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Facilities and Enforcement Activities Related to the Clean Air Act Stationary Source Program

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Overview of Clean Air Act (CAA) Stationary Source Program, Data Collection, and Information Sources

This page provides information on federal, state, tribal and local compliance monitoring and enforcement of Clean Air Act (CAA) requirements and implementation of CAA programs for stationary sources. Delegated state, local and tribal environmental agencies perform a significant percentage of the permitting, compliance monitoring and enforcement under the CAA. These agencies are required to regularly report to EPA facilitating EPA's oversight. In addition, EPA maintains the authority to also enforce all CAA requirements.

EPA collects key information, called minimum data requirements (MDR) , including, but not limited to:

Compliance and enforcement data is reported by EPA, state, local and tribal governments using EPA's Air Facility System (AFS), which also stores the data. The data can be searched and sorted using EPA's Enforcement & Compliance History Online (ECHO) Web site, which is updated monthly. An overview of data entry requirements is available. ECHO is also populated with data from other key EPA databases and programs including the National Emissions Inventory (NEI), Toxics Release Inventory (TRI) and Acid Rain Program.

On this page:

Finding CAA Program, and Compliance and Enforcement Data

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Local Air Quality and Facility Emissions Information

  1. What types of facilities are regulated by the Clean Air Act and how many are there?

    There are three main categories of stationary sources regulated by the CAA:

    1. Major Sources - facilities that can emit pollutants on an annual basis at a rate greater than thresholds established by CAA regulations. For example, a facility that can emit greater than 100 tons per year of any pollutant other than greenhouse gases is major under the Title V of the CAA;
    2. Synthetic Minor Sources (SM) - facilities that would be major but have federally enforceable permit limits to restrict their emissions below major source thresholds; and
    3. Minor or Area sources - facilities that physically cannot emit above major source thresholds.

    For more on the Title V permit program, please visit EPA's Operating Permits Web site.

    As of March 2010, there are 14,795 active major sources, and 145,236 active synthetic minor and other minor sources (collectively referred to as non-major sources). EPA does not require reporting of most minor sources and related data, with some exceptions (see Summary of Data Entry Requirements). Active sources are those that are operating, seasonal or temporarily operating. Therefore, the non-major universe count in EPA's national database does not include all minor facilities. However, some states do report minor facility data on a voluntary basis and additional facility universe data may be found on state and local agency Web sites.

    A compilation of regulated facilities by state can be downloaded below.

    The table provides a universe count for each state, as reported to EPA, of:

  2. Where can I find emissions and chemical release data for a facility?

    On the ECHO Search for Facilities – Clean Air Act page under Chemical Releases, users can find facilities that report emissions and chemical releases to the Toxics Release Inventory and those included in the National Emissions Inventory (2002).

    • TRI data is available annually. TRI mapping and query tools are available on the TRI Data Web site.
    • NEI is updated every three years, but includes data on criteria pollutant emissions as well as hazardous air pollutants. Current data is for 2005; the 2008 inventory is being developed and will include greenhouse gases. Customizable NEI reports and maps are available at EPA's Air Emission Sources Web page.

  3. How can I find air quality information for an area of interest to me?

    EPA maintains inventories of air quality data and facility emissions data. Air quality inventories are developed using monitoring data. Emissions inventories are developed using facility specific data. These data sets are complementary because facility emissions will affect an area's air quality.

    The Air Quality System (AQS) contains air monitoring data collected by EPA, state, local and tribal air pollution control agencies from thousands of monitoring stations. To search for data, visit:

    • AIRNow – Real-time air quality maps and daily AQI forecasts for over 300 US cities.
    • AirTrends – Air quality trends based on a nationwide network of monitoring sites for each criteria pollutant.
    • AirCompare – Interactive Web site that provides access to air quality information, based on specific health conditions of interest.
    • AirExplorer – Access to data from the AQS Data Mart for air quality analysts.
    • Clean Air Status and Trends Network (CASTNET) – Access to measurements of concentrations of air pollutants involved in acidic deposition affecting regional ecosystems and rural ambient ozone levels.

    The National Emissions Inventory contains source specific annual emissions data. To search data, visit:

    • Air Emission Sources – Database of facility, industrial sector, county and state criteria pollutant emission summaries.

    AirData provides an annual summary of air pollution data from both NEI and AQS.

    The ECHO Search for Facilities – Clean Air Act page allows a user to search for specific air emission sources or sources in a specific geographic area.

    Areas that do not meet a National Ambient Air Quality Standard for a criteria pollutant can be found using EPA's "The Green Book Nonattainment Areas for Criteria Pollutants".

  4. Where can I find information or data on greenhouse gas (GHG) emissions and concentrations?

    For an overview of GHG emissions, the EPA maintains the Greenhouse Gas Emissions Web page, additionally some states have developed GHG inventories that provide information on sources of GHG emissions.

  5. How can I find out about the health effects associated with various air pollutants?

    Air pollutants from stationary sources are basically broken down into two categories, criteria pollutants and hazardous air pollutants (HAPs).

    Criteria Pollutants

    An area's Air Quality Index indicates how clean or unhealthy the air is, and what associated health effects might be a concern. The "Air Quality Index - A Guide to Air Quality and Your Health (PDF)" (12 pp, 629K) explains the AQI and the negative health effects of the criteria pollutants.

    Health information is also available on EPA's Web site for each criteria air pollutant.

