Document ID: EPA-R10-OAR-2022-0125-0001
Agency: epa
Document Type: Proposed Rule
Title: Air Quality State Implementation Plans; Approvals and Promulgations: Oregon; Oakridge Particulate Matter of 10 Microns or less Redesignation to Attainment and Maintenance Plan
Posted Date: 2022-05-09T04:00Z

[Federal Register Volume 87, Number 89 (Monday, May 9, 2022)]
[Proposed Rules]
[Pages 27540-27549]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-09254]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and 81

[EPA-R10-OAR-2022-0125; FRL-9489-01-R10]

Air Plan Approval; OR; Oakridge PM10 Redesignation to Attainment 
and Maintenance Plan

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) proposes to 
redesignate the Oakridge, Oregon nonattainment area (Oakridge NAA or 
Oakridge area) to attainment for the 1987 National Ambient Air Quality 
Standard for particulate matter of 10 microns or less (PM10 
NAAQS). EPA also proposes to approve the Oakridge PM10 
maintenance plan for the area demonstrating continued compliance with 
the PM10 NAAQS through with the Lane Regional Clean Air 
Agency (LRAPA), submitted to EPA on January 13, 2022, along with the 
redesignation request for inclusion into the Oregon State 
Implementation Plan (SIP). EPA also proposes to approve revisions to 
LRAPA's rules to reflect the redesignation. Additionally, EPA proposes 
to approve the PM10 motor vehicle emissions budgets included 
in the maintenance plan and inform the public that we are starting the 
adequacy process for the proposed motor vehicle emissions budgets, 
including a public comment period. Finally, EPA proposes to take final 
agency action on the wildfire exceptional event request submitted by 
ODEQ on July 22, 2021 and concurred on by EPA on April 1, 2022. EPA 
proposes these actions pursuant to the Clean Air Act (CAA or the Act).

DATES: Comments must be received on or before June 8, 2022.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R10-
OAR-2022-0125, at https://www.regulations.gov. Follow the online 
instructions for submitting comments. Once submitted, comments cannot 
be edited or removed from Regulations.gov. EPA may publish any comment 
received to its public docket. Do not electronically submit any 
information you consider to be Confidential Business Information (CBI) 
or other information the disclosure of which is restricted by statute. 
Multimedia submissions (audio, video, etc.) must be accompanied by a 
written comment. The written comment is considered the official comment 
and should include discussion of all points you wish to make. EPA will 
generally not consider comments or comment contents located outside of 
the primary submission (i.e., on the web, cloud, or other file sharing 
system). For additional submission methods, the full EPA public comment 
policy, information about CBI or multimedia submissions, and general 
guidance on making effective comments, please visit https://www.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Christi Duboiski (15-H13), EPA Region 
10, 1200 Sixth Avenue (Suite 155), Seattle WA, 98101, at (360) 753-
9081, or [email protected].

SUPPLEMENTARY INFORMATION: Throughout this document whenever ``we,'' or 
``our,'' is used, it refers to EPA.

Table of Contents

I. Background
II. Clean Air Act Requirements for Redesignation to Attainment
III. EPA's Analysis of Oregon's Submittal
    A. Attainment Determination
    B. Applicable Requirements Under Section 110 and Part D of the 
CAA
    1. CAA Section 110 General SIP Requirements
    2. Part D of Title I Requirements
    3. Fully Approved SIP Under CAA Section 110(k)
    C. Improvement in Air Quality Due to Permanent and Enforceable 
Measures
    D. Fully Approved Maintenance Plan
    1. Attainment Inventory
    2. Maintenance Demonstration
    3. Monitoring Network and Verification of Continued Attainment
    4. Contingency Plan

[[Page 27541]]

    E. Transportation Conformity and Motor Vehicle Emissions Budgets
    F. State Rule Changes To Reflect the Redesignation
IV. Proposed Action
V. Incorporation by Reference
VI. Statutory and Executive Orders Review

I. Background

    EPA revised the NAAQS for particulate matter on July 1, 1987, 
replacing standards for total suspended particulates, particulate less 
than 30 microns in diameter, with new standards applying only to 
PM10 (52 FR 24634). In 1987, EPA established two 
PM10 standards, an annual standard and a 24-hour standard. 
In 2006, the 24-hour PM10 standards were retained but the 
annual standards were revoked, effective December 18, 2006 (71 FR 
61144, October 17, 2006). On January 15, 2013 and December 18, 2020, 
EPA announced that it was again retaining the PM10 NAAQS as 
a 24-hour standard of 150 micrograms per cubic meter ([mu]g/m\3\) (78 
FR 3086 and 85 FR 82684). An area attains the 24-hour PM10 
standard when the expected number of days per calendar year with a 24-
hour concentration exceeding the standard (referred to as an 
exceedance), is equal to or less than one. Oregon's January 13, 2022, 
submittal of the Oakridge PM10 maintenance plan addresses 
the 1987 24-hour PM10 standard, as originally promulgated, 
and as reaffirmed on December 18, 2020.
    On December 21, 1993, EPA designated the Oakridge, Oregon urban 
growth boundary as nonattainment for PM10 and classified it 
as moderate under section 107(d)(3) of the CAA (58 FR 67334). The 
nonattainment area designation and classification became effective on 
January 20, 1994, with an attainment date for the area of December 31, 
2000.
    The nonattainment designation of the Oakridge NAA required Oregon 
to prepare and submit an attainment plan to meet statutory and 
regulatory requirements. On December 9, 1996, ODEQ submitted an 
attainment plan (1996 attainment plan) to EPA, and on March 15, 1999, 
EPA approved the attainment plan (64 FR 12751). The 1996 attainment 
plan consisted of an attainment year emission inventory, control 
measures that meet reasonably available control measures/technology 
(RACM/RACT), attainment demonstration, motor vehicle emission budgets 
(MVEBs), demonstration of reasonable further progress (RFP), 
quantitative milestones and contingency measures. In addition, on July 
26, 2001, EPA finalized a determination that the Oakridge NAA attained 
the PM10 NAAQS (Determination of Attainment) by the December 
31, 2000, attainment date (66 FR 38947).

II. Clean Air Act Requirements for Redesignation to Attainment

    The CAA provides the requirements for redesignating a nonattainment 
area to attainment. Specifically, section 107(d)(3)(E) of the CAA 
allows for redesignation provided that: (1) EPA determines that the 
area has attained the applicable NAAQS; (2) EPA has fully approved the 
applicable implementation plan for the area under section 110(k) of the 
CAA; (3) EPA determines that the improvement in air quality is due to 
permanent and enforceable reductions in emissions resulting from 
implementation of the applicable SIP and applicable Federal air 
pollutant control regulations and other permanent and enforceable 
reductions; (4) EPA has fully approved a maintenance plan for the area 
as meeting the requirements of section 175A of the CAA; and (5) the 
state has met all requirements applicable to the area under section 110 
and part D of the CAA. In this proposed action, EPA will review CAA 
section 107(d)(3)(E) requirements (2) and (5) together as part of our 
evaluation of Oregon's redesignation request.
    EPA has provided guidance on redesignation in the ``General 
Preamble,'' \1\ and has provided further guidance on processing 
redesignation requests in the following documents: (1) ``Procedures for 
Processing Requests to Redesignate Areas to Attainment,'' Memorandum 
from John Calcagni, Director, Air Quality Management Division, 
September 4, 1992 (hereafter the ``Calcagni Memo''); (2) ``State 
Implementation Plan (SIP) Actions Submitted in Response to Clean Air 
Act (CAA) Deadlines,'' Memorandum from John Calcagni, Director, Air 
Quality Management Division, October 28, 1992; and (3) ``Part D New 
Source Review (Part D NSR) Requirements for Areas Requesting 
Redesignation to Attainment,'' Memorandum from Mary D. Nichols, 
Assistant Administrator for Air and Radiation, October 14, 1994. These 
documents are included in the Docket for this proposed action.
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    \1\ See ``State Implementation Plans; General Preamble for the 
Implementation of Title I of the Clean Air Act Amendments of 1990,'' 
57 FR 13498, April 16, 1992.
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III. EPA's Analysis of Oregon's Submittal

