Document ID: EPA-R10-OAR-2011-0446-0010
Agency: epa
Document Type: Proposed Rule
Title: Air Quality State Implementation Plans; Approvals and Promulgations: Oregon; Interstate Transport of Fine Particulate Matter
Posted Date: 2014-05-14T04:00Z

[Federal Register Volume 79, Number 93 (Wednesday, May 14, 2014)]
[Proposed Rules]
[Pages 27528-27533]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-11075]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R10-OAR-2011-0446; FRL-9910-82-Region-10]

Approval and Promulgation of Implementation Plans; Oregon: 
Interstate Transport of Fine Particulate Matter

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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[[Page 27529]]

SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
approve a portion of the State Implementation Plan submittal from the 
State of Oregon to address Clean Air Act interstate transport 
requirements in section 110(a)(2)(D)(i)(I) for the 2006 24-hour fine 
particulate matter (PM2.5) National Ambient Air Quality 
Standards. The Clean Air Act requires that each State Implementation 
Plan contain adequate provisions prohibiting air emissions that will 
have certain adverse air quality effects in other states. The EPA is 
proposing to determine that Oregon's existing State Implementation Plan 
contains adequate provisions to ensure that air emissions in Oregon do 
not significantly contribute to nonattainment or interfere with 
maintenance of the 2006 24-hour PM2.5 National Ambient Air 
Quality Standard in any other state.

DATES: Written comments must be received on or before June 13, 2014.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R10-
OAR-2011-0446, by any of the following methods:
     www.regulations.gov: Follow the on-line instructions for 
submitting comments.
     Email: R10-Public_Comments@epa.gov.
     Mail: Dr. Karl Pepple, EPA Region 10, Office of Air, Waste 
and Toxics (AWT-107), 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: Dr. Karl 
Pepple, Office of Air, Waste and Toxics, AWT-107. 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-
2011-0446. 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 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 www.regulations.gov 
or email. The 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 
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 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 
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 
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: Dr. Karl Pepple at (206) 553-1778, 
pepple.karl@epa.gov, or the above EPA, Region 10 address.

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

Table of Contents

I. Background
    A. 2006 24-Hour PM2.5 NAAQS and Interstate Transport
    B. Rules Addressing Interstate Transport for the 2006 24-Hour 
PM2.5 NAAQS
    C. Guidance
II. The State Submittal
III. The EPA Evaluation
    A. Identification of Nonattainment and Maintenance Receptors
    B. Evaluation of Significant Contribution to Nonattainment
    C. Evaluation of Interference With Maintenance
IV. Proposed Action
V. Statutory and Executive Order Reviews

I. Background

A. 2006 24-Hour PM2.5 NAAQS and Interstate Transport

    On September 21, 2006, the EPA promulgated a final rule revising 
the 1997 24-hour primary and secondary National Ambient Air Quality 
Standards (NAAQS) for PM2.5 from 65 micrograms per cubic 
meter ([mu]g/m\3\) to 35 [mu]g/m\3\ (October 17, 2006, 71 FR 61144).
    The interstate transport provisions in Clean Air Act (CAA) section 
110(a)(2)(D)(i) (also called ``good neighbor'' provisions) require each 
state to submit a State Implementation Plan (SIP) that prohibits 
emissions that will have certain adverse air quality effects in other 
states. CAA section 110(a)(2)(D)(i) identifies four distinct elements 
related to the impacts of air pollutants transported across state 
lines. In this action, the EPA is addressing the first two elements of 
this section, specified at CAA section 110(a)(2)(D)(i)(I),\1\ for the 
2006 24-hour PM2.5 NAAQS.
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    \1\ This proposed action does not address the two elements of 
the interstate transport SIP provision in CAA section 
110(a)(2)(D)(i)(II) regarding interference with measures required to 
prevent significant deterioration of air quality or to protect 
visibility in another state. We previously published a notice 
approving the Oregon SIP for purposes of CAA section 
110(a)(2)(D)(I)(II) for the 2006 24-hour PM2.5 NAAQS on 
August 1, 2013 (78 FR46514).
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    The first element of CAA section 110(a)(2)(D)(i)(I) requires that 
each SIP for a new or revised NAAQS contain adequate measures to 
prohibit any source or other type of emissions activity within the 
state from emitting air pollutants that will ``contribute significantly 
to nonattainment'' of the NAAQS in another state. The second element of 
CAA section 110(a)(2)(D)(i)(I) requires that each SIP prohibit any 
source or other type of emissions activity in the state from emitting 
pollutants that will ``interfere with maintenance'' of the applicable 
NAAQS in any other state.