    Hazardous Air Pollutants

    For health information on hazardous air pollutants visit EPA's Health Effects Notebook for Hazardous Air Pollutants.

  6. How can I find exposure and risk data for the area in which a facility is located?

    You have three options:

    1. National Air Toxics Assessments (NATA) - Provides answers to questions about emissions, ambient air concentrations, exposures and risks across broad geographic areas, such as counties and states, at a specific time. The results cannot be used to identify exposures and risks for specific individuals.
    2. Risk-Screening Environmental Indicator (RSEI) – Analyzes factors that may result in chronic human health risks, but it is a screening tool; it is not a formal risk assessment.
    3. Integrated Risk Information System (IRIS) – Provides quantitative and qualitative risk information on effects that may result from exposure to environmental contaminants. To obtain a list of air pollutants emitted by a specific facility, use ECHO's Facility Search – Clean Air Act, you can select to view the Detailed Pollutant Report (2002 NEI data) from the output list or select the facility of interest and scroll to the TRI Total Releases (2007 HAP data).

    For more information on risk assessment, visit EPA's Risk Assessment Portal.

Facility-Specific Compliance and Enforcement Information

  1. How can I find CAA compliance and enforcement information for a specific facility?

    Use the ECHO Facility Search – Clean Air Act page to find a facility using the facility name, address, industrial classification, or size, among other things.

    Select the facility from the output list and a Detailed Facility Report will be provided that includes, among other things: 5 year history of compliance monitoring, informal enforcement actions and formal enforcement actions. For some facilities, an ICIS [Enforcement] Case Report will be available from the output list. ICIS is EPA's enforcement database of record. For the CAA, it includes only EPA data. State, tribal and local agencies do not report CAA enforcement data to ICIS.

  2. Where can I find information on EPA CAA enforcement actions?

    Use the ECHO Enforcement Cases Search page. This will provide all EPA enforcement actions concluded after September 30, 2000. In order to search for only CAA cases, under Case Attributes select Clean Air Act as the primary law. Refine the search further by selecting, for example, a specific facility or a specific state.

    EPA also posts Annual Enforcement Results, including an interactive map that can be used to search geographically.

    EPA's National Enforcement Trends report provides national and regional compliance and enforcement results and trends.

    For enforcement action highlights, visit the Compliance and Enforcement Newsroom

Statewide Compliance and Enforcement Information

  1. How can I find the number of compliance evaluations, violations and enforcement actions within a state?

    For an overview, please visist the EPA's Office of Compliance Inspections and Evaluations Web page.

    Data by year can be downloaded below (please visit EPA's state data comments page to access information provided by states regarding data discrepancies). These same reports are posted on the ECHO Analytics and Trends page under Additional Resources and Reports.

    Note: These 2009 annual reports also are available in Excel format on the ECHO Annual Reports Search page.

    To view a state's performance over time, the State Review Framework (SRF) CAA State Trends Report is available. The SRF is used to assess the adequacy of state and local compliance and enforcement programs.

  2. How can I compare my state's compliance and enforcement program to other states?

    ECHO provides multi-state reports for all SRF evaluation metrics. Select the metric of interest and whether you want the data provided in a table or graph.

    The reports below provide counts of the number of facilities with non-compliance identified by EPA or a delegated agency and permit deviations reported in each state (please visit EPA's state data comments page to access information provided by states regarding data discrepancies).

    2009 CAA Violations and Deviations (PDF) (7 pp, 172K)
    2008 CAA Violations and Deviations (PDF) (1 pg, 48K)

  3. Does EPA require that all violations or permit deviations at every air emission source be reported to them?

    No, EPA has identified a subset of violations as federally-reportable violations (PDF) (17 pp, 5.07MB). On a voluntary basis, some states do report all violations at all emissions sources.

    All deviations from a source's Title V permit are required to be reported to EPA and the permitting agency.

  4. How can I download historical summary and detailed information about federal and state compliance and enforcement activity?

    ECHO is a web interface that draws data from the Integrated Data for Enforcement Analysis (IDEA) system, which integrates facility data from different EPA databases, including AFS. The IDEA system moved from its previous platform at EPA to a mainframe that does not provide direct access to the public. In the event that the data retrievals available through ECHO do not meet your needs, data sets from the primary enforcement and compliance history databases in IDEA are available. Get data from IDEA.

    Also, beginning in 2008, EPA takes a "snapshot" of the data in ECHO. These frozen data sets are used during the SRF process and are reflected in the SRF Frozen National Reports. The snapshot will be taken annually. EPA has posted the national files in three different formats for use on ECHO's State Review Framework page. All three files contain the same information.

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Compliance and Data Reports

EPA's The Toxics Release Inventory (TRI) and Factors to Consider When Using TRI Data (PDF) (29 pp, 195K)

Air Quality Index - A Guide to Air Quality and Your Health (PDF) (12 pp, 333K)

Annual Reports

CAA Violations and Deviations


CAA Air Emission Sources

State Review Framework Frozen National Report

Data Downloads

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EPA is distributing this data to improve the transparency, utility and quality of the data and provide the public with tools and real-time access to better understand facility and state performance in these programs. EPA is not distributing this information to endorse, adopt, use or propose to use the information to support an Agency decision or position. The distribution of this material is therefore not a "dissemination" for purposes of EPA's Information Quality Guidelines.

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