    EPA proposes to redesignate the Oakridge NAA to attainment for the 
1987 24-hour PM10 NAAQS and proposes to approve into the 
Oregon SIP the associated Oakridge PM10 maintenance plan. 
EPA's proposed approval of the redesignation request and maintenance 
plan is based upon EPA's determination that the area continues to 
attain the 1987 24-hour PM10 NAAQS and that all other 
redesignation criteria have been met for the area. Sections III.A 
through D of this document describe how Oregon's January 13, 2022, 
submittal satisfies the requirements of section 107(d)(3)(E) of the CAA 
for the 1987 24-hour PM10 standard. In addition, EPA 
proposes to approve revisions to LRAPA's rules to reflect the 
redesignation of the Oakridge PM10 and fine particulate 
matter (PM2.5) nonattainment areas.\2\
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    \2\ We note that the January 13, 2022 submittal also includes 
the Oakridge PM2.5 redesignation and maintenance plan and 
revisions to the Lane County Code, which EPA will address in a 
separate action.
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    Oregon's submittal also addresses transportation conformity, MVEBs 
and emissions from wildfire-influenced PM10 concentrations 
recorded in the Oakridge NAA in 2020. EPA proposes to approve the MVEBs 
and proposes to approve the exclusion of data associated with the 
wildfire exceptional events that affected data in September of 2020 for 
purposes of showing continued attainment of the PM10 NAAQS.

A. Attainment Determination

    To redesignate an area from nonattainment to attainment, the CAA 
requires EPA to determine that the area has attained the applicable 
NAAQS (CAA section 107(d)(3)(E)(i)). An area has attained the 1987 24-
hour PM10 NAAQS if the average number of expected 
exceedances per year is less than or equal to one, when averaged over a 
three-year period.\3\ A state must demonstrate that an area has 
attained the PM10 NAAQS through submittal of ambient air 
quality data from an ambient air monitoring network for PM10 
to EPA's Air Quality System (AQS) (40 CFR 58.15 and 58.16(a)). Three 
years of representative data should be used (40 CFR part 50, Appendix 
K, 2.3(b)).
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    \3\ See 40 CFR part 50 and 40 CFR part 50, appendix K.
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The Exceptional Events Rule
    Congress has recognized that it may not be appropriate for EPA to 
use certain monitoring data collected by the ambient air quality 
monitoring network and maintained in EPA's AQS database \4\ in certain 
regulatory determinations. Thus, in 2005, Congress provided the 
statutory authority for the exclusion of data influenced by

[[Page 27542]]

``exceptional events'' meeting specific criteria by adding section 
319(b) to the CAA.\5\ To implement this 2005 CAA amendment, EPA 
promulgated the 2007 Exceptional Events Rule.\6\ The 2007 Exceptional 
Events Rule created a regulatory process codified at 40 CFR parts 50 
and 51 (Sec. Sec.  50.1, 50.14 and 51.930). These regulatory sections, 
which superseded EPA's previous guidance on handling data influenced by 
events, contain definitions, procedural requirements, requirements for 
air agency demonstrations, criteria for EPA's approval of the exclusion 
of event-affected air quality data from the data set used for 
regulatory decisions, and requirements for air agencies to take 
appropriate and reasonable actions to protect public health from 
exceedances or violations of the NAAQS. In 2016, EPA promulgated a 
comprehensive revision to the 2007 Exceptional Events Rule.\7\ Under 
the Exceptional Events Rule, for example, if a state demonstrates to 
EPA's satisfaction that emissions from a wildfire smoke event caused a 
specific air pollution concentration in excess of the PM10 
NAAQS at a particular air quality monitoring location and otherwise 
satisfies the requirements of 40 CFR 50.14, EPA must exclude that data 
from use in determinations of exceedances and violations.\8\
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    \4\ AQS is EPA's official repository of ambient air data.
    \5\ Under CAA section 319(b), an exceptional event means an 
event that (i) affects air quality; (ii) is not reasonably 
controllable or preventable; (iii) is an event caused by human 
activity that is unlikely to recur at a particular location or a 
natural event; and (iv) is determined by EPA under the process 
established in regulations promulgated by EPA in accordance with 
section 319(b)(2) to be an exceptional event. For the purposes of 
section 319(b), an exceptional event does not include (i) stagnation 
of air masses or meteorological inversions; (ii) a meteorological 
event involving high temperatures or lack of precipitation; or (iii) 
air pollution relating to source noncompliance.
    \6\ 72 FR 13560 (March 22, 2007).
    \7\ 81 FR 68216 (October 3, 2016). We refer herein to the 2016 
revision as the ``Exceptional Events Rule.''
    \8\ 40 CFR 50.14(b)(4).
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The Oakridge NAA Exceptional Event Demonstrations and Concurrences
    The CAA allows for the exclusion of air quality monitoring data 
from design value calculations when there are NAAQS exceedances caused 
by events, such as wildfires, that meet the criteria for an exceptional 
event identified in EPA's Exceptional Events Rule at 40 CFR 50.1, 50.14 
and 51.930. For the purposes of this proposed action, on July 22, 2021, 
ODEQ submitted an exceptional events demonstration for the purpose of 
showing that PM10 concentrations recorded at the Oakridge 
Willamette Center monitor from September 11, 2020 through September 16, 
2020 were influenced by wildfires. EPA concurred on this request on 
April 1, 2022.
    EPA found that Oregon's demonstration met the Exceptional Events 
Rule criteria and determined that the wildfire event had regulatory 
significance for purposes of calculating the area's most recent design 
value to demonstrate the area continues to attain the standard in order 
to redesignate the area to attainment for the PM10 NAAQS. As 
such, EPA proposes to take final regulatory action on the concurred 
dates, as detailed in the docket for this action, as exceptional events 
to be removed from the data set used for regulatory purposes. For this 
proposed action, EPA will rely on the calculated values that exclude 
the event-influenced data for the purpose of demonstrating continued 
attainment of the 1987 24-hour PM10 NAAQS. Further details 
on Oregon's analyses and EPA's concurrences can be found in the docket 
for this regulatory action.
    While EPA may agree with Oregon's request to exclude event 
influenced air quality monitoring data from regulatory decisions, these 
regulatory actions require EPA to provide an opportunity for public 
comment on the claimed exceptional event and all supporting data prior 
to EPA taking final agency action. This proposed action provides the 
public with an opportunity to comment on the claimed exceptional event, 
all supporting documents and EPA's concurrence with Oregon's request.
Evaluation of Current Attainment
    As noted previously, on July 26, 2001, EPA finalized a 
Determination of Attainment for the Oakridge NAA based upon quality-
assured and certified ambient air quality monitoring data for the 1998-
2000 design value period (66 FR 38947). There were no exceedances of 
the 24-hour PM10 standard during this period. Therefore, the 
expected exceedance rate was 0.0, which demonstrates attainment of the 
24-hour PM10 NAAQS.
    For this proposed action, EPA reviewed the most recent 
PM10 ambient air monitoring data in the Oakridge area for 
the monitoring design value period of 2018-2020. Consistent with the 
requirements at 40 CFR part 50, this ambient monitoring data in EPA's 
AQS has been quality-assured, quality-controlled and certified by ODEQ. 
The 24-hour PM10 design value for 2020 was 0.7, therefore, 
the average number of expected exceedances averaged over a three-year 
period is less than or equal to one.\9\ Thus, EPA concludes that the 
Oakridge area continues to demonstrate continued attainment of the 1987 
24-hour PM10 NAAQS during the three-year period ending on 
December 31, 2020.
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    \9\ As noted above, EPA excluded data for September 11, 2020 
through September 16, 2020 from this design value because the Agency 
determined concentrations recorded on those dates satisfied the 
requirements of the Exceptional Events Rule.
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B. Applicable Requirements Under Section 110 and Part D of the CAA

