Proposed Determinations of Attainment by the Attainment Date, Extension of the Attainment Date, and Reclassification of Several Areas Classified as Marginal for the 2015 Ozone National Ambient Air Quality Standards


Proposed Determinations of Attainment by the Attainment Date, Extension of the
Attainment Date, and Reclassification of Several Areas Classified as Marginal for the
2015 Ozone National Ambient Air Quality Standards

FACT SHEET

SUMMARY OF PROPOSED ACTION

•	On March 28, 2002, the U.S. Environmental Protection Agency (EPA) proposed
determinations as to whether 31 areas have achieved levels of ground-level ozone pollution
(or "smog") that meet the 2015 health-based air quality standards for ozone (known as the
National Ambient Air Quality Standards or NAAQS). This rulemaking, which is required by
the Clean Air Act, is necessary to ensure that smog-affected communities achieve healthy
air and implement the measures that the Clean Air Act requires to protect public health in
these areas.

•	These areas addressed in this proposal are currently classified as in "Marginal"
nonattainment, and were required to attain the standards by August 3, 2021. Within six
months after this attainment date, Clean Air Act (CAA) section 181(b)(2) requires EPA to
determine whether these areas attained the standard by the attainment date, and if not,
take specified actions to ensure these areas achieve attainment expeditiously.

•	Based on the most recent publicly available and certified ozone monitoring data for the
years 2018-2020, EPA is proposing to:

o Determine that six areas (Atlanta, GA; Manitowoc County, Wl; Southern Wasatch Front,
UT; Amador County, CA; San Francisco Bay, CA; and Yuma, AZ) attained the 2015 ozone
NAAQS by August 3, 2021.
o Grant the state of Utah's request for a 1-year attainment date extension to August 3,
2022, for the Uinta Basin, UT, nonattainment area because the area has met the
minimum Clean Air Act criteria and facts related to air quality trends and burden
support this proposal. The Ute Indian Tribe also requested an attainment date extension
for the Uinta Basin area and, while EPA's proposed extension is based on Utah's request
for the entire Uinta Basin area, the Agency also notes the Tribe's independent support,
o Determine that 24 areas failed to attain the 2015 ozone NAAQS by August 3, 2021. If
this proposed action is finalized, these 24 areas will be reclassified as Moderate and will
have a new attainment date of August 3, 2024:

1.	Allegan County, Ml

2.	Baltimore, MD

3.	Berrien County, Ml

4.	Chicago, IL-IN-WI

5.	Cincinnati, OH-KY

6.	Cleveland, OH

7.	Dallas-Fort Worth, TX

8.	Denver Metro/North Front Range, CO

9.	Detroit, Ml

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10.	Door County-Revised, Wl

11.	Greater Connecticut, CT

12.	Houston-Galveston-Brazoria, TX

13.	Louisville, KY-IN

14.	Mariposa County, CA

15.	Milwaukee, Wl

16.	Muskegon County, Ml

17.	North Wasatch Front, UT

18.	Pechanga Band of Luiseno Mission Indians of the Pechanga Reservation

19.	Philadelphia-Wilmington-Atlantic City, PA-NJ-MD-DE

20.	Phoenix-Mesa, AZ

21.	San Antonio, TX

22.	Sheboygan County, Wl

23.	St. Louis, MO-IL

24.	Washington, DC-MD-VA

EPA is also proposing to find that the states of Utah and Texas have not demonstrated that
the North Wasatch Front and San Antonio nonattainment areas, respectively, would have
timely attained the 2015 ozone NAAQS but for contributions from international sources.
Accordingly, EPA is proposing to disapprove demonstrations submitted by these states and
to find that these two areas have not attained by the attainment date.

Areas reclassified to Moderate face more protective Clean Air Act (CAA) requirements
designed to achieve attainment of the NAAQS by no later than August 3, 2024. These
requirements include stricter permitting requirements, implementing reasonably available
control technology for major sources and sources covered by certain EPA guidance
documents, basic vehicle inspection and maintenance (l/M) for urbanized areas, and the
submission of a new plan demonstrating how the area will attain expeditiously.

In order to ensure that these protections can be implemented by the attainment deadline,
EPA is proposing that states submit state implementation plan revisions addressing all
Moderate area requirements no later than January 1, 2023. EPA is also proposing in this
action that any controls that air agencies determine are needed for meeting CAA
requirements must be implemented as soon as possible but no later than January 1, 2023,
except for the basic vehicle l/M requirement, which we are proposing must be fully
implemented no later than 4 years after the effective date of reclassification.

The Pechanga Band of Luiseno Mission Indians of the Pechanga Reservation may, but is not
required to, submit a tribal implementation plan to EPA for approval for its nonattainment
area. Tribes with lands located in multi-jurisdictional nonattainment areas also may, but are
not required to, submit tribal implementation plans to EPA for approval.

The Clean Air Act requires these proposed actions to be based on air quality monitoring
data from the 2018-2020 time period - the three-year period immediately preceding the
August 2021 attainment date. Some areas may be attaining the 2015 ozone NAAQS based

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on more recent 2019-2021 data, however, and may be eligible for a redesignation to
attainment that could relieve such areas of certain planning and control requirements. EPA
will continue to work with individual states that have developed or are developing
redesignation requests and maintenance plans.

• EPA will accept comment on this proposal for 60 days after publication in the Federal

BACKGROUND

• On October 1, 2015, EPA strengthened the level of the NAAQS for ozone from 0.075 parts
per million (ppm) to a more protective 0.070 ppm.

• Effective on August 3, 2018 (September 24, 2018, for the San Antonio, Texas area), EPA
designated 52 areas throughout the country as nonattainment for the 2015 ozone NAAQS,
and the areas were classified as either Marginal, Moderate, Serious, Severe, or Extreme
depending on the severity of each area's ozone problems.

• Thirty-nine Marginal areas were required to attain the standards by August 3, 2021, along
with the San Antonio, Texas, area which was required to attain the standard by September
24, 2021. As required by section 181(b)(2) of the Clean Air Act, EPA is proposing next steps
for 31 of these areas in the proposed rule. EPA will be addressing the remaining nine areas
in separate actions.

FOR MORE INFORMATION

• To download a copy of the proposed action, go to EPA's Web site at:
https://www.epa.gov/ground-level-ozone-pollution/proposed-determinations-attainment-
attainment-date-extensions-O.

• The proposed action and other background information are also available either
electronically at http://www.regulations.gov. EPA's electronic public docket and comment
system.

• To review EPA's environmental justice policies and mandates, please visit:
https://www.epa.gov/environmentaliustice/learn-about-environmental-iustice.

• For further technical information about the rule, please contact Emily Millar with EPA's
Office of Air Quality Planning and Standards, at (919) 541-2619 or millar.emily@epa.gov.

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