B. Rules Addressing Interstate Transport for the 2006 24-Hour 
PM2.5 NAAQS

    The EPA has previously addressed the requirements of CAA section 
110(a)(2)(D)(i)(I) in past regulatory actions.\2\ The EPA published the 
final Cross-State Air Pollution Rule (Transport Rule) to address the 
first two elements of CAA section 110(a)(2)(D)(i)(I) in the eastern 
portion of the United States with respect to the 2006 PM2.5 
NAAQS, the 1997 PM2.5 NAAQS, and the 1997 8-hour ozone NAAQS 
(August 8, 2011, 76 FR 48208). The Transport Rule was intended to 
replace the earlier Clean Air Interstate Rule (CAIR) which was 
judicially

[[Page 27530]]

remanded.\3\ See North Carolina v. EPA, 531 F.3d 896 (D.C. Cir. 2008). 
On August 21, 2012, the U.S. Court of Appeals for the D.C. Circuit 
issued a decision vacating the Transport Rule, see EME Homer City 
Generation, L.P. v. E.P.A., 696 F.3d 7 (D.C. Cir. 2012), and ordering 
the EPA to continue implementing CAIR in the interim. However, on April 
29, 2014, the U.S. Supreme Court reversed and remanded the D.C. 
Circuit's ruling and upheld the EPA's approach in the Transport Rule. 
EPA v. EME Homer City Generation, L.P., No. 12-1182, 572 U.S. ---- slip 
op. (2014).The State of Oregon was not covered by either CAIR or the 
Transport Rule, and the EPA made no determinations in either rule 
regarding whether emissions from sources in Oregon significantly 
contribute to nonattainment or interfere with maintenance of the 2006 
24-hour PM2.5 NAAQS in another state.
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    \2\ See NOX SIP Call, 63 FR 57371 (October 27, 1998); 
Clean Air Interstate Rule (CAIR), 70 FR 25172 (May 12, 2005); and 
Transport Rule or Cross-State Air Pollution Rule, 76 FR 48208 
(August 8, 2011).
    \3\ CAIR addressed the 1997 annual and 24-hour PM2.5 
NAAQS, and the 1997 8-hour ozone NAAQS. It did not address the 2006 
24-hour PM2.5 NAAQS. For more information on CAIR, see 
the July 30, 2012 proposal for Arizona regarding interstate 
transport for the 2006 PM2.5 NAAQS (77 FR 44551, 44552).
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C. Guidance