    Section 107(d)(3)(E)(ii) and (v) of the CAA require EPA to 
determine that the area has a fully approved applicable SIP under 
section 110(k) that meets all applicable requirements under section 110 
(general SIP requirements) and part D (SIP requirements for 
nonattainment areas) for the purposes of redesignation. We interpret 
this to mean that, for a redesignation request to be approved, the 
state must have met all requirements that applied to the subject area 
prior to, or at the time of, submitting a complete redesignation 
request. EPA may rely on prior SIP approvals in approving a 
redesignation request \10\ as well as any additional measure it may 
approve in conjunction with a redesignation action.
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    \10\ Calcagni Memo, 3; Wall v. EPA, 265 F.3d 426, 438 (6th Cir. 
2001); and Southwestern Pennsylvania Growth Alliance v. Browner, 144 
F.3d 984, 989-990 (6th Cir. 1998).
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1. CAA Section 110 General SIP Requirements
    Section 110(a)(2) of Title I of the CAA delineates the general 
requirements for a SIP. These requirements include, but are not limited 
to the following: (1) Submittal of a SIP that has been adopted by the 
state after reasonable public notice and hearing; (2) provisions for 
establishment and operation of appropriate procedures needed to monitor 
ambient air quality; (3) implementation of a source permit program; (4) 
provisions for the implementation of part C requirements (PSD); (5) 
provisions for the implementation of part D requirements for NSR permit 
programs; (6) provisions for air pollution modeling; and (7) provisions 
for public and local agency participation in planning and emission 
control rule development.\11\
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    \11\ See the General Preamble for further explanation of these 
requirements. 57 FR 13498 (April 16, 1992).
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    We note that SIPs must be fully approved only with respect to 
applicable requirements for purposes of redesignation in accordance 
with section 107(d)(3)(E)(ii). Similarly, EPA believes that the other 
CAA section 110(a)(2) (and part D) requirements that

[[Page 27543]]

are not connected with nonattainment plan submittals and not linked 
with an area's attainment status are not applicable requirements for 
purposes of redesignation because the area will still be subject to 
these requirements after it is redesignated. EPA considers the CAA 
section 110(a)(2) (and part D) requirements that relate to a particular 
nonattainment area's designation and classification as the relevant 
measures to evaluate in reviewing a redesignation request. This 
approach is consistent with EPA's existing policy on applicability of 
the conformity SIP requirement for redesignations.\12\
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    \12\ See 75 FR 36023, 36026 (June 24, 2010) and citations 
within.
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    EPA has reviewed the Oregon SIP and concludes that it meets the 
general SIP requirements under section 110(a)(2) of the CAA to the 
extent they are applicable for the purposes of redesignation.\13\ On 
several occasions, Oregon has submitted, and EPA has approved, 
provisions of Oregon's SIP as demonstrating compliance with CAA section 
110(a)(2) requirements.\14\ These requirements are, however, statewide 
requirements that are not linked to the PM10 nonattainment 
status of the Oakridge NAA. In addition, there are no outstanding or 
disapproved applicable SIP submittals with respect to the Oakridge 
portion of the SIP that would prevent redesignation of the Oakridge NAA 
for the PM10 NAAQS. Therefore, we conclude that ODEQ and 
LRAPA have met all general SIP requirements for the Oakridge NAA that 
are applicable for purposes of redesignating the area to attainment of 
the PM10 NAAQS.
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    \13\ The LRAPA portion of the federally-approved Oregon SIP can 
be viewed at https://www.epa.gov/sips-or/epa-approved-regulations-oregon-sip.
    \14\ See, e.g., 83 FR 24034 (May 24, 2019) and 84 FR 26347 (June 
6, 2019).
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2. Part D of Title I Requirements
    Before a PM10 nonattainment area may be redesignated to 
attainment, the state must have fulfilled the applicable requirements 
of part D of Title I of the CAA, which sets forth the basic 
nonattainment plan requirements applicable to all areas designated 
nonattainment. The general requirements are followed by a series of 
subparts specific to each pollutant. Subpart 1 of part D establishes 
the general requirements applicable to all NAAs, while subpart 4 of 
part D establishes specific requirements applicable to PM10 
NAAs. The General Preamble provides that the applicable requirements of 
subpart 1 (CAA section 172) are, in relevant part, 172(c)(3) (emissions 
inventory), 172(c)(5) (new source review permitting program), 172(c)(7) 
(the applicable provisions of section 110(a)(2)), and 172(c)(9) 
(contingency measures). It is also worth noting that we interpreted the 
requirements of section 172(c)(2) (RFP) and 172(c)(6) (other measures) 
as being irrelevant to a redesignation request because they only have 
meaning for an area that is not attaining the standard. See Calcagni 
Memo and the General Preamble, 57 FR 13530, 13564, dated April 16, 
1992. Finally, Oregon has not sought to exercise the options that would 
trigger CAA section 172(c)(8) (equivalent techniques). Thus, these 
provisions are also not relevant to this redesignation request.
    The requirements of CAA section 172(c) and 189(a) regarding 
attainment of the PM10 NAAQS, and the requirements of 
section 172(c) regarding RFP, imposition of RACM, the adoption of 
contingency measures, and the submittal of an emission inventory have 
been satisfied through our March 15, 1999, approval of the Oakridge 
PM10 SIP (64 FR 12751). Additionally, on July 26, 2001, EPA 
published a finding of attainment for the Oakridge PM10 area 
(66 FR 38947). EPA found that the Oakridge NAA attained the 24-hour 
PM10 NAAQS by the moderate PM10 attainment date 
of December 31, 2000.
    CAA section 172(c)(4) requires the identification and 
quantification of allowable emissions for major new and modified 
stationary sources in an area, and CAA section 172(c)(5) requires 
source permits for the construction and operation of new and modified 
major stationary sources anywhere in the nonattainment area. EPA first 
approved the requirements of the part D, subpart 1 NSR permit program 
for LRAPA on December 27, 2011 (76 FR 80747, 80748). Subsequently, 
LRAPA revised its rules to meet additional part D, subpart 4 NSR 
requirements promulgated by EPA (81 FR 58010, August 24, 2016) and to 
align with ODEQ's rules.\15\ EPA approved LRAPA's rules on October 5, 
2018 (83 FR 50274).
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    \15\ See 40 CFR 51.160, 51.161, 51.165, and 51.166. See also 
EPA's proposed approval of Oregon nonattainment NSR program (March 
22, 2017, 82 FR 14654, 14663) and EPA's final approval (October 11, 
2017, 82 FR 47122).
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    Once the Oakridge NAA is redesignated to attainment, the prevention 
of significant deterioration (PSD) requirements of part C of the Act 
will apply. LRAPA's PSD regulations are codified in Title 29 
(Designation of Air Quality Areas), Title 38 (New Source Review) and 
Title 50 (Ambient Air Standards and PSD Increments) in conjunction with 
other provisions including but not limited to LRAPA's rules in Titles 
12, 31, 34, 35, 40, and 42. We most recently approved revisions to 
LRAPA's PSD program on October 5, 2018 (83 FR 50274). EPA finds that 
LRAPA's PSD provisions meet all applicable Federal requirements for any 
area designated unclassifiable or attainment, and these provisions will 
become fully effective in the Oakridge area upon redesignation to 
attainment.
    CAA section 172(c)(7) requires the SIP to meet the applicable 
provisions of CAA section 110(a)(2). As noted above, we find that the 
Oregon SIP meets the CAA section 110(a)(2) applicable requirements. For 
purposes of redesignation to attainment for the 1987 24-hour 
PM10 NAAQS, EPA proposes to find that LRAPA has met all the 
applicable SIP requirements under part D of Title I of the CAA in 
accordance with section 107(d)(3)(E)(v) of the CAA.
3. Fully Approved SIP Under CAA Section 110(k)
    Section 110(k) of the CAA sets out provisions governing EPA's 
review of SIP submittals. In order for an area to qualify for 
redesignation, the SIP for the area must be fully approved under 
section 110(k) of the CAA. As discussed in Sections III.B.1 and III.B.2 
of this document, for purposes of redesignation to attainment for the 
1987 24-hour PM10 NAAQS, EPA has fully approved all 
applicable requirements of Oregon's SIP for the Oakridge area in 
accordance with CAA section 110(k). Therefore, the criterion for 
redesignation, set forth at CAA section 107(d)(3)(E)(ii), is satisfied.

