[Federal Register Volume 90, Number 54 (Friday, March 21, 2025)]
[Proposed Rules]
[Pages 13316-13322]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-04791]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R09-OAR-2025-0070; FRL-12637-02-R9]


Determination of Attainment by the Attainment Date; 2008 8-Hour 
Ozone Standards; California; Sacramento Metro Area

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed determination.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
determine that the Sacramento Metro, California area attained the 2008 
8-hour ozone national ambient air quality standards (NAAQS) by its 
December 31, 2024 attainment date. This proposed determination is based 
on quality-assured and certified ambient air quality monitoring data 
from 2022 through 2024. If we finalize this determination as proposed, 
the requirement for the State to have contingency measures for 
reasonable further progress (RFP) and attainment for the 2008 ozone 
NAAQS will no longer apply for this area. We are taking comments on 
this proposal and plan to follow with a final action. Elsewhere in this 
Federal Register, we are making an interim final determination that 
will stay and defer the imposition of Clean Air Act (CAA or ``Act'') 
sanctions associated with a disapproval action related to the 
contingency measures requirement for this area.

DATES: Comments must be received on or before April 21, 2025.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R09-
OAR-2025-0070 at https://www.regulations.gov. For comments submitted at 
Regulations.gov, follow the online instructions for submitting

[[Page 13317]]

comments. Once submitted, comments cannot be edited or removed from 
Regulations.gov. The EPA may publish any comment received to its public 
docket. Do not submit electronically any information you consider to be 
Confidential Business Information (CBI) or other information whose 
disclosure 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. The 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, please contact the person identified in 
the FOR FURTHER INFORMATION CONTACT section. For 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. If you need assistance in a 
language other than English or if you are a person with a disability 
who needs a reasonable accommodation at no cost to you, please contact 
the person identified in the FOR FURTHER INFORMATION CONTACT section.

FOR FURTHER INFORMATION CONTACT: Laura Lawrence, EPA Region IX, 75 
Hawthorne St., San Francisco, CA 94105; phone: (415) 972-3407; email: 
[email protected].

SUPPLEMENTARY INFORMATION: Throughout this document, ``we,'' ``us,'' 
and ``our'' refer to the EPA.

Table of Contents

I. Background
    A. Regulatory Context
    B. The Sacramento Metro Area
II. EPA Analysis
    A. Applicable Statutory and Regulatory Provisions
    B. Determination of Attainment or Failure To Attain
    C. Monitoring Network Considerations
    D. Data Considerations
    E. Effects of This Proposed Determination
III. Action Summary
IV. Statutory and Executive Order Reviews