    On September 25, 2009, the EPA issued a guidance memorandum that 
addresses the requirements of CAA section 110(a)(2)(D)(i) for the 2006 
24-hour PM2.5 NAAQS (``2006 24-hour PM2.5 NAAQS 
Infrastructure Guidance'' or ``Guidance'').\4\ With respect to the 
requirement in CAA section 110(a)(2)(D)(i)(I) to prohibit emissions 
that would contribute significantly to nonattainment of the NAAQS in 
any other state, the 2006 24-hour PM2.5 NAAQS Infrastructure 
Guidance essentially reiterated the recommendations for western states 
made by the EPA in previous guidance addressing the CAA section 
110(a)(2)(D)(i) requirements for the 1997 8-hour Ozone and 1997 
PM2.5 NAAQS.\5\ The 2006 24-hour PM2.5 NAAQS 
Infrastructure Guidance advised states outside of the CAIR region to 
include in their CAA section 110(a)(2)(D)(i)(I) SIPs adequate technical 
analyses to support their conclusions regarding interstate pollution 
transport, e.g., information concerning emissions in the state, 
meteorological conditions in the state and in potentially impacted 
states, monitored ambient pollutant concentrations in the state and in 
potentially impacted states, distances to the nearest areas not 
attaining the NAAQS in other states, and air quality modeling.\6\ With 
respect to the requirement in CAA section 110(a)(2)(D)(i)(I) to 
prohibit emissions that would interfere with maintenance of the NAAQS 
in any other state, the Guidance stated that SIP submissions must 
address this independent requirement of the statute and provide 
technical information appropriate to support the state's conclusions, 
such as information concerning emissions in the state, meteorological 
conditions in the state and in potentially impacted states, monitored 
ambient concentrations in the state and in potentially impacted states, 
and air quality modeling. See footnotes 5 and 6. In this action, the 
EPA is proposing to use the conceptual approach to evaluating 
interstate pollution transport under CAA section 110(a)(2)(D)(i)(I) 
that the EPA explained in the 2006 24-hour PM2.5 NAAQS 
Infrastructure Guidance. For the 2006 24-hour PM2.5 NAAQS, 
the EPA believes that nonattainment and maintenance problems in the 
western United States are generally relatively local in nature with 
only limited impacts from interstate transport. The EPA believes that 
the CAA section 110(a)(2)(D)(i)(I) SIP submission from Oregon may be 
evaluated using a ``weight of the evidence'' approach that takes into 
account available relevant information. Such information may include, 
but is not limited to, the amount of emissions in the state relevant to 
the NAAQS in question, the meteorological conditions in the area, the 
distance from the state to the nearest monitors in other states that 
are appropriate receptors, or such other information as may be 
probative to consider whether sources in the state may contribute 
significantly to nonattainment or interfere with maintenance of the 
2006 24-hour PM2.5 NAAQS in other states. These submissions 
can rely on modeling when acceptable modeling technical analyses are 
available, but the EPA does not believe that modeling is necessarily 
required if other available information is sufficient to evaluate the 
presence or degree of interstate transport in a specific situation.\7\
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    \4\ See Memorandum from William T. Harnett entitled ``Guidance 
on SIP Elements Required Under Sections 110(a)(1) and (2) for the 
2006 24-Hour Fine Particle (PM2.5) National Ambient Air 
Quality Standards (NAAQS),'' September 25, 2009, available at http://www.epa.gov/ttn/caaa/t1/memoranda/20090925_harnett_pm25_sip_110a12.pdf.
    \5\ See Memorandum from William T. Harnett entitled ``Guidance 
for State Implementation Plan (SIP) Submission to Meet Current 
Outstanding Obligations Under Section 110(a)(2)(D)(i) for the 8-hour 
ozone and PM2.5 National Ambient Air Quality Standards,'' 
August 15, 2006, available at http://www.epa.gov/ttn/caaa/t1/memoranda/section110a2di_sip_guidance.pdf.
    \6\ The 2006 24-hour PM2.5 NAAQS Infrastructure 
Guidance states that EPA was working on a new rule to replace CAIR 
to address issues raised by the court in the North Carolina case and 
to provide guidance to states in addressing the requirements related 
to interstate transport in CAA section 110(a)(2)(D)(i)(I) for the 
2006 24-hour PM2.5 NAAQS. It also notes that states could 
not rely on the CAIR rule for section 110(a)(2)(D)(i)(I) submissions 
for the 2006 24-hour PM2.5 NAAQS because the CAIR rule 
did not address this NAAQS. See 2006 PM2.5 NAAQS 
Infrastructure Guidance at 4.
    \7\ See ``2006 24-hour PM2.5 NAAQS Infrastructure 
Guidance,'' issued September 25, 2009.
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II. The 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, the State of Oregon submitted a SIP revision to 
update the State's SIP for ozone and PM2.5. The State's SIP 
submittal cover letter indicated the SIP revision included the ``Oregon 
SIP Infrastructure for Addressing the Interstate Transport of Ozone and 
Fine Particulate Matter'' to address the interstate transport SIP 
requirements of CAA section 110(a)(2)(D)(i) for the 8-hour ozone and 
PM2.5 NAAQS (2010 Interstate Transport SIP). The State's 
June 28, 2010 submittal included public process documentation for the 
2010 Interstate Transport SIP, including documentation of a duly 
noticed public hearing held on December 22, 2009. The State 
subsequently notified the EPA that a clerical error was made and that 
the 2010 Interstate Transport SIP had not been attached to the June 28, 
2010, cover letter. The State transmitted the 2010 Interstate Transport 
SIP to the EPA on December 23, 2010. The State then transmitted a 
letter to the EPA on March 14, 2011, confirming that the 2010 
Interstate Transport SIP was submitted for purposes of meeting the 
requirements of CAA section 110(a)(2)(D)(i) for the 1997 ozone NAAQS, 
1997 PM2.5 NAAQS, 2006 24-hour PM2.5 NAAQS, and 
2008 ozone NAAQS.
    We find that the process followed by the State in adopting the 2010 
Interstate Transport SIP complies with the procedural requirements for 
SIP revisions under CAA section 110 and the EPA's implementing 
regulations.
    To address whether emissions from sources in Oregon significantly 
contribute to nonattainment of the 2006