C. Improvement in Air Quality Due to Permanent and Enforceable Measures

    In order to approve a redesignation to attainment, section 
107(d)(3)(E)(iii) of the CAA requires EPA to determine that the 
improvement in air quality is due to emissions reductions that are 
permanent and enforceable, and that the improvement is from the 
implementation of the applicable SIP, implementation of applicable 
Federal air pollution control regulations, and other permanent and 
enforceable reductions.
    The Oakridge 1996 attainment plan addressed attainment planning 
requirements for the Oakridge moderate NAA, including control measures 
to satisfy the RACM requirement and a demonstration that attainment of 
the PM10 NAAQS would be achieved by the required dates. The 
federally-approved 1996 attainment plan included woodstove change-outs, 
a voluntary residential woodsmoke curtailment program, commitment to 
reduce winter road sanding, and the paving of unpaved roads to reduce 
emissions of

[[Page 27544]]

PM10 in the Oakridge NAA. EPA's approval of this SIP made 
these control strategies federally enforceable.
    The historical PM10 air pollution problem in the 
Oakridge area has been emissions from residential wood combustion. 
Since 1993, as funding allowed, the Oakridge area has experienced 
emission reduction benefits from changing-out uncertified woodstoves 
for cleaner burning and more efficient home heating units. More 
recently, EPA approved the Oregon Heat Smart Program \16\ and the 
Oakridge City Air Pollution Control Ordinance 920 (Oakridge Ordinance 
920) \17\ into the Oregon SIP. Both prohibit the installation and ban 
the sale of non-EPA-certified devices in new or existing buildings. In 
addition to the initial woodstove change-outs provided for in the 1996 
attainment plan, these SIP strengthening control strategies provide for 
permanent and enforceable PM10 reductions in the Oakridge 
NAA.
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    \16\ A statewide mandate approved by EPA on October 11, 2017 (82 
FR 47122).
    \17\ See 83 FR 5537, February 8, 2018.
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    Since 1989, LRAPA, in cooperation with the City of Oakridge, has 
implemented a residential woodsmoke curtailment program in the Oakridge 
NAA. Oakridge Ordinance 815, State effective August 26, 1996 and 
federally-approved in the 1999 attainment plan, prohibited visible 
emission from a solid fuel burning device during a Red Advisory (when 
the PM10 levels are forecast by LRAPA to be greater than or 
equal to 120 [micro]g/m\3\) unless granted a sole source or economic 
need exemption. Oakridge Ordinance 815 is superseded by the federally-
approved Oakridge Ordinance 920, which is more protective of the 
PM10 NAAQS. In addition to the existing residential 
woodsmoke curtailment program, Oakridge Ordinance 920 provides further 
strengthening of the control measures while maintaining the integrity 
of the prior ordinance.
    Oakridge Ordinance 920 strengthens the SIP by prohibiting the 
burning of any fuel other than ``seasoned wood,'' which is defined as 
any species of wood that has been sufficiently dried to contain 20 
percent or less moisture by weight, and prohibiting the burning of 
specified materials such as plastic, rubber products, petroleum-treated 
materials and other materials which normally emit dense smoke, noxious 
odors, or hazardous air contaminants in a solid fuel burning device. 
EPA proposes to remove the City of Oakridge Ordinance 815 from the 
Oregon SIP because it is superseded by the federally-approved Oakridge 
Ordinance 920, which strengthens the PM10 SIP and ensures 
the woodstove curtailment program continues to be permanent and 
enforceable.
    The second largest source of PM10 emissions in the 
Oakridge NAA is road dust, of which winter road sanding and unpaved 
road dust are contributors. To reduce road sanding emissions the Oregon 
Department of Transportation (ODOT) has been using an anti-icing 
chemical, calcium magnesium acetate (CMA), instead of grit, within the 
City of Oakridge since 1995. ODOT continues to commit to using these 
chemicals into the future (See the September 20, 2021, letter from Jim 
Gamble, District 5 Manager, ODOT, included in the docket for this 
action). In addition, between 1991 and 1995 all of Oakridge's unpaved 
roads, approximately 2.5 miles, and numerous unpaved commercial 
driveways and parking lots were paved.\18\
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    \18\ See 64 FR 12751 (March 15, 1999).
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    Based on the foregoing evaluation of these control measures, EPA 
proposes to determine that the improvement in air quality is reasonably 
attributable to permanent and enforceable reductions in emissions 
resulting from implementation of the applicable implementation plan and 
other permanent and enforceable reductions. Therefore, the criterion 
for redesignation set forth at CAA section 107(d)(3)(E)(iii) is 
satisfied.

D. Fully Approved Maintenance Plan

    CAA section 107(d)(3)(E)(iv) requires that, for a nonattainment 
area to be redesignated to attainment, EPA must fully approve a 
maintenance plan for the area as meeting the requirements of CAA 
section 175A. The maintenance plan must demonstrate continued 
attainment of the relevant NAAQS in the area for at least 10 years 
after our approval of the redesignation. Eight years after 
redesignation, the state must submit a revised maintenance plan 
demonstrating attainment for the 10 years following the initial 10-year 
period. The maintenance plan must also contain a contingency plan to 
ensure prompt correction of any violation of the NAAQS that occurs 
after redesignation of the area. See CAA sections 175A(a), (b) and (d). 
The Calcagni Memo provides additional guidance on the content of a 
maintenance plan, stating that a maintenance plan should include the 
following elements: (1) An attainment emissions inventory; (2) a 
maintenance demonstration showing attainment for 10 years following 
redesignation; (3) a commitment to maintain and operate an appropriate 
air quality monitoring network; (4) verification of continued 
attainment; and (5) a contingency plan to prevent or correct future 
violations of the NAAQS. In this proposed action, EPA will review 
requirements (3) and (4) together as part of our evaluation of LRAPA's 
maintenance plan for the Oakridge area.
    In conjunction with Oregon's request to redesignate the Oakridge 
area to attainment, Oregon submitted a SIP revision to provide for 
maintenance of the 1987 24-hour PM10 NAAQS through 2035. EPA 
proposes to approve LRAPA's PM10 maintenance plan for the 
Oakridge area. The following paragraphs describe how each of the 
maintenance plan elements are addressed in the maintenance plan.
1. Attainment Inventory
    As discussed in the General Preamble (See 57 FR 13498, April 16, 
1992) and the Calcagni Memo, PM10 maintenance plans should 
include an attainment emission inventory to identify the level of 
emissions in the area sufficient to maintain the PM10 NAAQS. 
The maintenance plan attainment inventory should be consistent with 
EPA's emissions inventory requirements and most recent guidance on 
emissions inventories for nonattainment areas available at the time and 
should represent emissions during the time period associated with the 
monitoring data showing attainment.\19\ The inventory must also be 
comprehensive, including emissions from stationary point sources, area 
sources, mobile sources, and must be based on actual emissions during 
the appropriate season, if applicable.
---------------------------------------------------------------------------

