U.S. EPA FACT SHEET
EPA Proposes to Redesignate the Yuba City-Marysville Area to Attainment for the
Fine Particulate Matter National Ambient Air Quality Standard
September 29, 2014
Summary
•	EPA is proposing to approve California's request to redesignate the Yuba City-
Marysville area to attainment for the 2006 fine particulate matter 24-hour National
Ambient Air Quality Standard (2006 24-hour PM2.5 NAAQS). These particles are
commonly referred to as PM2.5 because they have a diameter of 2.5 micrometers or less.
•	EPA is also proposing to approve California's plan demonstrating that the Yuba City-
Marysville area will maintain the 2006 24-hour PM2.5 NAAQS for at least ten years, the
attainment year emissions inventory, and motor vehicle emissions budgets.
•	Today's actions represent a significant milestone in air quality improvement
accomplished through the combined efforts of the Feather River Air Quality Management
District, the California Air Resources Board, and EPA.
Background
•	In January 2013, EPA issued a determination that the Yuba City-Marysville
nonattainment area attained the 2006 24-hour PM2.5 standard based on complete, quality-
assured, and certified ambient air monitoring data for the 2009-2011 monitoring period.
Particulate Matter and Public Health
•	Reducing PM2.5 levels is essential because fine particles can reach the deepest regions of
the lungs and exposure is linked to a variety of significant health problems including
damage to lung tissue, cancer and premature death.
•	PM2.5 can be emitted directly into the atmosphere or formed in the atmosphere as a result
of various chemical reactions from emissions of nitrogen oxides (NOx), sulfur dioxide,
volatile organic compounds (VOCs), and ammonia.
Next Steps
•	Today's proposed action will be published in the Federal Register in approximately two
weeks and include a 30-day period for public comment.
•	After the close of the comment period, EPA will evaluate the comments and respond to
them in subsequent rulemaking action.
For More Information:
http://www.epa.gov/region9/air/actions/ca.html

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