I. Background

A. Regulatory Context

    The CAA requires the EPA to establish primary and secondary NAAQS 
for certain pervasive pollutants that ``may reasonably be anticipated 
to endanger public health and welfare.'' \1\ The primary NAAQS is 
designed to protect public health with an adequate margin of safety, 
and the secondary NAAQS is designed to protect public welfare and the 
environment. The EPA has set standards for six common air pollutants, 
referred to as criteria pollutants, including ozone. These standards 
represent the air quality levels an area must meet to comply with the 
CAA.
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    \1\ CAA section 108(a).
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    Ground-level ozone pollution is formed from the reaction of 
volatile organic compounds (VOC) and oxides of nitrogen 
(NOX) in the presence of sunlight.\2\ These two pollutants, 
referred to as ozone precursors, are emitted by many types of sources, 
including on- and off-road motor vehicles and engines, power plants and 
industrial facilities, and smaller area sources such as lawn and garden 
equipment and paints.
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    \2\ The State of California refers to reactive organic gases 
(ROG) rather than VOC in some of its ozone related SIP submissions. 
As a practical matter, ROG and VOC refer to the same set of chemical 
constituents, and for the sake of simplicity, we refer to this set 
of gases as VOC in this determination notice.
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    Scientific evidence indicates that adverse public health effects 
occur following exposure to ozone, particularly in children and adults 
with lung disease. Breathing air containing ozone can reduce lung 
function and inflame airways, which can increase respiratory symptoms 
and aggravate asthma or other lung diseases.\3\
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    \3\ EPA, Health Effects of Ozone Pollution, available at https://www.epa.gov/ground-levelozone-pollution/health-effects-ozone-pollution.
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    In March 2008, the EPA strengthened the ozone NAAQS, establishing 
primary and secondary 8-hour ozone standards at a level of 0.075 parts 
per million (ppm) (``2008 ozone NAAQS'').\4\ The numerical level of the 
NAAQS had previously been set at 0.08 ppm.\5\ Section 107(d) of the CAA 
requires the EPA to designate an area ``nonattainment'' if it is 
violating the standards or if it has sources contributing to a 
violation of the standards in a nearby area. For ozone standards, the 
EPA classifies nonattainment areas as ``Marginal,'' ``Moderate,'' 
``Serious,'' ``Severe,'' or ``Extreme,'' depending upon ambient air 
monitoring values at the time of designation.\6\ An ozone nonattainment 
area with a higher classification is subject to more stringent CAA 
planning and control requirements than lower classification areas, but 
the state is provided more time to attain the NAAQS.\7\
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    \4\ 73 FR 16436 (March 27, 2008).
    \5\ In October 2015, the EPA further strengthened the primary 
and secondary eight-hour ozone NAAQS from 0.075 ppm to 0.070 ppm. 80 
FR 65291 (October 26, 2015). This action relates only to the 2008 
ozone NAAQS.
    \6\ See CAA section 181(a)(1).
    \7\ See, generally, subpart 2 of part D of title I of the CAA.
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    An area is considered to have attained the 2008 ozone standard if 
there are no violations of the standard, as determined in accordance 
with 40 CFR 50.15, based on three consecutive years of complete, 
quality-assured, and certified monitoring data. A violation of the 
NAAQS occurs when the ambient ozone air quality monitoring data show 
that the 3-year average of the annual fourth-highest daily maximum 8-
hour average ozone concentrations at an ozone monitor is greater than 
0.075 ppm.\8\
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    \8\ 40 CFR 50.15 and 40 CFR part 50, Appendix P.
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B. The Sacramento Metro Area

    The EPA designated the Sacramento Metro area as nonattainment for 
the 2008 ozone NAAQS on May 21, 2012, and classified the area as 
``Severe-15.'' \9\ The area's applicable attainment date for the 2008 
ozone NAAQS is December 31, 2024.\10\
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    \9\ 77 FR 30088 (May 21, 2012).
    \10\ See 85 FR 68509, 68510 (October 29, 2020).
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    The Sacramento Metro area consists of Sacramento and Yolo counties 
and portions of El Dorado, Placer, Solano and Sutter counties, and is 
under the jurisdiction of the California Air Resources Board (CARB) and 
the following regional air pollution control districts: the El Dorado 
County Air Quality Management District (EDCAQMD), the Feather River Air 
Quality Management District (FRAQMD), the Placer County Air Pollution 
Control District (PCAPCD), the Sacramento Metropolitan Air Quality 
Management District (SMAQMD), and the Yolo-Solano Air Quality 
Management District (YSAQMD) (collectively, ``Districts'').\11\ The 
nonattainment area also includes Tribal lands under the jurisdiction of 
the Shingle Springs Band of Miwok Indians, Shingle Springs Rancheria 
(Verona Track), California; the United Auburn Indian Community of the 
Auburn Rancheria of California, and the Yocha Dehe Wintun Nation, 
California.
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    \11\ For a precise description of the geographic boundaries of 
the Sacramento Metro Area for the 2008 ozone NAAQS, refer to 40 CFR 
81.305. Specifically included portions are the eastern portion of 
Solano County, the western portions of Placer and El Dorado counties 
outside of the Lake Tahoe Basin, and the southern portion of Sutter 
County.
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    CARB is the state agency responsible for the adoption and 
submission to the EPA of California State Implementation Plan (SIP) 
submissions. Under California law, air districts in California are 
generally responsible for the