    \19\ See Calcagni Memo at 8.
---------------------------------------------------------------------------

    The Oakridge PM10 maintenance plan includes a 2015 
PM10 attainment emission inventory (2015 attainment 
inventory) based on typical season and worst-case day actual emissions 
from all direct primary PM10 sources (point, area, on-road 
mobile and nonroad mobile sources.\20\ \21\ The year 2015 is

[[Page 27545]]

representative of the level of emissions during the time period when 
the Oakridge area's monitoring data shows attainment of the 1987 24-
hour PM10 NAAQS. The 2015 maintenance plan attainment 
inventory is based on emission reduction strategies that were 
implemented as of 2015. These are summarized in Table 1, along with 
future year projected emissions for a 2035 ``horizon year'' (a future 
year at least 10 years from the approval date of the maintenance plan), 
and two interim years of 2025 and 2030.
---------------------------------------------------------------------------

    \20\ ODEQ's PM10 emission inventory includes 
emissions within the larger Oakridge-Westfir PM2.5 
nonattainment area boundary (not the smaller Oakridge urban growth 
boundary). EPA believes this is appropriate in this instance (except 
for when calculating the motor vehicle emissions) because the 
Oakridge PM10 nonattainment area encompasses the vast 
majority of the population and activity within the Oakridge-Westfir 
PM2.5 NAA.
    \21\ PM10 precursor emissions should also be included 
depending upon the contribution of the secondarily-formed 
particulate matter to high ambient PM10 concentrations in 
the area. In this instance, an inventory of PM10 
precursor emissions is not required because PM10 
precursor controls were not relied upon to achieve attainment of the 
PM10 NAAQS in the Oakridge planning area (64 FR 12751, 
March 15, 1999), nor are they relied upon to demonstrate maintenance 
of the NAAQS. While not required, the maintenance plan includes an 
inventory of PM10 precursor emissions in Appendix II 
(``PM10 Emission Inventory for 2015 Base Year'').
---------------------------------------------------------------------------

    Oregon's 2015 attainment inventory relies on methods and 
assumptions presented in detail in Appendix II of the Oakridge 
PM10 maintenance plan (``Emision Inventory for 2015 Base 
Year''). The 2015 attainment inventory is based on typical season and 
worst-case day (episodic) emissions. The typical season day emissions 
represent an average daily emission value occurring from November 1 
through the end of February. This four-month time period is considered 
to be the particulate matter season and is when the PM10 
standard has historically been exceeded. EPA considers the preparation 
of the typical season day inventory and worst-case day inventory, as 
opposed to an annual average daily inventory, appropriate given that 
the elevated PM10 concentrations in Oakridge exhibit clear 
seasonal or episodic patterns. The worst-case day emissions represent a 
day during the PM season when emissions generating activity is at its 
highest due to meteorological factors like temperature. However, 
residential woodburning and other area source emissions on worst-case 
days are lower than on typical season days in the inventory due to 
woodburning curtailments and outdoor burning bans.
    Residential wood combustion emissions from woodstoves, fireplaces 
and pellet stoves continue to be the major source of PM10 
emissions for both typical season days and worst-case winter days 
contributing to exceedances of the NAAQS.

                          Table 1--Oakridge PM10 Maintenance Plan Emissions Inventories
                                               [In pounds per day]
----------------------------------------------------------------------------------------------------------------
                                                                                                    Difference
         Source category               2015        2025 Interim    2030 Interim        2035        from 2015 and
                                    Attainment                                      Maintenance        2035
----------------------------------------------------------------------------------------------------------------
                                              PM Typical Season Day
----------------------------------------------------------------------------------------------------------------
Point...........................             0.0             8.0             8.0             8.0             8.0
Area............................           444.8           364.2           364.0           363.5           -81.3
On-road.........................           142.1           131.0           133.2           132.8            -9.3
Nonroad.........................             2.9             2.9             2.9             2.9             0.0
                                 -------------------------------------------------------------------------------
    Total.......................           589.8           506.1           508.1           507.2           -82.6
----------------------------------------------------------------------------------------------------------------
                                                PM Worst-Case Day
----------------------------------------------------------------------------------------------------------------
Point...........................             0.0            13.7            13.7            13.7            13.7
Area............................           334.5           250.9           233.8           216.5          -118.0
On-road.........................           158.5           144.1           146.5           146.0           -12.5
Nonroad.........................             2.9             2.9             2.9             2.9               0
                                 -------------------------------------------------------------------------------
    Total.......................           495.9           411.6           396.9           379.1          -116.8
----------------------------------------------------------------------------------------------------------------

    Based on our review of the documentation provided in the 
maintenance plan, we propose to find that the 2015 direct 
PM10 attainment emission inventory is based on reasonable 
assumptions and methodologies, and that the inventory is comprehensive 
and based on the most accurate and current information available to 
LRAPA at the time it was developed. Based on our review of the 2015 
emissions inventory Oregon provided in its January 13, 2022 submittal, 
we propose to find that LRAPA prepared an adequate attainment inventory 
for the Oakridge area.\22\
---------------------------------------------------------------------------

    \22\ See ``Emissions Inventory Guidance for Implementation of 
Ozone and Particulate Matter National Ambient Air Quality Standards 
(NAAQS) and Regional Haze Regulations,'' May 2017, available at 
https://www.epa.gov/sites/default/files/2017-07/documents/ei_guidance_may_2017_final_rev.pdf.
---------------------------------------------------------------------------

2. Maintenance Demonstration
    CAA section 175A requires a state seeking redesignation to 
attainment to submit a SIP revision to provide for maintenance of the 
NAAQS for a period of at least 10 years following redesignation. A 
state can make this demonstration by either showing that future 
emissions of a pollutant or its precursors will not exceed the level of 
the attainment (base year) inventory, or by modeling to show that the 
future mix of sources and emission rates will not cause a violation of 
the NAAQS.\23\
---------------------------------------------------------------------------

    \23\ See Calcagni Memo, pages 9-10.
---------------------------------------------------------------------------

    In its maintenance demonstration for the Oakridge area, LRAPA 
elected to demonstrate maintenance of the PM10 NAAQS for at 
least 10 years following redesignation using the attainment year 
inventory method. LRAPA developed projected inventories, provided in 
Table 1 of this document, to show that the Oakridge area will remain in 
attainment through the year 2035. These projected inventories, covering 
interim years 2025 and 2030 and a horizon year of 2035, show that 
future emissions of direct PM10 throughout the nonattainment 
area will remain at or below the 2015 attainment emissions for the 1987 
24-hour PM10 NAAQS.
    The projected emissions inventories in the Oakridge PM10 
maintenance plan address four major source categories: Point, area, on-
road mobile and nonroad mobile. Oregon estimated future year emission 
inventories using the latest socioeconomic growth indictors and 
applying emissions reduction benefits from adopted control strategies 
when