[[Page 27531]]

24-hour PM2.5 NAAQS in another state, the State stated in 
the 2010 Interstate Transport SIP that meteorological and other 
characteristics of any areas designated nonattainment for the 2006 24-
hour PM2.5 NAAQS in the surrounding states of Washington, 
Idaho, Nevada, and California support a finding that emissions from 
Oregon sources do not significantly contribute to violations of the 
2006 24-hour PM2.5 NAAQS in other states. The State 
explained that the closest 2006 24-hour PM2.5 designated 
nonattainment areas in neighboring states are the Tacoma area (Pierce 
County) in Washington; the Chico area (portions of Butte County) in 
California; and the Cache Valley area in Southeast Idaho (portions of 
Cache County, Utah and Franklin County, Idaho). Oregon stated that the 
area of highest Oregon emission densities (Portland Metro area) is 
separated from these 2006 24-hour PM2.5 nonattainment areas 
by significant distances and major mountain ranges up to approximately 
7000 feet. The State identified one exception--the Portland, Oregon-
Vancouver, Washington metro area, which shares a common air shed 
between Oregon and Washington. Oregon noted however that both Portland, 
Oregon and Vancouver, Washington are in attainment with the 2006 24-
hour PM2.5 NAAQS.
    Additionally, the State described typical wind patterns during the 
winter when PM2.5 levels are the highest. It noted that the 
majority of wind speeds occur at less than eight miles per hour, and a 
significant portion of low winds occur at less than five miles per 
hour. The State explained that these low wind speeds and air stagnation 
conditions do not lend themselves to long distance air pollution 
transport. The State concluded that general meteorology supports the 
conclusion that high winter time PM2.5 levels in Pacific 
Northwest communities are typically dominated by local emission 
sources.
    Oregon's 2010 Interstate Transport SIP also pointed to its CAA 
section 110 infrastructure SIP to demonstrate that Oregon Department of 
Environmental Quality (ODEQ) has the ability to participate as needed 
in future studies on regional air pollution issues, can collaborate 
with other states if air quality concerns are identified that require a 
case-specific evaluation of interstate transport, and has the legal 
mechanism to take action as needed to reduce emissions to help attain 
compliance with Federal NAAQS. Oregon stated that that high 
PM2.5 levels that threaten the NAAQS are investigated as 
needed to identify contributing sources, including any potential role 
of interstate transport.
    Finally, the State explained that it had consulted with air 
agencies in Washington, Idaho, Nevada, and California and other 
agencies to evaluate case-specific air quality problems that may 
involve regional transport of air pollution. These staff-level 
communications indicated no impacts on PM2.5 concentrations 
in other states caused by transport from Oregon.
    Based on the information provided in its 2010 Interstate Transport 
SIP, the State concluded that emissions from air pollution sources in 
Oregon do not significantly contribute to nonattainment of the 2006 24-
hour PM2.5 NAAQS in other states.