[[Page 13318]]

development of regional air quality plans. For the Sacramento Metro 
area, the Districts develop and adopt air quality management plans to 
address CAA planning requirements applicable to the region. The 
Districts then submit such plans to CARB for adoption and submission to 
the EPA as proposed revisions to the California SIP. In general, Tribes 
are not required to submit Tribal Implementation Plan (TIP) 
submissions.\12\
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    \12\ See 40 CFR 49.4(a) (specifying that Tribes are not subject 
to implementation plan submittal deadlines).
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    The EPA approved the State's attainment and reasonable further 
progress (RFP) demonstrations and other required planning elements for 
the 2008 ozone NAAQS for the Sacramento Metro area on October 22, 
2021.\13\ However, we deferred action on the requirement for 
contingency measures that would be implemented in the event the area 
fails to attain (``attainment contingency measures'') or fails to meet 
RFP milestones (``RFP contingency measures''). We subsequently 
disapproved the area's contingency measures submittal on June 15, 
2023.\14\ This disapproval started sanctions clocks pursuant to section 
179 of the CAA and 40 CFR 52.31, by which the offset sanction in CAA 
section 179(b)(2) would be imposed after 18 months of the effective 
date of the disapproval and the highway funding sanction in CAA section 
179(b)(1) would be imposed six months after the offset sanction was 
imposed, as well as the two-year clock for the EPA to promulgate a 
Federal Implementation Plan (FIP) under CAA section 110(c). California 
submitted contingency measures for the 2008 ozone NAAQS in the 
Sacramento Metro area on December 23, 2024.\15\ The EPA has not yet 
taken action on this submittal; the offset sanction has been in effect 
for the area since January 17, 2025, and the highway funding sanction 
is set to come into effect on July 17, 2025. We are concurrently making 
an interim final determination to stay the offset sanction and to defer 
the highway funding sanction associated with our 2023 disapproval of 
the contingency measures submittal. As described in Section II.E of 
this document, a final determination of attainment by the attainment 
date would permanently stop the sanctions and FIP clocks associated 
with this previous disapproval action, and would permanently lift the 
offset sanction that has been in place.
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    \13\ 86 FR 58581.
    \14\ 88 FR 39179.
    \15\ CARB adopted the contingency measures as a SIP revision on 
December 20, 2024, through CARB Executive Order S-24-016, and 
submitted the SIP revision to the EPA electronically on December 23, 
2024, as an attachment to a letter dated December 20, 2024, from 
Steven S. Cliff, Ph.D., Executive Officer, CARB to Martha Guzman, 
Regional Administrator, EPA Region IX. The State's submittal 
addresses contingency measures requirements for the 2008 and 2015 
ozone NAAQS.
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II. EPA Analysis

A. Applicable Statutory and Regulatory Provisions

    The EPA is required under CAA 181(b)(2) to determine whether an 
ozone nonattainment area has attained the ozone standards by the area's 
attainment date. A determination of whether an area's air quality meets 
the 2008 ozone NAAQS is generally based on three years of complete, 
quality-assured, and certified air quality monitoring data gathered at 
established State and Local Air Monitoring Stations (``SLAMS'') in the 
area and entered into the EPA's Air Quality System (AQS) database.\16\ 
Data from ambient air monitors operated by state/local agencies in 
compliance with EPA monitoring requirements must be submitted to the 
AQS database. Monitoring agencies annually certify that these data are 
accurate to the best of their knowledge. Accordingly, the EPA relies 
primarily on data in its AQS database when determining the attainment 
status of an area.\17\ All data are reviewed to determine the area's 
air quality status in accordance with 40 CFR part 50, Appendix P.
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    \16\ Generally, a ``complete'' data set for determining 
attainment of ozone NAAQS is one that includes three years of data. 
There are less stringent data requirements for showing that a 
monitor has failed an attainment test and thus has recorded a 
violation of the standard.
    \17\ 40 CFR 50.15; 40 CFR part 50, Appendix P; 40 CFR part 53; 
40 CFR part 58, Appendices A, C, D, and E.
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    Under EPA regulations at 40 CFR 50.15, an area attains the 2008 
ozone NAAQS when the 3-year average of the annual fourth-highest daily 
maximum 8-hour average ozone monitor concentrations is less than or 
equal to 0.075 ppm. This 3-year average is referred to as the ``design 
value.'' When the design value is greater than 0.075 ppm at any monitor 
within the area, then the area is violating the NAAQS.\18\ The data 
completeness requirement is met when the average percent of days with 
valid ambient monitoring data is greater than or equal to 90 percent 
and no single year has less than 75 percent data completeness, as 
determined under Appendix P of 40 CFR part 50.\19\
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    \18\ The data handling convention in 40 CFR part 50, Appendix P 
dictates that concentrations shall be reported in ppm to the third 
decimal place, with additional digits to the right being truncated. 
Thus, a computed 3-year average ozone concentration of 0.076 ppm is 
greater than 0.075 ppm and would exceed the standard, but a design 
value of 0.0759 is truncated to 0.075 and attains the 2008 ozone 
NAAQS.
    \19\ 40 CFR part 50, Appendix P, section 2.3(b).
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B. Determination of Attainment or Failure To Attain

