Criteria Pollutant Emission Inventory Data

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U.S. EPA National Ambient Air Quality Standards and Criteria Pollutants

The U.S. Environmental Protection Agency (U.S. EPA) establishes health-based ambient air quality standards to identify outdoor pollutant levels that are considered safe for the public - including those individuals most sensitive to the effects of air pollution, such as children and the elderly.

U.S. EPA has set National Ambient Air Quality Standards (NAAQS) for six pollutants, including ozone and particulate matter. These are referred to as the “criteria” pollutants.

Although there is some variability among the health effects of the six NAAQS pollutants, each has been linked to multiple adverse health effects including, among others, premature death, hospitalizations and emergency department visits for exacerbated chronic disease, and increased symptoms such as coughing and wheezing.

Below is the list of pollutants for which NAAQS were established. Learn more about the health and environmental effects specific to each pollutant.

Federal clean air laws require areas with unhealthy levels of ozone, inhalable particulate matter, carbon monoxide, nitrogen dioxide, and sulfur dioxide to develop plans known as State Implementation Plans (SIPs). SIPs are comprehensive plans that describe how an area will attain NAAQS.

California Emissions Inventory Data Analysis and Reporting System

The California Emissions Inventory Data Analysis and Reporting System (CEIDARS)is a database management system developed to track statewide criteria pollutant and air toxic emissions. The database is divided into reporting years and stores discrete information for

Stationary point: Stationary point sources are sources that can be identified by locations and are often permitted by local Air Quality Management Districts and Air Pollution Control Districts (Districts). Examples of stationary sources include facility point sources, such as power plants and oil refineries.
Areawide: Areawide sources are those that do not have specific locations and are spread over large areas, such as consumer products and unpaved roads.
Mobile: Mobile sources consists of onroad vehicles, such as passenger cars and trucks, motorcycles, busses, and heavy-duty trucks, and offroad sources, such as trains, ships, and boats.
Natural sources: Natural sources are non-anthropogenic sources that include vegetation (biogenic), petroleum seeps, and wildfires.

To view CEIDARS facility level emissions data, use the Facility Search Tool, which displays data from 1987 to 2018.

California Emissions Projection Analysis Model

The California Emissions Projection Analysis Model (CEPAM) was created to support SIP development, air quality modeling efforts, and the tracking of the progress of SIPs.

CEPAM starts with a base year, which is pulled from CEIDARS, and forecasts emissions for point and area sources using the most current growth and control data available at the time of the development of the model version. For mobile sources, CEPAM integrates the emission estimates from CARB's EMFAC and OFFROAD mobile source emission models to provide a comprehensive anthropogenic emission inventory. For more information on the development of emission estimates, click here.

The most current publically available version of CEPAM is CEPAM2019v1.03. It contains backcasts and forecasts from 2000 to 2050, derived from a 2017 base year inventory, chosen because it aligns with the National Emissions Inventory (NEI) reporting year and also represents the base year for the emission projections serving most of the SIPs that are currently underway for the 2015 70 ppb National Ambient Air Quality Standard (NAAQS) for ozone.

The table below summarizes the emissions generated by CEPAM2019v1.03 for the 2017 base year.

California Air Resources Board