III. The EPA Evaluation

    To determine whether the CAA section 110(a)(2)(D)(i)(I) requirement 
is satisfied, the EPA must determine whether a state's emissions 
contribute significantly to nonattainment or interfere with maintenance 
of the NAAQS in other states. If this factual finding is in the 
negative, then CAA section 110(a)(2)(D)(i)(I) does not require any 
changes to a state's SIP. Consistent with the EPA's approach in the 
1998 NOX SIP Call, the 2005 CAIR, and the 2011 Transport 
Rule, the EPA is evaluating these impacts with respect to specific 
monitors identified as having nonattainment and/or maintenance 
problems, which we refer to as ``receptors.'' See footnote 2.
    This proposed approval addresses the requirements of CAA section 
110(a)(2)(D)(i)(I) for the 2006 24-hour PM2.5 NAAQS in 
several ways. The EPA notes that no single piece of information is by 
itself dispositive of the issue. Instead, the total weight of all the 
evidence taken together is used to evaluate significant contributions 
to nonattainment or interference with maintenance of the 2006 24-hour 
PM2.5 NAAQS in another state. Our proposed approval takes 
into account Oregon's 2010 Interstate Transport SIP which explains that 
meteorological and other characteristics in Oregon and in the 
surrounding areas reduce the likelihood that emissions from sources in 
Oregon contribute significantly to nonattainment or interfere with 
maintenance of the 2006 24-hour PM2.5 NAAQS in any downwind 
state. In addition, we are supplementing the evaluation of the State's 
submittal with a review of the monitors in other states that are 
appropriate ``nonattainment receptors'' or ``maintenance receptors'' 
and additional technical information to consider whether sources in 
Oregon contribute significantly to nonattainment or interfere with 
maintenance of the 2006 24-hour PM2.5 NAAQS in other states.
    Our Technical Support Document (TSD) contains a more detailed 
evaluation and is available in the public docket for this rulemaking, 
which may be accessed online at www.regulations.gov, docket number EPA-
R10-OAR-2011-0446. Below is a summary of our analysis.

A. Identification of Nonattainment and Maintenance Receptors

    The EPA evaluated data from existing monitors over three 
overlapping three-year periods (i.e., 2008-2010, 2009-2011, and 2010-
2012) to determine which areas were violating the 2006 24-hour 
PM2.5 NAAQS and which areas might have difficulty 
maintaining attainment. If a monitoring site measured a violation of 
the 2006 24-hour PM2.5 NAAQS during the most recent three-
year period (2010-2012), then this monitor location was evaluated for 
purposes of the significant contribution to nonattainment element of 
CAA section 110(a)(2)(D)(i)(I). If, on the other hand, a monitoring 
site shows attainment of the 2006 24-hour PM2.5 NAAQS during 
the most recent three-year period (2010-2012) but a violation in at 
least one of the previous two three-year periods (2008-2010 or 2009-
2011), then this monitor location was evaluated for purposes of the 
interference with maintenance element of the statute.
    The State of Oregon was not covered by the original modeling 
analyses conducted for the CAIR and the Transport Rule. The approach 
described above is similar to the approach utilized by the EPA in 
promulgating the CAIR and the Transport Rule. By this method, the EPA 
has identified those areas with monitors to be considered 
``nonattainment receptors'' or ``maintenance receptors'' for evaluating 
whether the emissions from sources in another state could significantly 
contribute to nonattainment in, or interfere with maintenance in, that 
particular area.