[[Page 27546]]

appropriate. A detailed description of the 2015 attainment year 
inventory and the 2025, 2030 and 2035 projected inventories can be 
found in Appendix III of LRAPA's January 13, 2022, PM10 
maintenance plan submittal, which is in the docket for this action.
    As discussed in the Oakridge PM10 maintenance plan, 
direct PM10 emissions estimates for stationary point sources 
reflect actual emissions for both industrial point sources in Oakridge. 
The Oakridge Sand & Gravel ready-mix concrete plant and rock crusher 
did not operate in Oakridge in 2015, resulting in actual 2015 emissions 
that were zero. In addition, the ready-mix concrete plant air discharge 
permit was terminated on January 24, 2014, resulting in zero emissions 
in the 2015 and projected year emission inventories. Future year 
emissions were therefore based on the January 2011 PM10 
emissions at this source.
    Areawide sources occur over a wide geographic area with the most 
significant emissions resulting from residential wood combustion 
sources such as fireplaces, woodstoves and pellet stoves. These 
residential wood heating devices are commonly used to heat homes in 
Oakridge since natural gas is not available in this area. The permanent 
and enforceable residential wood combustion control strategies are 
discussed in Section III.C. of this document. The only other area 
source category with potentially significant emissions is outdoor 
burning, which is banned in Lane County from November-February. 
Emissions for these categories are derived using various surveys, 
emission factors and other methodologies.
    Emissions from on-road mobile sources (exhaust, brake wear and tire 
wear), which include passenger vehicles, buses, and trucks, were 
estimated using MOVES2014a. Traffic growth in Vehicle-Miles Traveled 
(VMT) was based on transportation modeling by the Lane Council of 
Governments (LCOG) and ODOT. LRAPA confirmed re-entrained road dust 
calculations for both paved and unpaved roads using AP-42 protocols. 
Federal control measures included in the MOVES2014a modeling are all 
Federal measures that affect the fleets and fuels used in future years 
once implemented by EPA.
    The nonroad emissions from railroads were calculated using the EPA 
NONROAD2008a emission protocol. The National Emissions Inventories 
(NEIs) for Lane County indicate a significant decrease in locomotive 
emissions from 2008 to 2014 (42.63 tons/year and 19.62 tons/year, 
respectively). The 2015 PM10 railroad emissions have been 
adjusted to reflect the locomotive emission reductions as seen in the 
2014 NEI data. Future year emissions are based on the adjusted 2014 and 
2017 NEI data. All other Oakridge nonroad mobile sources are 
categorized by LRAPA as insignificant during the PM10 winter 
season.
    EPA has reviewed the documentation provided by Oregon for 
developing the projected 2025, 2030 and 2035 emissions inventories for 
the Oakridge PM10 NAA. Based on our review, EPA finds that 
the projected inventories were developed using appropriate procedures, 
comprehensively address all source categories in the Oakridge area, and 
sufficiently account for PM10 projected actual emissions. 
These inventories indicate a decrease in PM10 emissions 
throughout the maintenance period. Therefore, EPA proposes to determine 
that the projected emissions inventories in the maintenance plan 
sufficiently demonstrate that the Oakridge PM10 area will 
continue to attain the 1987 24-hour PM10 standard throughout 
the maintenance period.
3. Monitoring Network and Verification of Continued Attainment
    Once a nonattainment area has been redesignated to attainment, the 
state must continue to operate an appropriate air quality monitoring 
network, in accordance with 40 CFR part 58, to verify the attainment 
status of the area. The maintenance plan should contain provisions for 
continued operation of air quality monitors that will provide such 
verification.
    LRAPA notes in the Oakridge PM10 maintenance plan that 
it currently operates a regulatory monitor (the Willamette Center 
monitor since 1989) in the Oakridge NAA. LRAPA commits to continue 
operating a regulatory monitoring network, in accordance with 40 CFR 
part 58 and the Oregon SIP through the year 2035 in order to verify 
continued attainment of the PM10 NAAQS and track the 
progress of the maintenance plan. LRAPA also states that it will 
continue to operate the PM10 monitoring network in 
accordance with the approved Annual Monitoring Network Plan (ANP). Any 
modification to the monitoring network will be done in consultation 
with ODEQ and with the approval of EPA Region 10 (See 40 CFR 58.14(b)). 
EPA will work with ODEQ and LRAPA each year through the air monitoring 
network review process to determine the adequacy of the monitoring 
network.\24\
---------------------------------------------------------------------------

    \24\ See EPA's February 22, 2022 approval of Oregon's 2021 
Annual Monitoring Network Plan, in the docket for this action.
---------------------------------------------------------------------------

    Oregon remains obligated to continue to quality-assure monitoring 
data and enter all data into AQS in accordance with Federal guidelines. 
LRAPA will review the air monitoring results each year to verify 
continued attainment. LRAPA will determine annually if exceptional 
events influenced the continued attainment of the 1987 24-hour 
PM10 NAAQS and need to be documented. If needed, ODEQ and 
LRAPA will coordinate and provide exceptional events documentation to 
EPA Region 10 for review.
    It should be noted that LRAPA included in the Oakridge maintenance 
plan a discussion on the use of PM2.5 monitoring as a 
surrogate for PM10 monitoring in the future. See Section 4.2 
of the Oakridge maintenance plan. Since any change to the monitoring 
network would occur in the future, EPA is not proposing to approve 
LRAPA discontinuing the PM10 monitor, nor is EPA making a 
determination whether the use of a PM2.5 surrogate monitor 
would be appropriate or consistent with 40 CFR part 58 requirements as 
part of this action.
    EPA proposes to determine that the Oakridge PM10 
maintenance plan contains adequate provisions for continued operation 
of an air quality monitoring network and a commitment to annually 
verify continued attainment of the 1987 24-hour PM10 NAAQS 
for the Oakridge area.
4. Contingency Plan
    CAA section 175A(d) requires that a maintenance plan also include 
contingency provisions, as necessary, to promptly correct any violation 
of the NAAQS that occurs after redesignation of the area to attainment. 
For the purposes of CAA section 175A, a state is not required to have 
fully adopted contingency measures that will take effect without 
further action by the state in order for the maintenance plan to be 
approved. However, the contingency plan is an enforceable part of the 
SIP and should ensure that contingency measures are adopted 
expeditiously once they are triggered. The maintenance plan should 
discuss the measures to be adopted and a schedule and procedure for 
adoption and implementation. The contingency plan must require that the 
state will implement all measures contained in the part D nonattainment 
plan for the area prior to redesignation. The state

[[Page 27547]]

should also identify the specific indicators, or triggers, which will 
be used to determine when the contingency plan will be implemented.\25\
---------------------------------------------------------------------------

    \25\ See Calcagni Memo at 12.
---------------------------------------------------------------------------

    The Oakridge PM10 maintenance plan outlines the 
procedures for the adoption and implementation of contingency measures 
to further reduce emissions should a violation of the PM10 
NAAQS or the 2006 24-hour PM2.5 NAAQS (35 [mu]g/m\3\) occur. 
It is expected that the PM2.5 NAAQS would be exceeded before 
the PM10 NAAQS, thus more quickly triggering the 
implementation of the contingency measures in the maintenance plan. If 
there is a violation of either standard, after consideration of any 
exceptional events, the following contingency strategies, or 
equivalent, will be implemented by LRAPA and the City of Oakridge:
     Stricter green-yellow-red advisory program,\26\ with more 
red advisory days each winter, by reducing the red advisory thresholds 
by 3 [mu]g/m\3\ PM10. This is projected to increase the 
average number of potential red advisory days by three to five 
additional days per year.
---------------------------------------------------------------------------