    The EPA is proposing to determine that the Sacramento Metro area 
attained the 2008 ozone NAAQS by its applicable attainment date; that 
is, that the average of the annual fourth-highest daily maximum 8-hour 
average ozone concentrations was at or below 0.075 ppm in the three 
years leading up to the applicable attainment date. This proposed 
determination is based on three years of quality-assured and certified 
ambient air quality monitoring data in AQS for the 2022-2024 monitoring 
period.
    The EPA's proposed determination of attainment is based upon data 
that have been collected and quality assured in accordance with 40 CFR 
part 58 and recorded in the EPA's AQS database.\20\ As discussed in 
Section II.D of this document, ambient air quality monitoring data for 
the 3-year period preceding the attainment date (i.e., 2022-2024 for 
the 2008 ozone NAAQS for the Sacramento Metro area, based on the 
applicable attainment date of December 31, 2024) meet the data 
completeness requirements in 40 CFR part 50, Appendix P.
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    \20\ The EPA maintains the AQS, a database that contains ambient 
air pollution data collected by the EPA, state, local, and tribal 
air pollution control agencies. The AQS also contains meteorological 
data, descriptive information about each monitoring station 
(including its geographic location and its operator) and data 
quality assurance/quality control information. The AQS data is used 
to (1) assess air quality, (2) assist in attainment/non-attainment 
designations, (3) evaluate SIPs for nonattainment areas, (4) perform 
modeling for permit review analysis, and (5) prepare reports for 
Congress as mandated by the CAA. Access is through the website at 
https://www.epa.gov/aqs.
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C. Monitoring Network Considerations

    Section 110(a)(2)(B)(i) of the CAA requires states to establish and 
operate air monitoring networks to compile data on ambient air quality 
for all criteria pollutants. The ambient air monitoring network in the 
Sacramento Metro area includes air monitoring stations that are managed 
and operated by CARB, PCAPCD, SMAQMD, and YSAQMD. Although portions of 
the EDCAQMD and FRAQMD are within the nonattainment area, neither 
district operates SLAMS ozone monitors in the Sacramento Metro area. 
CARB operates SLAMS ozone monitors within the portion of EDCAQMD that 
is within the nonattainment area, and there are no ozone monitors 
within the portion of the FRAQMD that lies within the Sacramento Metro 
nonattainment

[[Page 13319]]

area.\21\ CARB and SMAQMD submit annual network plans to the EPA.\22\ 
These plans document the status of CARB and the Districts' air 
monitoring networks, as required under 40 CFR 58.10. The EPA reviews 
these annual network plans for compliance with specific requirements in 
40 CFR part 58. With respect to ozone, we have found that the annual 
network plans submitted by CARB and SMAQMD meet the minimum monitoring 
requirements of 40 CFR part 58.\23\
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    \21\ The FRAQMD maintains jurisdiction in both Sutter County and 
Yuba County. A portion of Sutter County is included in the 
Sacramento Metro nonattainment area, and none of Yuba County is 
included in the nonattainment area.
    \22\ CARB's annual network plan includes the PCAPCD and YSAQMD 
ambient air monitoring networks. SMAQMD submits its own annual 
network plan.
    \23\ We have included copies of CARB and SMAQMD's annual network 
plans for 2022-2024 in the docket for this action, along with our 
reviews of these plans and our associated transmittal 
correspondence.
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    Finally, the EPA conducts regular Technical Systems Audits (TSAs) 
to review and inspect state and local ambient air monitoring programs 
to assess compliance with applicable regulations concerning the 
collection, analysis, validation, and reporting of ambient air quality 
data. CARB is a Primary Quality Assurance Organization (PQAO) in 
California that is responsible for overseeing the quality of data 
collected by local air monitoring organizations, which includes the 
Districts. For the purposes of this determination, we reviewed the 
findings from the EPA's most recent TSA of CARB's ambient air 
monitoring program.\24\ The results of this TSA found that the CARB 
PQAO quality system was functioning well and produced ozone data 
suitable for use in regulatory decision-making. Therefore, the results 
of the TSA do not preclude the EPA from determining that the Sacramento 
Metro area has attained the 2008 ozone NAAQS.
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    \24\ See letter from Matthew Lakin, Director, Air and Radiation 
Division, U.S. EPA Region IX, to Edie Chang, Deputy Executive 
Officer, CARB, dated March 14, 2024, and enclosure titled 
``Technical Systems Audit of the Ambient Air Monitoring Program: 
CARB, December 2021-August 2022.''
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D. Data Considerations

