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  • How does MOVES Classify Light-Duty Trucks?

    See More Frequent Questions about MOVES and Related Models . There are two definitions used in MOVES for light duty trucks. The source use type light duty trucks (sourceTypeID values of 31 or 32) use the Federal Highway Administration (FHWA) VM-1 definition of light duty vehicles used to report vehicle…

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  • Where can I find biomass emission limits for biomass burning in industry? I am looking for limits on particulate matter, SO2 and NOx.

    For information on EPA air emission standards for industrial sources, please visit this website. If you need additional help with specific questions, please use the contact us link on one of these pages to inquire further with staff in the emission standards program. New Source Performance Standards

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  • How are emissions trends compiled?

    For criteria air pollutants and precursors, the emissions trends are based on the triennial National Emissions Inventory data, with some interim year data included for non-triennial years. The methods and interim-year approaches are described on the “Development of Data” tab included with the data provided on the Air Pollutant Emissions…

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  • How do I get access to the Emissions Inventory System?

    Access to the Emissions Inventory System (EIS) is available to state, local, tribal agencies, their representatives (such as contractors), to multijurisdictional organizations (MJOs), and to EPA staff. The EIS is not available to the public. Instructions for access to the EIS is available in the Emissions Inventory System (EIS) User’s…

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  • What does an annual emissions value in the NEI represent (one year or multiple years)?

    The NEI provides total annual emissions for a single year.

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  • The FTP download is not working; what do I do?

    Option 1:  The FTP site is active, but some browsers are no longer supporting the ftp:// protocol.  You can access the same data by replacing “ ftp://newftp.epa.gov / ” with  “ https://gaftp.epa.gov/ ” and keep the rest of the URL the same.  The filenames you see will be shorter, but…

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  • The point source maps are not working on the NEI data tab. What do I do?

    The point source maps use a web service provided by Envirofacts. Please report your problem to the Envirofacts “Contact Us” page here .

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  • What sources make up the Sectors or Tiers used in the emissions data summaries?

    Tier 1 and Sector categories are assigned by source classification codes (SCCs) that are the most specific processes available in the NEI. The latest SCC list with the Tier 1 and Sector assignments can be downloaded from the EPA SCC website in Comma Separate Values (CSV) format.

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  • Are the GHGs in the National Emissions Inventory Complete?

    No, the 2020 National Emissions Inventory (NEI) does not comprehensively capture all sources and sinks of greenhouse gases (GHGs) in the United States. For this information, users should review the EPA’s annual Inventory of U.S. Greenhouse Gas Emissions and Sinks . However, the NEI does report GHG emissions for select…

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  • What is the Relationship Between Calendar Year, Model Year, and Age?

    See More Frequent Questions about MOVES and Related Models . Model year (modelYearID) corresponds to the year that a group of vehicles in the fleet was produced. Calendar year (yearID) is the analysis year as selected in the ‘Time Spans/Year’ panel of the MOVES GUI. For a given calendar year…

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  • Where can I obtain the hourly data from Continuous Emissions Monitors (CEMs)?

    The CEM emissions data are available from the EPA Clean Air Markets Program Data website.

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  • What are EPA’s plans for the 2020 National Emissions Inventory given the atypical situation from COVID-19 that is impacting emissions? What will it be used for?

    The EPA intends to prepare a 2020 National Emissions Inventory in collaboration with state, local, and tribal air agency partners. The Air Emissions Reporting Rule (AERR) requires states and delegated local and tribal agencies to report emissions from stationary sources and provide model inputs for onroad and nonroad sources (except…

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  • How often are the NEI data updated and how frequently are the data published?

    The full NEI is created for every third inventory year (e.g., 2008, 2011, 2014, and 2017). The data for each version has been updated two times each for the 2008, 2011, and 2014 NEI cycles. For the 2017 NEI and beyond, the EPA is trying to publish only a single…

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  • What are the units of NEI emissions data?

    NEI emissions values represent total annual emissions for the inventory reporting year. Criteria air pollutants and precursors (CAPs) are reported in short tons per year , and hazardous air pollutants (HAPs) are reported in lbs per year .

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  • What is the definition of VOC?

    There is a regulatory definition of VOC. It is found in 40 CFR 51.100. CFR - code of federal regulations. The definition relates to the intent and requirements of the Clean Air Act. Excerpt from “Volatile Organic Compounds” Definition per 40 CFR Part 51.100(s): " Volatile organic compounds (VOC) means…

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