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 YoloSolano 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.
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