## Fact Sheet – Air Quality Designations for the 2010 Primary Nitrogen Dioxide (NO 2 

## ) National Ambient Air Quality Standards

ACTION

• On January 20, 2012, based on the mo st recent air quality monitoring data (2008-2010), the U.S. Environm ental Protection Agency has determined that no area in the country is violating the 2010 national air quality standards for nitrogen dioxide (NO 2 ).

• These areas have been designated as “unclassifiable/attainment.”

• EPA will work with states, tribes and local air quality agencies to ensure that air quality is maintained and public health is protected.

• Areas that are designated unclassifi able/attainment do not have to take steps to improve air quality but they must prevent their air quality from deteriorating to unhealthy levels. For example, Prevention of Significant Deterioration (PSD), a permitting program for industrial facilities, applies in these areas to ensure that new and modified sources of pollution do not cause or contribute to violations of air quality standards.

• EPA is working with state, tribal an d local air agencies to put in place additional NO 2 monitors that were required along with the 2010 standard. EPA expects this netw ork to be deployed in 2013.

BACKGROUND

• On January 22, 2010, EPA strengthened the health-based standard for NO 2 by setting a new 1-hour standard of 100 parts per billion (ppb). The new standard will protect public health, including the health of sensitive populations – people with asthma, children and the elderly.

• To determine compliance with the new standard, EPA established new ambient air monitoring and reporting requirements for NO 2
. In urban areas, monitors are re quired near major roads as well as in other locations where maximum concentrations are expected. Additional monitors are required in large urban areas to measure the highest concentrations of NO 2 that occur more broadly across communities.Working with the states, EPA will site a subset of monitors in locations to help protect communi ties that are susceptible and vulnerable to NO 2 -related health effects.

• EPA and State and Tribal agencies are currently working to establish an expanded network of NO 2 monitors, expected to be deployed in 2013. Once three years of air qualit y data have been collected from the expanded network EPA will be better able to determine NO 2 air quality in additional locations.

• Within two years of setting a new NAAQS or revising an existing standard, the Clean Air Act direct s EPA to formally identify or “designate” areas as “unclassifiable /attainment” (meeting the standard or no evidence indicating a violat ion), “nonattainment” (not meeting the standard), or “unclassifiable” (i nsufficient information to designate as attainment or nonattainment, but likely to be violating).

ABOUT DESIGNATIONS

• EPA is designating all areas in the country, both state lands and Indian country. Unlike states, tribes are no t obligated to submit designation recommendations but are invited to participate in the designations process by submitting a recommendat ion for Indian country and/or by engaging in formal or informal consultation with EPA and states.

• Once designations take effect, th ey become an important component of state, local and tribal gove rnments’ efforts to manage NO 2 pollution. The designations govern what subs equent regulatory actions states and EPA must take in order to improv e or preserve air quality in each

area.

FOR MORE INFORMATION

• For more information on the designation process for the NO 2 standards, and to view individual le tters from EPA to states and tribes, go to EPA’s Web site at www.epa.gov/air/nitrogenoxides/designations/