    In accordance with 40 CFR 58.15, SMAQMD and CARB certify annually 
that the previous year's ambient concentration and quality assurance 
data are completely submitted to AQS and that the ambient concentration 
data are accurate, taking into consideration the quality assurance 
findings.\25\ SMAQMD certifies data from its monitoring network, and 
CARB certifies data for the CARB network as well as the PCAPCD and 
YSAQMD networks. There were 16 ozone monitoring sites located 
throughout the Sacramento Metro area in calendar years 2022 through 
2024: three within El Dorado County, four within Placer County, six 
within Sacramento County, one within Solano County, and two within Yolo 
County.\26\ Table 1 of this document summarizes the ozone monitoring 
data from the various monitoring sites in the Sacramento Metro area by 
showing the annual 4th highest daily maximum concentrations and design 
values over the 2022-2024 period. The data summarized in table 1 of 
this document are considered complete for the purposes of determining 
if the standard is met.\27\
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    \25\ We have included SMAQMD's and CARB's annual data 
certifications for 2022, 2023, and 2024 in the docket for this 
action.
    \26\ See page 9 of SMAQMD's 2024 Air Monitoring Network Plan 
(July 15, 2024) for a map illustrating the locations of the air 
monitoring sites in the SMAQMD.
    \27\ The criteria for data completeness are met at most of the 
ozone monitors over the 2022-2024 period but were not met for the 
ozone monitors at the Echo Summit, North Highlands--Blackfoot Way, 
and Sloughhouse monitoring sites.

Table 1--Sacramento Metro Area Fourth High 8-Hour Ozone Average Concentrations and Design Values (ppm) for 2022-
                                                      2024
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                                                             4th Highest daily maximum
          AQS site ID               Site name    ------------------------------------------------  Design value
                                                       2022            2023            2024         (2022-2024)
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                                                EL DORADO COUNTY
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06-017-0012...................  Echo Summit.....           0.064           0.065          \a\ NA     \b\ Invalid
06-017-0020...................  Cool............           0.074           0.072           0.072           0.072
06-017-2004...................  Placerville--Can           0.066           0.067           0.067           0.066
                                 al Street.
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                                                  PLACER COUNTY
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06-061-0003...................  Auburn--Atwood..           0.075           0.064           0.079           0.072
06-061-0004...................  Colfax--City               0.070           0.067           0.067           0.068
                                 Hall.
06-061-0006...................  Roseville--N               0.070           0.077           0.077           0.074
                                 Sunrise Ave.
06-061-2003...................  Lincoln--2885              0.066           0.060           0.063           0.063
                                 Moore Road.
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                                                SACRAMENTO COUNTY
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06-067-0002...................  North Highlands--         \a\ NA          \a\ NA          \a\ NA     \c\ Invalid
                                 Blackfoot Way.
06-067-0006...................  Sacramento Del             0.070           0.077           0.080           0.075
                                 Paso Manor.
06-067-0010...................  Sacramento--T              0.065           0.066           0.069           0.066
                                 Street.
06-067-0011...................  Elk Grove--                0.058           0.050           0.048           0.052
                                 Bruceville.
06-067-0012...................  Folsom..........           0.070           0.071           0.065           0.068
06-067-5003...................  Sloughhouse.....           0.074          \a\ NA          \a\ NA     \d\ Invalid
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                                                  SOLANO COUNTY
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06-095-3003...................  Vacaville.......           0.063           0.061           0.058           0.060
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                                                   YOLO COUNTY
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06-113-0004...................  Davis--UCD                 0.059           0.065           0.063           0.062
                                 Campus.
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06-113-1003...................  Woodland--Gibson           0.066           0.062           0.064           0.064
                                 Road.
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\a\ The required annual 75 percent completeness criterion was not met, therefore the annual 4th highest daily
  maximum values were not provided.
\b\ The design value for the Echo Summit site is invalid due to missing data for the month of April in 2022 and
  2024 as well as null coded data in AQS with site computer/data logger down from April through May of 2024.
\c\ The design value for the North Highlands--Blackfoot Way site is invalid due to missing data from August 2022
  through December 2024. SMAQMD lost the lease to the North Highlands--Blackfoot Way monitoring site and were
  forced to shut down the monitor on August 1, 2022. SMAQMD is looking to secure a new location for the site.
\d\ The Sloughhouse design value is invalid due to null coded data in AQS with poor quality assurance results
  from July 2023 through April 2024.
Invalid design values and annual 4th highest daily maximum values can be found in the ``SFNA O3 Design Value
  Report 2008-2024.pdf''.
Source: EPA, AQS Design Value (AMP480), Report Request ID: 2260106, February 6, 2025.

