Standards and Nonattainment Designations
Particle pollution’s harmful effects on human health and the environment prompted the federal government to set air quality standards for the amount of particle pollution in the air over certain time periods. Counties that do not meet these federal standards receive a nonattainment designation that triggers increased pollution control requirements for businesses in the area, along with other efforts to reduce particle pollution levels. This page includes an overview of particle pollution standards and links to more information about nonattainment designation.
Nonattainment Designation
When a county is identified as not meeting a federal air quality standard based on monitored values of the outside air, it is designated by the U.S. Environmental Protection Agency as nonattainment and given a target date to meet the standard. State plans are then prepared that include regulations for controls on emissions needed to reduce the air pollution and meet the standard. If at any time monitored values show that air quality has improved and the county now meets the standard, the state can request USEPA to redesignate the county to attainment status.
On October 8, 2009 the EPA issued new information regarding PM2.5 designations.
Overview of Particle Pollution Standards
The federal Clean Air Act requires the U.S. Environmental Protection Agency (EPA) to develop two types of air quality standards for key air pollutants:
- Primary standards protect public health, including the health of groups especially affected by air pollution, such as individuals with asthma or cardiac disease, children and the elderly.
- Secondary standards protect public welfare and the environment, including protection against damage to animals, crops and buildings.
EPA is required to set a primary standard at a level that protects public health with an adequate margin of safety. EPA is required to set a secondary standard at a level that protects public welfare and the environment from any known or anticipated adverse effects.
There are three primary national ambient standards for particle pollution.
- Annual PM2.5 – 15µg/m3 (arithmetic annual mean concentration)
- 24-Hour PM2.5 – 35 µg/m3 (98th percentile average concentration)
- 24 Hour PM10 – 150 µg/m3 (maximum concentration)
The secondary standards are currently the same as the primary standard for particle pollution. For more details see EPA's Web site on the National Ambient Air Quality Standards [exit DNR]
For more specific regulatory requirements related to particle pollution standards, visit the Particle Pollution Control Strategies and Regulations Web page.
Attainment Demonstrations
An attainment demonstration is a plan that ensures that an area with an air quality problem (nonattainment area) will attain the air quality standards in the requisite time period. The plan contains the necessary analyses and control program to demonstrate that enough pollutants have been removed from the atmosphere so that pollutant concentrations will not exceed the federal standard in the future.
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