B. Evaluation of Significant Contribution to Nonattainment

    The EPA reviewed Oregon's 2010 Interstate Transport SIP and 
additional technical information to evaluate the potential for 
emissions from sources in Oregon to contribute significantly to 
nonattainment of the 2006 24-hour PM2.5 NAAQS at specified 
monitoring

[[Page 27532]]

sites in the western United States.\8\ The EPA first identified as 
``nonattainment receptors'' all monitoring sites in the western states 
that had recorded PM2.5 design values above the level of the 
2006 24-hour PM2.5 NAAQS (35 [mu]g/m\3\) during the years 
2010-2012.\9\ See Section III of the TSD for more a more detailed 
description of the EPA's methodology for selection of nonattainment 
receptors. All of the nonattainment receptors identified in western 
states are in California, Idaho, Oregon, and Utah. Because geographic 
distance is a relevant factor in the assessment of potential pollution 
transport, the EPA focused its review on information related to 
potential transport of PM2.5 pollution from Oregon to 
nonattainment receptors in the states bordering Oregon: Idaho and 
California.\10\ \11\ As detailed in the TSD, the EPA believes that the 
following factors support a finding that emissions from Oregon do not 
significantly contribute to nonattainment of the 2006 24-hour 
PM2.5 NAAQS in these states: (1) Technical information 
indicating that elevated PM2.5 levels at nonattainment 
receptors are predominantly caused by local emission sources and (2) 
air quality data indicating that regional background levels of 
PM2.5 are generally low during the time periods of elevated 
PM2.5 at these receptors. In addition, as detailed in the 
TSD with respect to California, technical information indicating that 
the dominant air flows across California are from the west to the east 
additionally supports a finding that emissions from Oregon do not 
significantly contribute to nonattainment of the 2006 24-hour 
PM2.5 NAAQS in California.
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    \8\ EPA has also considered potential PM2.5 transport 
from Oregon to the nearest nonattainment and maintenance receptors 
located in the eastern, midwestern, and southern states covered by 
the Transport Rule and believes it is reasonable to conclude that, 
given the significant distance from Oregon to the nearest such 
receptor (in Illinois) and the relatively insignificant amount of 
emissions from Oregon that could potentially be transported such a 
distance, emissions from Oregon sources do not significantly 
contribute to nonattainment or interfere with maintenance of the 
2006 24-hour PM2.5 NAAQS at this location. These same 
factors also support a finding that emissions from Oregon sources 
neither contribute significantly to nonattainment nor interfere with 
maintenance of the 2006 24-hour PM2.5 NAAQS at any 
location further east. See TSD at Section II.C.
    \9\ Because CAIR did not cover states in the western United 
States, these data are not significantly impacted by the remanded 
CAIR at this time and thus could be considered in this analysis.
    \10\ As this analysis is focused on interstate transport, the 
EPA did not evaluate the impact of Oregon emissions onnonattainment 
receptors within Oregon.
    \11\ Washington and Nevada have no nonattainment receptors. See 
TSD at Table III.A.1.
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    The EPA also evaluated potential PM2.5 transport to 
nonattainment receptors in the more distant western state of Utah. The 
EPA believes that the following factors support a finding that 
emissions from Oregon do not significantly contribute to nonattainment 
of the 2006 24-hour PM2.5 NAAQS in Utah: (1) The significant 
distance from Oregon to the nonattainment receptors in Utah, (2) 
technical information indicating that elevated PM2.5 levels 
at nonattainment receptors in Utah are predominantly caused by local 
emission sources, and (3) air quality data indicating that regional 
background levels of PM2.5 are generally low during the time 
periods of elevated PM2.5 at Utah receptors.
    Based on this evaluation of Oregon's 2010 Interstate Transport SIP 
and additional technical information, the EPA proposes to conclude that 
emissions from sources in Oregon do not significantly contribute to 
nonattainment of the 2006 24-hour PM2.5 NAAQS in any other 
state.

