A bulletin produced by Nebraska Department of Environmental Quality's
Air Quality Division
Nebraska Department of Environmental Quality
July 2008
FAQ’s about Attainment & Nonattainment

The purpose of this article is to explain what attainment and nonattainment means, how we know if an area is in attainment or nonattainment, and what the implications of each designation are to the citizens and industry in Nebraska.

What is ambient air?
Ambient air is the atmosphere, external to buildings, to which the general public has access. Areas within the fenced or restricted access boundaries of industrial facilities are generally not considered ambient air for the purposes of the air quality program. Workplace (indoor) air pollution exposure is regulated by the Federal Occupational Health and Safety Administration (OSHA).

What are the ambient air quality standards?
Air quality regulations in the United States are based on a set of air quality standards known as the National Ambient Air Quality Standards, or NAAQS. The primary NAAQS are set at the levels to protect the public health with “an adequate margin of safety.” Additionally, secondary NAAQS were created to protect the environment and public welfare. These standards are based on scientific studies conducted over many years. The standards are expressed as either micrograms per cubic meter or parts per million, over a specified period of time.

There are standards for six categories of pollutants, known as “criteria pollutants”: particulate matter less than ten and two and a half microns in diameter (PM10 and PM2.5), sulfur dioxide, nitrogen dioxide, ozone, carbon monoxide and lead. These pollutants can harm your health and the environment, and cause property damage. Of the six pollutants, particulate matter and ground-level ozone are the most widespread health threats. For more information related to these pollutants, view the “Air Pollutant Fact Sheet” on the Nebraska Department of Environmental Quality (NDEQ) website. The NAAQS can be found in Chapter 4 of Title 129 – Nebraska’s Air Quality Regulations.

What do the terms attainment and nonattainment mean?
If the concentration of one or more criteria pollutants in a geographic area is found to exceed the regulated or ‘threshold’ level for one or more of the NAAQS, the area may be classified as a nonattainment area. Areas with concentrations of criteria pollutants that are below the levels established by the NAAQS are considered either attainment or unclassifiable areas.

How do we know if an area is in attainment or not?
NDEQ has several ambient air monitors located throughout the state to measure the concentrations of pollutants in the ambient air. A summary of Nebraska ambient monitoring data is published annually in the “Nebraska Air Quality Report,” which can be found on NDEQ’s website.

Has Nebraska ever had a nonattainment area designation?
Yes, the most recent nonattainment area in Nebraska, was one for the pollutant lead. That nonattainment area was located in Omaha. Due to efforts from NDEQ, EPA, Omaha Air Quality Control, and the local industries, the area came back into attainment in 2001.

The Cass County/Weeping Water area came very close to the nonattainment designation for particulate matter less than 10 microns in diameter (PM10). Exceedences or near exceedences of the NAAQS were measured between 1998-2000. The NDEQ and the Cass County Air Conservation Commission (CCACA), an industry organization, began working on an emissions reduction action plan in 1999. The CCACA, as well as local, state and federal government agencies began a project that was based on the voluntary reduction of emissions from the local rock production companies located in that area.

Emissions reductions plans were developed and implemented. Because of the positive response and involvement of multiple levels of government, EPA allowed Nebraska to continue with the voluntary process instead of requiring the Governor to issue a declaration of nonattainment in the Weeping Water area for the exceedences of the NAAQS. The voluntary measures continue and the area has not measured the high readings as it had in previous years.

Currently, all areas in Nebraska are either in attainment or are unclassifiable. However, as EPA continues to revise and tighten ambient standards, Nebraska’s attainment status could change in the future. See the related article in this edition of AirWaves “EPA Tightens Ozone Standards - Implications for Nebraska.”

What will be required if an area is designated nonattainment?
A state implementation plan (SIP) must be submitted to EPA for the nonattainment area. Through this plan, a state will design its approach to reducing the pollutant levels in the air and, if appropriate, any emissions of precursor pollutants. Precursors are those pollutants which can form another pollutant in the atmosphere. For example, VOCs and NOx are precursor pollutants for ozone. The comprehensive approach to reducing criteria air pollutants taken by the Clean Air Act covers many different sources and a variety of clean-up methods.

These air pollution control programs could include the nonattainment New Source Review permit program and Federal General Conformity and Transportation Conformity programs. State plans will make sure power plants, factories and other pollution sources meet clean-up goals by working through the air pollution permitting process that applies to industrial facilities. Working with the EPA, a state or local authority will also implement programs to further reduce emissions of pollutant precursors from sources such as cars, fuels, and consumer/commercial products and activities.

After the area is designated as nonattainment, the area must meet the federally mandated deadlines established by the 1990 Amendment to the Clean Air Act for compliance with the national ambient air quality standards. In the interim, it must be demonstrated to the EPA that reasonable further progress toward improving the air quality is being made in the nonattainment area.

Is economic development impacted in a nonattainment area?
Economic development would not be impacted directly by a nonattainment designation, but there could be indirect, costly consequences due to the designation. Industrial facilities could be required to install pollution control equipment, take limits on their production, or otherwise find reductions in emissions by “offsetting” in order to expand. New facilities wanting to locate in a nonattainment area will most likely be required to install pollution controls or take stringent operational limits.

Voluntary measures to reduce emissions may also be implmented in the nonattainment area. Mobile vehicle emissions contribute to the formation of ozone and PM2.5. A nonattainment area strategy may include improvement to its mass transit systems and provide incentives or encouragement to reduce emissions from motor vehicles such as introducing carpool lanes and a centralized carpool list; providing incentives to utilize mass transit; encouraging refueling at different times of the day; encouraging biking and walking; reducing idling emissions especially from diesel buses and trucks; providing incentives to utilize renewable fuels; and many other measures to encourage behaviors from the general public that may impact the local air quality.

Are surrounding communities impacted from a nonattainment designation?
Air pollution knows no boundaries. Many factors contribute to the fate and transport of pollutants including local or regional topography, wind direction and speed, weather patterns, type of pollutant, and sources of the pollutant. Due to these factors, it is possible for communities surrrounding a nonattainment area to be impacted by pollution in the nonattainment area.

The state or local permitting authority or EPA may conduct a computer modeling analysis to help determine how the pollution in the region is being transported and what areas or sources are contributing to the regional pollution. Based on this analysis, the state or local air quality authority may need to work with the surrounding communities that potentially impact the nonattainment area to reduce their emissions. The degree to which surrounding communities or businesses must reduce their emissions will depend on their level of contribution, the type of pollutant, sources of the pollutant, and other factors specific to that region.

If you have questions related to nonattainment areas, contact the NDEQ Air Quality Division at (402) 471-2189.

For more information, contact

Nebraska Department of Environmental Quality
1200 "N" Street, Suite 400
P.O. Box 98922
Lincoln, Nebraska 68509
(402) 471-2186 FAX (402) 471-2909