U.S. EPA FACT SHEET
EPA Proposes Approval of California's Plan for the Sacramento Area
to Attain the 1997 Ozone National Ambient Air Quality Standard
September 24, 2014
Summary
•	EPA is proposing to approve California's plan for the Sacramento ozone nonattainment
area to attain the 1997 8-hour ozone National Ambient Air Quality Standard (1997 ozone
standard).
•	The attainment plan addresses numerous requirements in the Clean Air Act. Collectively,
these requirements will help the area attain by June 15, 2019, the attainment deadline for
the Sacramento nonattainment area.
•	In today's action, EPA is proposing to approve the following elements of plan for the
Sacramento area.
Attainment demonstration.
Emissions inventories.
Air quality modeling.
Reasonably available control measures.
Provisions for transportation control strategies and measures.
Rate of progress and reasonable further progress (RFP) demonstrations.
Transportation conformity motor vehicle emissions budgets.
Contingency measures for failure to make RFP or attain.
Commitments for the air districts to adopt additional measures.
•	Today's action signifies an important step in improving air quality and protecting public
health in the Sacramento ozone nonattainment area. This progress was accomplished
through the joint efforts of the Sacramento, El Dorado, Feather River, Placer, and Yolo-
Solano air districts, California Air Resources Board, and EPA.
Background
•	Breathing air containing ozone can reduce lung function and increase respiratory
symptoms, aggravating asthma or other respiratory conditions. Ozone exposure also has
been associated with increased susceptibility to respiratory infections, medication use by
asthmatics, and emergency department visits and hospital admissions for individuals with
respiratory disease. Ozone exposure may also contribute to premature death, especially in
people with heart and lung disease.

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U.S. EPA FACT SHEET
•	Ground-level ozone is formed when nitrogen oxides (NOx) and volatile organic
compounds (VOCs) react in the atmosphere in the presence of sunlight. NOx and VOCs
are called ozone precursors. Motor vehicle exhaust, industrial emissions, and chemical
solvents are the major sources of these chemicals. Ozone pollution is a concern especially
when the weather conditions needed to form it, lots of sun and hot temperatures, occur.
•	In April 2004, EPA designated the Sacramento area as nonattainment for the 1997 ozone
standard based on air quality data from 2001 through 2003.
•	Attainment is expected by June 15, 2019 as a result of substantial emissions reductions
(i.e., 53% for NOx and 33% for VOCs) occurring since 2002.
•	In proposing to approve of the State's attainment plan for the Sacramento area, EPA has
concluded that the area has met the plan approval criteria in sections 172 and 181-185 of
the Clean Air Act.
•	Today's action only concerns the 1997 ozone standard. Despite today's significant
milestone, the State currently does not expect the area to attain the 1997 ozone standard
before June 15, 2019, and the State will need to address the more stringent 2008 ozone
standard at a later date.
Next Steps
•	Today's action will be published in the Federal Register in approximately two weeks, and
EPA is providing a comment period of 30 days on the proposed rule. We will
respond to all comments in the final rule.
For More Information:
http://www.epa.gov/region9/air/actions/ca.html

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