Jump to main content or area navigation.

Contact Us

Area Designations for 1997 Fine Particle (PM2.5) Standards

Information provided for informational purposes only Note: EPA no longer updates this information, but it may be useful for historical purposes. See the PM Designations Home Page for more recent information about PM Designations.

This Web site provides information on the process EPA, the states and the tribes engage in to designate areas as "attainment" (meeting) or "nonattainment" (not meeting) the PM2.5 standards established in 1997.

The Clean Air Act requires EPA to issue designations after the agency sets a new National Ambient Air Quality Standard (NAAQS) or revises an existing standard. EPA formally designates areas as “nonattainment” (not meeting the standard), “unclassifiable/attainment” (meeting the standard or expected to be meeting the standard despite a lack of monitoring data), or “unclassifiable” (insufficient data to classify).

Once nonattainment designations take effect, the state and local governments have three years to develop implementation plans outlining how areas will attain and maintain the standards by reducing air pollutant emissions contributing to fine particle concentrations.

EPA strengthened the air quality standards for particle pollution in 2006. The Agency expects designations based on 2007-2009 air quality data will take effect in 2010.

This Web site contains the following information:

State Designations: EPA issued official designations for the PM2.5 standard on December 17, 2004 and made modifications in April 2005. They are summarized here.

Tribal Designations: EPA issued official designations for the PM2.5 standard on December 17, 2004. The designations impacting federally-recognized tribal lands are summarized here.

Regulatory Actions: Links to regulatory documents and information explaining regulatory actions related to PM2.5 emissions.

PM2.5 Conditions: Links to the AirNOW Web site with real-time information on PM2.5 conditions and web cameras around the country.

Air Quality Forecast: Links to the Air NOW Web site with PM2.5 air quality forecasts for dozens of cities around the country. 

Basic Information: Background on PM2.5 attainment issues and EPA actions to address PM2.5 emission concerns.

PM and Human Health: Information about the health effects of particle pollution. 

Policy Guidance: Links to EPA's April 2003 guidance on the designations process for the fine particle standards, and related fact sheet.

Technical Data: Links to air quality technical data used to determine an area's designation status.

Frequent Questions: Answers to common questions regarding fine particles and the designations process.

Related Links: Related sites offering further information and assistance.

Glossary: Explanations of the technical terms and acronyms used throughout the site.

A similar set of Web Pages exists for EPA's designated 8-hour ozone nonattainment areas designated in April 2004.  Visit the 8-hour ground-level ozone designations page to learn more about the ozone designations.

Jump to main content.