical air quality modeling to project ozone 
concentrations at air quality monitoring sites to 2017 and estimated 
state-by-state ozone contributions to those 2017 concentrations. This 
modeling used the Comprehensive Air Quality Model with Extensions (CAMx 
version 6.11) to model the 2011 base year, and the 2017 future base 
case emissions scenarios to identify projected nonattainment and 
maintenance sites with respect to the 2008 ozone NAAQS in 2017. The EPA 
used nationwide state-level ozone source apportionment modeling (CAMx 
Ozone Source Apportionment Technology/Anthropogenic Precursor 
Culpability Analysis technique) to quantify the contribution of 2017 
base case NOX and volatile VOC emissions from all sources in 
each state to the 2017 projected receptors. The air quality model runs 
were performed for a modeling domain that covers the 48 contiguous 
United States and adjacent portions of Canada and Mexico. The NODA and 
the supporting technical documents have been included in the docket for 
this action.

    \10\ See 80 FR 46271 (August 4, 2015) (Notice of Availability of 
the Environmental Protection Agency's Updated Ozone Transport 
Modeling Data for the 2008 Ozone National Ambient Air Quality 
Standard (NAAQS)).

    The modeling data released in the NODA on July 23, 2015, is the 
most up-to-date information the EPA has developed to inform our 
analysis of upwind state linkages to downwind air quality problems. For 
purposes of evaluating Idaho's interstate transport SIP submittal with 
respect to the 2008 8-hour ozone standard, the EPA is proposing that 
states whose contributions are less than one percent to downwind 
nonattainment and maintenance receptors are considered non-significant. 
The modeling indicates that Idaho's largest contribution to any 
projected downwind nonattainment site is 0.23 ppb and Idaho's largest 
contribution to any projected downwind maintenance-only site is 0.35 
ppb.\11\ These values are below the one percent screening threshold of 
0.75 ppb, and therefore there are no identified linkages between Idaho 
and 2017 downwind projected nonattainment and maintenance sites. Note 
that the EPA has not done an assessment to determine the applicability 
for the use of the one percent screening threshold for western states 
that contribute above the one percent threshold. There may be 
additional considerations that may impact regulatory decisions 
regarding ``potential'' linkages in the west identified by the 

    \11\ 80 FR 46271 at page 46276, Table 3.

IV. Proposed Action

    As discussed in Section II, Idaho concluded based on its own 
technical analysis that emissions from the State do not significantly 
contribute to nonattainment or interfere with maintenance of the 2008 
ozone standard in any other state. The EPA's modeling, discussed in 
Section III, confirms this finding. Based on the modeling data and the 
information and analysis provided in Idaho's June 28, 2010 submittal, 
we are proposing to approve the submittal for purposes of meeting the 
CAA section 110(a)(2)(D)(i)(I) requirements for the 2008 ozone 
standard. The EPA's modeling confirms the results of the State's 
analysis: Idaho does not significantly contribute to nonattainment or 
interfere with maintenance of the 2008 ozone standard in any other 

V. Statutory and Executive Order Reviews

    Under the CAA, the Administrator is required to approve a SIP 
submission that complies with the provisions of the CAA and applicable 
Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in 
reviewing SIP submissions, the EPA's role is to approve state choices, 
provided that they meet the criteria of the CAA. Accordingly, this 
action merely proposes to approve state law as meeting Federal 
requirements and does not impose additional requirements beyond those 
imposed by state law. For that reason, this action:

[[Page 66865]]

     Is not a ``significant regulatory action'' subject to 
review by the Office of Management and Budget under Executive Order 
12866 (58 FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 
     Does not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Is certified as not having a significant economic impact 
on a substantial number of small entities under the Regulatory 
Flexibility Act (5 U.S.C. 601 et seq.);
     Does not contain any unfunded mandate or significantly or 
uniquely affect small governments, as described in the Unfunded 
Mandates Reform Act of 1995 (Pub. L. 104-4);
     Does not have Federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Is not an economically significant regulatory action based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
     Is not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001);
     Is not subject to requirements of Section 12(d) of the 
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 
note) because it does not involve technical standards; and
     Does not provide the EPA with the discretionary authority 
to address, as appropriate, disproportionate human health or 
environmental effects, using practicable and legally permissible 
methods, under Executive Order 12898 (59 FR 7629, February 16, 1994).
    In addition, the SIP is not approved to apply on any Indian 
reservation land or in any other area where the EPA or an Indian tribe 
has demonstrated that a tribe has jurisdiction. In those areas of 
Indian country, the rule does not have tribal implications as specified 
by Executive Order 13175 (65 FR 67249, November 9, 2000), nor will it 
impose substantial direct costs on tribal governments or preempt tribal 

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Incorporation by 
reference, Intergovernmental relations, Ozone, Reporting and 
recordkeeping requirements.

    Authority: 42 U.S.C. 7401 et seq.

    Dated: October 15, 2015.
Dennis J. McLerran,
Regional Administrator, Region 10.
[FR Doc. 2015-27594 Filed 10-29-15; 8:45 am]