    Consistent with the requirements contained in 40 CFR part 50, the 
EPA has reviewed the quality-assured and certified ozone ambient air 
monitoring data for completeness. The EPA reviewed the data as recorded 
in AQS for the applicable monitoring period, collected at the 
monitoring sites in the Sacramento Metro area, and has determined that 
the data are generally complete, with the exceptions of the Echo 
Summit, North Highlands--Blackfoot Way, and Sloughhouse monitoring 
sites. These exceptions are described below:
     The Echo Summit monitoring site, which typically operates 
seasonally from April through October, was not able to operate during 
the month of April in the years 2019 to 2024 due to weather conditions 
that made the access roads to the sites impassible.\28\ For this 
reason, Echo Summit was not able to meet the 3-year completeness 
criterion of 90 percent for the 2024 design value period. While Echo 
Summit did not have a valid design value for the previous five years, 
for the five most recent valid design value years (2010-2014) Echo 
Summit was not among the top 50 percent of design values for the 
Sacramento Metro area, was 0.016-0.031 ppm lower than the highest 
design value site, and below the 2008 ozone NAAQS.\29\
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    \28\ See 2024 CARB Annual Network Plan, Appendix B.
    \29\ CARB submitted a site closure request for the Echo Summit 
ozone monitor to EPA on February 10, 2025. CARB also requested a new 
ozone monitor at the South Lake Tahoe--Sandy Way monitoring station 
with a proposed start date of April 1, 2025. See letter from Michael 
Miguel, CARB, to Dena Vallano, EPA Region IX, dated February 10, 
2025. The EPA plans to act on these requests in the near future.
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     The North Highlands--Blackfoot Way monitoring site was 
shut down on August 1, 2022, due to sudden loss of the lease providing 
access to the monitor following the property's sale to another owner. 
SMAQMD notified the EPA of this abrupt closure via letter on July 28, 
2022, and documented it in its 2023 annual network plan.\30\ The North 
Highlands--Blackfoot Way monitoring site had design values that were 
0.006-0.012 ppm lower than the highest design value site for the five 
previous valid design value years of its operation (2016-2020), did not 
have the highest fourth-highest daily maximum 8-hour ozone 
concentration in the Sacramento Metro area in the last five years of 
operations (2018-2022), and has had design values below the 2008 ozone 
NAAQS since 2019.
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    \30\ See 2023 SMAQMD Annual Network Plan, Appendix E.
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     The Sloughhouse monitoring site failed an annual 
performance evaluation due to an incorrectly installed ozone 
calibrator, which resulted in data invalidation from July 2023 through 
April 2024.\31\ As a result, the site did not meet the 3-year 
completeness criterion of 90 percent and the 2023 and 2024 calendar 
years did not meet the annual completeness criterion of 75 percent. 
While Sloughhouse did not have valid design values for the previous two 
design values, the Sloughhouse monitoring site was 0.008-0.014 ppm 
lower than the highest design value site and not the fourth-highest 
daily maximum 8-hour ozone concentration in the Sacramento Metro area 
for the five previous valid design value years (2018-2022). Sloughhouse 
also had valid design values below the 2008 ozone NAAQS for 2018-2022.
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    \31\ See Data Certification Letter from Mark Loutzenhiser, 
SMAQMD, to Martha Guzman, EPA, dated January 15, 2025.
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    Historically, the design values for these sites have consistently 
measured 0.005-0.015 ppm lower than the highest design value site for 
the Sacramento Metro area.\32\ Therefore, we find that the invalid 
design values at the Echo Summit, North Highland--Blackfoot Way, and 
Sloughhouse monitoring sites do not preclude an attainment 
determination for the Sacramento Metro area. The remaining ozone 
monitoring sites meet the data completeness requirements of 40 CFR part 
50, Appendix P.\33\ Taking into account the extent and reliability of 
the applicable ozone monitoring network, and the data collected 
therefrom and summarized in Table 1 of this document, we are proposing 
to determine that the Sacramento Metro area attained the 2008 ozone 
NAAQS (as defined in 40 CFR part 50, Appendix P) by the applicable 
attainment date (i.e., December 31, 2024).
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    \32\ See ``SFNA O3 Design Value Report 2008-2024.pdf,'' which is 
included in the docket.
    \33\ See id.
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E. Effects of This Proposed Determination

