CCAA Glossary: Key Terms & Definitions for Developers and Consultants

CCAA Key Terms & Definitions

Air Basin: A geographic area in California that shares similar meteorological and geographic conditions, which is used for the purpose of managing air quality. The California Air Resources Board (CARB) has divided the state into 15 air basins.

Air District: A local or regional government agency responsible for regulating stationary sources of air pollution within its geographic jurisdiction, as well as for developing and implementing plans to attain and maintain state and federal ambient air quality standards. California has 35 local air districts.

Air Pollutant: Any substance that is emitted into or otherwise enters the atmosphere and that the California Air Resources Board has determined may affect the ambient air quality. This includes, but is not limited to, smoke, charred paper, dust, soot, grime, carbon, fumes, gases, odors, particulate matter, acids, or any combination thereof.

Air Quality Management Plan (AQMP): A plan developed by an air district to describe how it will attain and maintain state and federal ambient air quality standards. AQMPs are typically updated every three to five years.

Ambient Air: The air occurring at a particular time and place outside of structures. Often used interchangeably with "outdoor air."

Ambient Air Quality Standards: Health-based standards for clean air that identify the maximum amount of a pollutant that can be present in outdoor air without harm to public health. In California, ambient air quality standards are set by CARB for certain air pollutants, including ozone, particulate matter, carbon monoxide, nitrogen dioxide, sulfur dioxide, and lead.

Best Available Control Technology (BACT): An emission limitation based on the maximum degree of reduction of each air contaminant subject to regulation, which is achievable through application of production processes and available methods, systems, and techniques. BACT is determined on a case-by-case basis, taking into account energy, environmental, and economic impacts.

California Air Resources Board (CARB): The state agency responsible for protecting the public from the harmful effects of air pollution and developing programs and actions to fight climate change. CARB oversees all air pollution control efforts in California to attain and maintain health-based air quality standards.

California Clean Air Act (CCAA): A state law enacted in 1988 that establishes a legal mandate for air districts to achieve and maintain state ambient air quality standards by the earliest practicable date. The CCAA is codified in the California Health and Safety Code, Division 26.

Community Air Protection Program (CAPP): A program established by Assembly Bill 617 to reduce exposure in communities most impacted by air pollution. The program includes community air monitoring and community emissions reduction programs, as well as funding to support early actions to address localized air pollution.

Criteria Air Pollutant: An air pollutant for which acceptable levels of exposure can be determined and for which an ambient air quality standard has been set. Examples include ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide, and particulate matter.

Emission Inventory: A listing, by source, of the amount of air pollutants discharged into the atmosphere over a specified area within a specified time period.

Indirect Source: A facility, building, structure, installation, real property, road, or highway that attracts or generates mobile source activity that results in emissions of any pollutant for which there is a state ambient air quality standard.

Mobile Source: Sources of air pollution such as automobiles, motorcycles, trucks, off-road vehicles, boats, and airplanes. Contrast with stationary sources.

National Ambient Air Quality Standards (NAAQS): Standards established by the United States Environmental Protection Agency under authority of the Clean Air Act that apply for outdoor air throughout the country. There are NAAQS for six principal pollutants, which are called "criteria" air pollutants.

New Source Review (NSR): A permitting program established by the Clean Air Act that serves as a preconstruction permitting process for new and modified stationary sources located in areas that do not meet the National Ambient Air Quality Standards (nonattainment areas) and for other specified stationary sources.

Nonattainment Area: A geographic area identified by the United States Environmental Protection Agency and/or the California Air Resources Board as not meeting the National Ambient Air Quality Standards for a given pollutant.

Ozone: A pungent, colorless, toxic gas with direct health effects on humans, including respiratory and eye irritation and possible changes in lung functions. Ozone is a criteria air pollutant and a major component of smog.

Particulate Matter (PM): Any material, except pure water, that exists in the solid or liquid state in the atmosphere. The size of particulate matter can vary from coarse, wind-blown dust particles to fine particle combustion products.

Precursor: A directly emitted air contaminant that, when released to the atmosphere, forms, causes to be formed, or contributes to the formation of a secondary air contaminant for which an ambient air quality standard has been adopted. Examples include reactive organic gases and nitrogen oxides as precursors for ozone formation.

Reactive Organic Gas (ROG): A photochemically reactive chemical gas, composed of non-methane hydrocarbons, that may contribute to the formation of smog. Also sometimes referred to as Non-Methane Organic Gases (NMOGs).

State Implementation Plan (SIP): A plan prepared by each state, including California, describing existing air quality conditions and measures that will be taken to attain and maintain National Ambient Air Quality Standards.

Stationary Source: A fixed, non-mobile source of air pollution, usually found at industrial or commercial facilities. Examples include boilers, generators, and refineries.

Toxic Air Contaminant (TAC): An air pollutant, identified in regulation by CARB, which may cause or contribute to an increase in deaths or in serious illness, or which may pose a present or potential hazard to human health. TACs are considered under a different regulatory process than criteria air pollutants.

Transportation Control Measure (TCM): Any strategy to reduce vehicle trips, vehicle use, vehicle miles traveled, vehicle idling, or traffic congestion for the purpose of reducing motor vehicle emissions.

Volatile Organic Compound (VOC): Carbon-containing compounds that evaporate into the air, except for specific exempt compounds found to be non-photochemically reactive. VOCs contribute to the formation of smog and may themselves be toxic. VOCs often have an odor, and some examples include gasoline, alcohol, and the solvents used in paints.