Emissions factors have long been the fundamental tool in developing national, regional, state, and local emissions inventories for air quality management decisions and in developing emissions control strategies. More recently, emissions factors have been applied in determining site-specific applicability and emissions limitations in operating permits by federal, state, local, and tribal agencies, consultants, and industry. AP-42 is a compendium of EPA recommended emissions factors.

The CMAQ Model Outputs data asset includes current and projected future levels of ambient concentrations and deposition to support regulatory impact analyses.

These files contain the publicly available data from the GHG Reporting Program for 2010. This data includes non-confidential data reported by facilities that directly emit GHGs. The files also contain non-confidential information reported by suppliers of fossil fuels and industrial gases. The files include data in both HTML (human readable) and XML format. For more information on the GHG Reporting Program and this data, please visit http://epa.gov/ghgreporting

EPA regulations codified in 40 CFR Part 60 and 63 require affected sources to perform emissions source tests, conduct continuous emissions monitoring, and submit compliance and emissions reports . EPA is promulgating "E-Reporting" rules to require affected sources to electronically submit source test results, emissions monitoring data, compliance reports, and emissions reports to EPA. As a result the EPA has developed the Compliance and Emissions Data Reporting Interface (CEDRI) which is located on EPA's Central Data Exchange (CDX). The CDX Web is the application used by EPA programs and various stakeholders to manage environmental data transmitted to EPA in order to meet EPA's reporting requirements.

The EPA Control Measure Dataset is a collection of documents describing air pollution control available to regulated facilities for the control and abatement of air pollution emissions from a range of regulated source types, whether directly through the use of technical measures, or indirectly through economic or other measures.

The EPA Control Strategy Tool (CoST) is a software tool for projecting potential future control scenarios, their effects on emissions and estimated costs. This tool uses the NEI and the Control Measures Dataset as key inputs. CoST outputs are projections of future control scenarios.

The Air Emissions Trends site provides national trends of criteria pollutant and precursor emissions data based on the the National Emissions Inventory (NEI) from 1970 - the latest NEI year.

The EV-GHG Mobile Source Data asset contains measured mobile source GHG emissions summary compliance information on light-duty vehicles, by model, for certification as required by the 1990 Amendments to the Clean Air Act, and as driven by the 2010 Presidential Memorandum Regarding Fuel Efficiency and the 2005 Supreme Court ruling in Massachusetts v. EPA that supported the regulation of CO2 as a pollutant. Manufacturers submit data on an annual basis, or as needed to document vehicle model changes. This asset will be expanded to include medium and heavy duty vehicles in the future.The EPA performs targeted GHG emissions tests on approximately 15% of vehicles submitted for certification. Confirmatory data on vehicles is associated with its corresponding submission data to verify the accuracy of manufacturer submissions beyond standard business rules.Submitted data comes in XML format or as documents, with the majority of submissions sent in XML, and includes descriptive information on the vehicle itself, emissions information, and the manufacturer's testing approach. This data may contain proprietary information (CBI) such as information on estimated sales or other data elements indicated by the submitter as confidential. CBI data is not publically available; however, CBI data can accessed within EPA under the restrictions of the Office of Transportation and Air Quality (OTAQ) CBI policy [RCS Link]. Pollutants data includes CO2, CH4, N2O. Datasets are divided by vehicle/engine model and/or year with corresponding emission, test, and certification data. Data assets are stored in EPA's Verify system.Coverage began in 2011, with summary light duty data available to the public on request. Raw data is only available to select EPA employees.EV-GHG Mobile Source Data submission documents with metadata, certificate and summary decision information is stored in Verify after it has been quality assured. Where summary data appears inaccurate, OTAQ returns the entries for review to their originator.

The Emissions Modeling Clearinghouse (EMCH) supports and promotes emissions modeling activities both internal and external to the EPA. Through this site, the EPA distributes and documents emissions datasets that are formatted for use in emissions models, which are used for emissions preparation for air quality modeling. The inventory data on this site are dervied from previous and current versions of the National Emission Inventory (NEI). This site also distributes the EPA's latest versions of ancillary datasets used to support the temporal, spatial, speciation, and future-year projection of these emissions.

The Engine and Vehicle Compliance Certification and Fuel Economy Inventory contains measured emissions and fuel economy compliance information for light duty vehicles. Data is collected by EPA to certify compliance with the applicable fuel economy provisions of the Energy Policy and Conservation Act (EPCA) and The Energy Independent Security Act of 2007

This asset provides identification data on renewable fuel producers, importers, laboratories, and facilities.

This asset includes compliance data (registrations and reports), including reports related to reformulated gasoline and conventional gasoline (anti-dumping), gasoline sulfur, mobile source air toxics (including gasoline benzene), sulfur content of on-road and non-road diesel fuel, and renewable fuels under 40 CFR Part 80; and includes registration and compositional information related to fuels and fuel additives under 40 CFR Part 79.