    \26\ LRAPA implements an advisory system that designates days as 
green, yellow, or red when 24-hour PM levels reach certain 
designated thresholds. During a red advisory day, LRAPA prohibits 
the use of any solid fuel space heating device that emits visible 
emissions into the air outside of the building housing the device 
unless a specific exemption has been granted.
---------------------------------------------------------------------------

     Prohibition of fireplace use on yellow advisory days (in 
addition to the existing prohibition on red advisory days).
    While these measures do not need to be fully adopted by LRAPA prior 
to the occurrence of a NAAQS violation, LRAPA commits to adopting and 
implementing the necessary contingency measures as expeditiously as 
possible, but not later than one year after a violation based on 
confirmed quality assured data.
    LRAPA will evaluate all appropriate data including air quality 
data, meteorological data, evaluation of wood smoke programs and 
information on unusual weather events (e.g., wildfires or winter power 
outages) and other data to determine the cause of the violation. LRAPA 
will perform this evaluation within three months of the determination 
of a violation. Where appropriate, LRAPA will follow EPA's exceptional 
events rules and guidance if it is determined that an exceptional event 
contributed to the violation.\27\
---------------------------------------------------------------------------

    \27\ Treatment of Data Influenced by Exceptional Events, October 
3, 2016, 81 FR 68216.
---------------------------------------------------------------------------

    Based on our analysis of Oregon's submittal, we propose to find 
that the contingency measure provisions provided in the Oakridge 
PM10 maintenance plan are sufficient and meet the 
requirements of CAA section 175A(d).

E. Transportation Conformity and Motor Vehicle Emissions Budgets

    Transportation conformity is required by CAA section 176(c). EPA's 
conformity rule at 40 CFR part 93, subpart A requires that 
transportation plans, programs, and projects conform to SIPs and 
establishes the criteria and procedures for determining whether or not 
they conform. Conformity to a SIP means that transportation activities 
will not produce new air quality violations, worsen existing 
violations, or delay timely attainment of the NAAQS. Thus, EPA's 
conformity rule requires a demonstration that emissions from a 
Metropolitan Planning Organization's (MPO's) Regional Transportation 
Plan and Transportation Improvement Program, involving Federal Highway 
Administration (FHWA) or Federal Transit Administration (FTA) funding 
or approval, are consistent with the MVEB(s) contained in a control 
strategy SIP revision or maintenance plan (40 CFR 93.101, 93.118, and 
93.124). A MVEB is the level of mobile source emissions of a pollutant 
relied upon in the attainment or maintenance demonstration to attain or 
maintain compliance with the NAAQS in the nonattainment or maintenance 
area.
    PM10 maintenance plan MVEBs are generally established 
for specific years and specific pollutants or precursors.\28\ The 
maintenance plan submittal should identify MVEBs for transportation 
related PM10 emissions (motor vehicle emissions from 
tailpipe, brake wear, tire wear and re-entrained road dust) in the last 
year of the maintenance period. Budgets may also be specified for 
additional years during the maintenance period.
---------------------------------------------------------------------------

    \28\ Transportation-related emissions of volatile organic 
compounds (VOCs) or nitrogen oxides (NOX) must also be 
specified in PM10 areas if EPA or the state find that 
transportation-related emissions of one or both of these precursors 
within the nonattainment area are a significant contributor to the 
PM10 nonattainment problem and has so notified the MPO 
and the U.S. Department of Transportation (DOT), or the applicable 
SIP revisions or SIP revision submittal establishes an approved or 
adequate budget for such emissions as part of the reasonable further 
progress, attainment or maintenance strategy. 40 CFR 
93.102(b)(2)(iii). Neither of these conditions apply to the Oakridge 
PM10 nonattainment area.
---------------------------------------------------------------------------

    It should be noted that Oakridge is considered an isolated rural 
nonattainment area within the meaning of 40 CFR 93.109(g), so 
transportation conformity determinations are only required when a non-
exempt Federal Highway Administration or Federal Transit Administration 
funded project is funded or approved.\29\
---------------------------------------------------------------------------

    \29\ See 40 CFR 93.109(g).
---------------------------------------------------------------------------

    With respect to previously established MVEBs, we note for the 1996 
attainment plan, Oregon had previously adopted PM10 MVEBs 
for 2003. These budgets were 178.8 pounds per day of direct 
PM10. This budget has continued to apply for conformity 
determinations since 2003. In addition, as determined in the 1996 
attainment plan approval, major sources of PM10 precursors 
do not contribute significantly to PM10 levels in excess of 
the PM10 NAAQs in the Oakridge NAA. Therefore, the Oakridge 
PM10 maintenance plan includes direct PM10 MVEBs 
that reflect the total on-road PM10 emissions for the 
attainment year (2015), and the projected PM10 emissions for 
two interim years (2025 and 2030) and the last year of the maintenance 
plan (2035). See Table 2, below.
    The MVEBs reflect the total on-road PM10 worst-case day 
emissions (a sum of primary exhaust, brake wear, tire wear and re-
entrained paved and unpaved road dust), plus a portion of the available 
safety margin to accommodate technical uncertainties due to model 
updates and inputs into the EPA MOVES model and travel forecasting 
models as well as potential changes to regional transportation plans. A 
safety margin is the amount by which the total projected 
PM10 emissions from all sources are less than the total 
emissions that would satisfy the NAAQS for the 2015 base year. With the 
safety margin applied to the future year MVEB, the budgets still 
demonstrate maintenance of the 1987 24-hour PM10 NAAQS.
    Oregon used the Motor Vehicle Emissions Simulator model, 
MOVES2014a, during the development of the maintenance plan and executed 
it with locally developed inputs representative of wintertime calendar 
year 2015 conditions and future projections in order to appropriately 
calculate the budgets. MOVES2014a was the accepted model when this work 
began. EPA recently released MOVES3, but since sufficient work had 
taken place on this SIP with MOVES2014a, we are accepting that mobile 
model in this submittal (86 FR 1106, 1108, January 7, 2021). Traffic 
growth in VMT for the Oakridge NAA is based on transportation modeling 
by Lane County, LCOG and ODOT. The mobile source emissions, in total, 
were modeled to steadily decrease between 2015 and 2035 as a result of 
cleaner vehicles and cleaner fuels. The MVEBs are based on the control 
measures in the

[[Page 27548]]

maintenance plan and consistent with maintaining the PM10 
NAAQS.
    The mobile source emissions budgets for the years 2015, 2025, 2030 
and 2035 are provided in Table 2 of this proposed action. According to 
EPA's conformity rule, the emissions budget acts as a ceiling on 
emissions in the year for which it is defined or until a SIP revision 
modifies the budget.\30\
---------------------------------------------------------------------------

    \30\ See 40 CFR 93.118.