C. Evaluation of Interference With Maintenance

    The EPA reviewed Oregon's 2010 Interstate Transport SIP and 
additional technical information to evaluate the potential for Oregon 
emissions to interfere with maintenance of the 2006 24-hour 
PM2.5 NAAQS at specified monitoring sites in the western 
United States. The EPA first identified as ``maintenance receptors'' 
all monitoring sites in the western states that had recorded 
PM2.5 design values above the level of the 2006 24-hour 
PM2.5 NAAQS (35 [mu]g/m\3\) during the 2008-2010 and/or 
2009-2011 periods but below this standard during the 2010-2012 period. 
See section III of the TSD for more information regarding the EPA's 
methodology for selection of maintenance receptors. All of the 
maintenance receptors in the western states are located in California, 
Montana, Nevada, Oregon, Utah, and Washington. The EPA focused its 
evaluation of the potential for transport of Oregon emissions to the 
maintenance receptors located in three states bordering Oregon: 
California, Nevada, and Washington.\12 13\ As detailed in the TSD, the 
EPA believes that the following factors support a finding that 
emissions from sources in Oregon do not interfere with maintenance of 
the 2006 24-hour PM2.5 NAAQS in these border states: (1) 
Technical information indicating that elevated 24-hour PM2.5 
levels at these maintenance receptors are predominantly caused by local 
emission sources, and (2) air quality data indicating that regional 
background levels of PM2.5 are generally low during the time 
periods of elevated 24-hour PM2.5 at these receptors. In 
addition, with respect to California, technical information indicating 
that elevated 24-hour PM2.5 levels at the maintenance 
receptors are predominantly caused by local emission sources and that 
the dominant air flows across California are from the west to the east 
additionally supports a finding that emissions from sources in Oregon 
do not interfere with maintenance of the 2006 24-hour PM2.5 
NAAQS in California.
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    \12\ As this analysis is focused on interstate transport, the 
EPA did not evaluate the impact of Oregon emissions on maintenance 
receptors within Oregon.
    \13\ Idaho has no maintenance receptors. See TSD at Table 
III.A.1.
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    The EPA also evaluated the potential for transport of Oregon 
emissions to maintenance receptors in the more distant states of 
Montana and Utah. As detailed in the TSD, the EPA believes that the 
following factors support a finding that emissions from sources in 
Oregon do not interfere with maintenance of the 2006 24-hour 
PM2.5 NAAQS in these more distant states: (1) The 
significant distance from the Oregon to the maintenance receptors in 
these states, (2) technical information indicating that elevated 24-
hour PM2.5 levels at these maintenance receptors are 
predominantly caused by local emission sources, and (3) air quality 
data indicating that regional background levels of PM2.5 are 
generally low during the time periods of elevated 24-hour 
PM2.5 at these receptors.
    Based on this evaluation of Oregon's 2010 Interstate Transport SIP 
and additional technical information, the EPA proposes to conclude that 
emissions from sources in Oregon do not interfere with maintenance of 
the 2006 24-hour PM2.5 NAAQS in any other state.

IV. Proposed Action

    The EPA is proposing to approve the portion of the SIP revision 
submitted by the State of Oregon on June 28, 2010 that addresses the 
interstate transport requirements of CAA section 110(a)(2)(D)(i)(I) for 
the 2006 24-hour PM2.5 NAAQS. The EPA is proposing to 
determine that Oregon's existing State Implementation Plan contains 
adequate provisions to ensure that air emissions in Oregon do not 
significantly contribute to nonattainment or interfere with maintenance 
of the 2006 24-hour PM2.5 National Ambient Air Quality 
Standard in any other state. This action

[[Page 27533]]

is being taken under section 110 of the CAA.

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 Act 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:
     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);
     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 application of those requirements would be inconsistent 
with the Clean Air Act; 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, this proposed rule does not have tribal implications 
as specified by Executive Order 13175 (65 FR 67249, November 9, 2000), 
because the SIP is not approved to apply in Indian country located in 
the state, and the EPA notes that it will not impose substantial direct 
costs on tribal governments or preempt tribal law.

List of Subjects in 40 CFR Part 52

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

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

    Dated: April 10, 2014.
Michelle L. Pirzadeh,
Acting Regional Administrator, Region 10.
[FR Doc. 2014-11075 Filed 5-13-14; 8:45 am]
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