    A determination of attainment by the attainment date does not have 
the effect of redesignating an area to attainment. Redesignation of an 
area to attainment requires that an area has met all applicable 
requirements of CAA section 110 and part D, and that the area has 
submitted, and the EPA has approved, a redesignation request and 
maintenance plan.\34\ Therefore, if we finalize this determination as 
proposed, the Sacramento Metro nonattainment will remain designated 
nonattainment for the 2008 ozone NAAQS, and will retain its current 
classification of Severe-15 for this standard. A determination of 
attainment by the attainment date applies throughout the attainment 
area, including to lands under jurisdiction of CARB and the Districts, 
and the lands under

[[Page 13321]]

jurisdiction of the Tribes mentioned in this document.
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    \34\ Memorandum dated September 4, 1992 from John Calcagni, 
Director, EPA Air Quality Management Division, to Regional Air 
Directors, titled ``Procedures for Processing Requests to 
Redesignate Areas to Attainment.''
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    Based on our proposed finding of attainment by the applicable 
attainment date, we are also proposing to find that the CAA requirement 
for a SIP to include attainment contingency measures and RFP 
contingency measures will no longer apply to the Sacramento Metro area 
for purposes of the 2008 ozone NAAQS. Under CAA section 172(c)(9), 
attainment contingency measures must be implemented only if the area 
fails to attain by the attainment date. Further, under CAA section 
182(g), ozone nonattainment areas classified ``Serious'' or higher are 
required to meet RFP emissions reduction ``milestones'' and to 
demonstrate compliance with those milestones only until the attainment 
date has been met. Therefore, if we finalize our proposed determination 
that the Sacramento Metro area has attained the 2008 ozone NAAQS by the 
attainment date, then attainment contingency measures for the 2008 
ozone NAAQS would never be required to be implemented, regardless of 
whether the area continued to attain the NAAQS, and RFP contingency 
measures could not be triggered and would therefore no longer be 
necessary.\35\ This proposed finding will not prevent the EPA from 
exercising its authority under the CAA to address any subsequent 
violations of the NAAQS.
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    \35\ See, e.g., 87 FR 42126, 42130 (July 14, 2022). See also 57 
FR 13498, 13564 (April 16, 1992) and Memorandum dated May 10, 1995, 
from John D. Seitz, Director, Office of Air Quality Planning and 
Standards, to EPA Regional Air Directors, Regions I-X, Subject: 
``Reasonable Further Progress, Attainment Demonstration, and Related 
Requirements for Ozone Nonattainment Areas Meeting the Ozone 
National Ambient Air Quality Standard'' (``Seitz Memo'') p. 4.
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    As noted in Section I.B of this notice, we are concurrently making 
an interim final determination to stay the offset sanction and to defer 
the highway funding sanction associated with the EPA's 2023 disapproval 
of the Sacramento Metro area's contingency measures submittal. The 
determination to stay and defer sanctions is based upon the proposed 
determination of attainment by the attainment date detailed in this 
document. A final determination of attainment by the attainment date 
would permanently stop the sanctions and FIP clocks triggered by the 
EPA's previous disapproval of the contingency measures requirement for 
the Sacramento Metro area, and would permanently lift the offset 
sanction that has been in place.\36\
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    \36\ See Seitz Memo p. 6.
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III. Action Summary

    We are proposing to determine that the Sacramento Metro area 
attained the 2008 ozone NAAQS by its December 31, 2024 attainment date, 
based on quality-assured and certified ambient air quality monitoring 
data from 2022 through 2024. In this same issue of the Federal 
Register, we are also issuing an interim final determination as 
described in Section II.E, effective upon publication, to stay the 
offset sanction and defer the highway funding sanction.
    The EPA is soliciting public comments on the proposed action, our 
rationale for the proposed action, and any other pertinent matters 
related to the issues discussed in this document. We will accept 
comments from the public on this proposal for the next 30 days and will 
consider comments before taking final action.