This tool to gives you access to greenhouse gas data reported to EPA by large facilities and suppliers in the United States through EPA's Greenhouse Gas Reporting Program. The tool allows you to view data in several formats including maps, tables, charts and graphs for individual facilities or groups of facilities. You can search the data set for individual facilities by name or location or filter the data set by state or county, industry sectors and sub-sectors, annual facility emission thresholds, and greenhouse gas type. For more information on the GHG Reporting Program and this data, please visit https://www.epa.gov/ghgreporting

The Engine and Vehicle Compliance Certification and Fuel Economy Inventory contains measured emissions and fuel economy compliance information for all types of vehicles (mobile sources of air pollution) excluding snowmobile, marine (diesel), and heavy duty engines whichsummary data is updated on an annual basis. Data is collected by EPA to certify compliance with the applicable fuel economy provisions of the Clean Air Act, Energy Policy and Conservation Act (EPCA) and the Energy Independent Security Act (EISA) of 2007.

The Mobile Source Emissions Regulatory Compliance Data Inventory data asset contains measured summary compliance information on light-duty, heavy-duty, and non-road engine manufacturers by model, as well as fee payment data required by Title II of the 1990 Amendments to the Clean Air Act, to certify engines for sale in the U.S. and collect compliance certification fees. Data submitted by manufacturers falls into 12 industries: Heavy Duty Compression Ignition, Marine Spark Ignition, Heavy Duty Spark Ignition, Marine Compression Ignition, Snowmobile, Motorcycle & ATV, Non-Road Compression Ignition, Non-Road Small Spark Ignition, Light-Duty, Evaporative Components, Non-Road Large Spark Ignition, and Locomotive. Title II also requires the collection of fees from manufacturers submitting for compliance certification. Manufacturers submit data on an annual basis, to document engine model changes for certification. Manufacturers also submit compliance information on already certified in-use vehicles randomly selected by the EPA (1) year into their life and (4) years into their life to ensure that emissions systems continue to function appropriately over time.The EPA performs targeted confirmatory tests on approximately 15% of vehicles submitted for certification. Confirmatory data on engines is associated with its corresponding submission data to verify the accuracy of manufacturer submission beyond standard business rules.Section 209 of the 1990 Amendments to the Clean Air Act grants the State of California the authority to set its own standards and perform its own compliance certification through the California Air Resources Board (CARB). Currently manufacturers submit compliance information separately to both the EPA and CARB. Currently, data harmonization occurs between EPA data and CARB data only for Motorcycle & ATV submissions.Submitted data comes in XML format or as documents, with the majority of submissions being sent in XML. Data includes descriptive information on the engine itself, as well as on manufacturer testing methods and results. Submissions may include information (CBI) such as information on estimated sales, new technologies, catalysts and calibration, or other data elements indicated by the submitter as confidential. CBI data is not publically available, but it is available within EPA under the restrictions of the Office of Transportation and Air Quality (OTAQ) CBI policy [RCS Link]. Pollution emission data covers a range of Criteria Air Pollutants (CAPs) including carbon monoxide, hydrocarbons, nitrogen oxides, and particulate matter. Datasets are segmented by vehicle/engine model and year, with corresponding emission, test, and certification data. Data assets are primarily stored in EPA's Verify system. Data collected from the Heavy Duty Compression Ignition, Marine Spark Ignition, Heavy Duty Spark Ignition, Marine Compression Ignition, and Snowmobile industries, however, are currently stored in legacy systems the will be migrated to Verify in the future.Coverage began in 1979, with early records being primarily paper documents that did not go through the same level of validation as the digital submissions that began in 2005.Mobile Source Emissions Compliance documents with metadata, certificate and summary decision information is made available to the public through EPA.gov via the OTAQ Document Index System (http://iaspub.epa.gov/otaqpub/).

The Monitoring Knowledge Base (MKB) is a compilation of emissions measurement and monitoring techniques associated with air pollution control devices, industrial process descriptions, and permitting techniques, including flexible permit development. Using MKB, one can gain a comprehensive understanding of emissions sources, control devices, and monitoring techniques, enabling one to determine appropriate permit terms and conditions.

OTS is an internal EPA national tribal database to assist the Regions and HQs in tracking tribal performance information.

This asset provides data on regional air quality, including trace level SO2, nitric acid, ozone, carbon monoxide, and NOy; and particulate sulfate, nitrate, and ammonium from 1989 to present. Precipitation and meteorology are provided from 1989 to 2011.

This asset includes all data collected by EPA in support of this program to address greenhouse gas emissions, fuel consumption, and criteria pollutants (NOx and PM) associated with ground freight transportation operations.

This file contains a summary of the publicly available data from the GHG Reporting Program for 2010. This data includes non-confidential data reported by facilities that directly emit GHGs. The files also contain non-confidential information reported by suppliers of fossil fuels and industrial gases. This excel file contains the same information available in the Data Publication Tool. The file contains the most important, high-level information reported by direct emitters and suppliers and can be easily sorted to respond to many common queries. Please visit https://www.epa.gov/ghgreporting for more information on the data.

The Title V Permitting Statistics Inventory contains measured and estimated nationwide statistical data, consisting of counts of permitted sources, types of permits issued, and the timeliness of permit issuance, for the operating permits programs being implemented under CAA authority (40 CFR parts 70 and 71). This data is non-source specific. The statutory authority leading to the collection of this information comes from Title V of the Clean Air Act.Prior to July 2008, data collected on state permit programs (part 70) was not equivalent to that collected when EPA was the permitting agency (part 71). Current system includes semiannual data from 2006-present; prior data is archived.Data is currently not publicly available, certain statistical data has been made available in the past, but not currently. This data is mostly used for ICR and PART reporting purposes.