                                  Table 2--PM10 MVEBs for the Oakridge PM10 NAA
----------------------------------------------------------------------------------------------------------------
                                                                             Year
       Motor vehicle emissions budgets       -------------------------------------------------------------------
                                                    2015             2025             2030             2035
----------------------------------------------------------------------------------------------------------------
PM10 (lbs/day)..............................           138.9            147.4            156.8            164.7
----------------------------------------------------------------------------------------------------------------

    For MVEBs to be approvable, they must meet, at a minimum, EPA's 
adequacy criteria (40 CFR 93.118(e)(4)). EPA's process for determining 
adequacy of a budget consists of three basic steps: (1) Notifying the 
public of a SIP submittal; (2) providing the public the opportunity to 
comment on the budget during a public comment period; and (3) making a 
finding of adequacy or inadequacy. The process for determining the 
adequacy of a submitted budget is codified at 40 CFR 93.118(f). EPA can 
notify the public by either posting an announcement that EPA has 
received SIP budgets on EPA's adequacy website (40 CFR 93.118(f)(1)), 
or via a Federal Register notice of proposed rulemaking when EPA 
reviews the adequacy of an implementation plan budget simultaneously 
with its review and action on the SIP itself (40 CFR 93.118(f)(2)).
    Today, we are notifying the public that EPA will be reviewing the 
adequacy of the 2015, 2025, 2030 and 2035 budgets in the Oakridge 
PM10 maintenance plan. The public has a 30-day comment 
period as described in the DATES section of this notice. After this 
comment period, EPA will indicate whether the budgets are adequate via 
the final rulemaking on this proposed action or on the adequacy 
website, according to 40 CFR 93.118(f)(2)(iii). The details of EPA's 
evaluation of the budget for compliance with the budget adequacy 
criteria of 40 CFR 93.118(e) are provided in a separate memorandum 
included with the docket for this rulemaking.\31\ As noted earlier, the 
public comment period for EPA's adequacy finding will be concurrent 
with the public comment period for this proposed action on the Oakridge 
PM10 maintenance plan.
---------------------------------------------------------------------------

    \31\ See EPA memorandum titled, ``EPA Region 10 Adequacy Review 
of Motor Vehicle Emissions Budgets in Oakridge PM10 
Maintenance Plan'', dated April 6, 2022.
---------------------------------------------------------------------------

    Based on the information presented in the Oakridge PM10 
maintenance plan and our adequacy review to date, we propose to find 
that Oregon has evaluated the appropriate pollutants and appropriately 
established MVEBs for direct PM10 emissions. EPA has 
reviewed the Oakridge PM10 maintenance plan's MVEBs and 
found them to be consistent with the control measures in the SIP and 
consistent with maintenance of the 1987 24-hour PM10 NAAQS 
within the Oakridge area through 2035. We propose to approve the MVEBs 
in the Oakridge PM10 maintenance plan as meeting the 
requirements of the CAA and EPA regulations.

F. State Rule Changes To Reflect the Redesignation

    Oregon adopted maintenance plans for both the Oakridge 
PM10 area and Oakridge PM2.5 area in the same 
state rulemaking package and submitted them as a single SIP submittal 
to EPA. This single submittal includes changes to LRAPA rules to 
reflect the anticipated redesignation of both areas. Today's action 
addresses the Oakridge PM10 area, and we are addressing the 
Oakridge PM2.5 area in a separate action. In today's action 
EPA is proposing to approve revisions to LRAPA's Title 29 Designation 
of Air Quality Areas, Section 29-0030(1) Designation of Nonattainment 
Areas and Section 29-0040(2)(b) Designation of Maintenance Areas. These 
revisions will remove the Oakridge PM10 nonattainment areas 
from the list of PM10 nonattainment areas and add them to 
the list of PM10 maintenance areas within the federally-
approved Oregon SIP.\32\
---------------------------------------------------------------------------

    \32\ On January 13, 2022, Oregon also submitted LRAPA Title 29 
Sections 0020, 0050-0090, 0300 and 0320. Oregon made no changes to 
these sections, except for the State effective date. EPA has 
reviewed these rules and approved them in a previous action (83 FR 
50274, March 23, 2018).
---------------------------------------------------------------------------

IV. Proposed Action

    EPA proposes to redesignate the Oakridge, Oregon PM10 
NAA, and proposes to approve the associated maintenance plan for the 
area. If this proposal is finalized, the designation status of the 
Oakridge, Oregon PM10 NAA, under 40 CFR part 81 will be 
revised to attainment upon the effective date of that final action.
    EPA proposes to approve and incorporate by reference into the 
Oregon SIP, the submitted revisions to LRAPA Title 29 Sections 29-
0030(1) and 29-0040(2)(b) state effective November 18, 2021. EPA also 
proposes to approve the State's request to remove from incorporation by 
reference City of Oakridge Ordinance 815, state effective August 15, 
1996.
    In addition, EPA proposes to take final agency action on Oregon's 
exceptional event demonstration for the Oakridge PM2.5 
monitor as discussed in this action.
    Finally, we propose to find that the Oakridge PM10 
maintenance plan's MVEBs meet applicable CAA requirements for 
maintenance plans and transportation conformity requirements. With this 
action, we are starting the adequacy process for these proposed MVEBs 
and opening a public comment period.
    We note that the January 13, 2022 submittal also includes the 
Oakridge PM2.5 redesignation and maintenance plan, revisions 
to the Lane County Code, and additional revisions to LRAPA's Title 29 
rules, which EPA will address in a separate action.

V. Incorporation by Reference

    In this document, EPA proposes to include in a final rule, 
regulatory text that includes incorporation by reference. In accordance 
with the requirements of 1 CFR 51.5, EPA proposes to incorporate by 
reference the provisions described in section IV of this preamble. EPA 
is also proposing to remove regulatory text that includes incorporation 
by reference. In accordance with requirements of 1 CFR 51.5, EPA 
proposes to remove the City of Oakridge Ordinance 815, state effective 
August 15, 1996, from the incorporation by reference as described in 
section IV of this preamble. EPA has made, and will continue to make, 
these documents generally available through

[[Page 27549]]

https://www.regulations.gov and at the EPA Region 10 Office (please 
contact the person identified in the FOR FURTHER INFORMATION CONTACT 
section of this preamble for more information).

VI. Statutory and Executive Orders Review

    Under the CAA, redesignation of an area to attainment and the 
accompanying approval of a maintenance plan under section 107(d)(3)(E) 
are actions that affect the status of a geographical area and do not 
impose any additional regulatory requirements on sources beyond those 
imposed by state law. A redesignation to attainment does not in and of 
itself create any new requirements, but rather results in the 
applicability of requirements contained in the CAA for areas that have 
been redesignated to attainment. Moreover, the Administrator is 
required to approve a SIP submittal 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 submittals, EPA's role is to 
approve State choices, provided that they meet the criteria of the CAA. 
Accordingly, this proposed action merely proposes to approve a State 
plan as meeting Federal requirements and does not impose additional 
requirements beyond those already imposed by State law. For that 
reason, this proposed action:
     Is not a ``significant regulatory action'' subject to 
review by the Office of Management and Budget under Executive Orders 
12866 (58 FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 
2011);
     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 CAA; and
     Does not provide 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 EPA or an Indian tribe has 
demonstrated that a tribe has jurisdiction. In those areas of Indian 
country, this rule does not have tribal implications as specified by 
Executive Order 13175 (65 FR 67249, November 9, 2000).

List of Subjects

40 CFR Part 52

    Environmental protection, Air pollution control, Carbon monoxide, 
Incorporation by reference, Intergovernmental relations, Lead, Nitrogen 
dioxide, Ozone, Particulate matter, Reporting and recordkeeping 
requirements, Sulfur oxides, Volatile organic compounds.

40 CFR Part 81

    Environmental protection, Air pollution control, National parks, 
Wilderness areas.

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

    Dated: April 25, 2022.
Michelle L. Pirzadeh,
Acting Regional Administrator, Region 10.
[FR Doc. 2022-09254 Filed 5-6-22; 8:45 am]
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