IV. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

    This action is not a ``significant regulatory action'' under the 
terms of Executive Order 12866 (58 FR 51735, October 4, 1993).

B. Paperwork Reduction Act (PRA)

    This rule does not impose an information collection burden under 
the provisions of the PRA of 1995 (44 U.S.C. 3501 et seq.). This action 
does not contain any information collection activities and serves only 
to propose a determination that the Sacramento Metro nonattainment area 
attained the 2008 ozone NAAQS by the December 31, 2024 attainment date.

C. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic 
impact on a substantial number of small entities under the RFA (5 
U.S.C. 601 et seq.). This action will not impose any requirements on 
small entities. The proposed determination of attainment by the 
attainment date for the 2015 ozone standards, does not in and of itself 
create any new requirements beyond what is mandated by the CAA.

D. Unfunded Mandates Reform Act (UMRA)

    This action does not contain any unfunded mandate as described in 
UMRA, 2 U.S.C. 1531-1538 and does not significantly or uniquely affect 
small governments. The action imposes no enforceable duty on any state, 
local or Tribal governments or the private sector.

E. Executive Order 13132: Federalism

    This action does not have federalism implications. It will not have 
substantial direct effects on the states, on the relationship between 
the national government and the states, or on the distribution of power 
and responsibilities among the various levels of government. The 
division of responsibility between the federal government and the 
states for purposes of implementing the NAAQS is established under the 
CAA.

F. Executive Order 13175: Coordination With Indian Tribal Governments

    Executive Order 13175 (65 FR 67249, November 9, 2000), requires EPA 
to develop an accountable process to ensure ``meaningful and timely 
input by Tribal officials in the development of regulatory policies 
that have Tribal implications.'' This action does not have Tribal 
implications, as specified in Executive Order 13175, because this 
determination will not impose substantial direct costs on Tribal 
governments or preempt Tribal law. The EPA has identified Tribal areas 
within the Sacramento Metro nonattainment area. We note that this 
determination, if finalized, would apply throughout the nonattainment 
area, including on Tribal lands within the nonattainment areas. 
However, as noted in Section II.E of this notice, the Sacramento Metro 
nonattainment area, including the Tribal lands within the nonattainment 
area, would remain designated nonattainment and would retain its 
existing classification.
    The EPA plans to notify the Tribes located within the boundaries of 
the Sacramento Metro nonattainment areas of this proposed 
determination. Because a final determination of attainment would not 
change the Tribe's existing nonattainment designation or 
classification, the EPA does not plan offer government-to-government 
consultation on this proposed determination, however, it is our 
practice to initiate government-to-government consultation at the 
request of any Tribe.

G. Executive Order 13045: Protection of Children From Environmental 
Health and Safety Risks

    EPA interprets Executive Order 13045 (62 FR 19885, April 23, 1997) 
as applying to those regulatory actions that concern environmental 
health or safety risks that EPA has reason to believe may 
disproportionately affect children, per the definition of ``covered 
regulatory action'' in section 2-202 of the Executive Order. This 
action is not

[[Page 13322]]

subject to Executive Order 13045 because it does not establish an 
environmental standard intended to mitigate health or safety risks.

H. Executive Order 13211: Actions That Significantly Affect Energy 
Supply, Distribution, or Use

    This action is not subject to Executive Order 13211 (66 FR 28355, 
May 22, 2001) because it is not a significant regulatory action under 
Executive Order 12866.

I. National Technology Transfer and Advancement Act (NTTAA)

    This rulemaking does not involve technical standards. Therefore, 
EPA is not considering the use of any voluntary consensus standards.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Incorporation by 
reference, Intergovernmental relations, Nitrogen oxides, Ozone, 
Reporting and recordkeeping requirements, Volatile organic compounds.

    Dated: March 11, 2025.
Cheree D. Peterson,
Acting Regional Administrator, Region IX.
[FR Doc. 2025-04791 Filed 3-20-25; 8:45 am]
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