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Environmental Terms and Acronyms

If you are looking for a specific term or acronym, click the letter with which the word begins. Otherwise browse through the alphabetical listing.

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If you are not able to find a specific term or acronym on this page, you may want to try the DEQ glossary or EPA A to Z Index.


Air Quality Control Region
A geographic area within which air pollution is measured; usually a city and its surrounding counties and comprising two or more planning districts.

Area Source
Any stationary source that is not a major source of air pollutants. Emits less than 10 tons of a single hazardous air pollutant (HAP) or 25 tons of two or more hazardous air pollutants.

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Best Available Control Technology
The pollution control method that is recognized as the one removing the greatest amount of air pollutants for a particular industry or process. Cost is considered in determining and requiring BACT.

Best Available Retrofit Technology
The BART requirement applies to facilities built between 1962 and 1977 that have the
potential to emit more than 250 tons a year of visibility-impairing pollution. Those facilities fall into 26 categories, including utility and industrial boilers, and large industrial plants such as pulp mills, refineries and smelters. Many of these facilities previously have been exempt from federal pollution control requirements under the Clean Air Act.

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Clean Air Act
The Clean Air Act is the comprehensive Federal law that regulates air emissions from area, stationary, and mobile sources. This law authorizes the U.S. Environmental Protection Agency to establish National Ambient Air Quality Standards (NAAQS) to protect public health and the environment.

The act of securing a waste management facility in compliance with applicable requirements.

Criteria Pollutant
Any air pollutant for which EPA has established a National Ambient Air Quality Standard (NAAQS): carbon monoxide, lead, nitrogen oxides, ozone, particulates and sulfur oxides. Criteria pollutants are measured in air quality control regions to determine whether the area meets or does not meet the federal air quality standard.

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Discharge to State Waters
Release of pollution from a ditch, pipe or other conveyance to surface waters (lake, stream, creek, river or tidal wetland).

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General Permit
A set of conditions that can be standardized for a number of facilities; use of general permits where possible eliminates individualized permits for similar situations and is cheaper and less burdensome administratively than individual permits.

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Hazardous Air Pollutants (HAPs)
One of 187 substances and compounds for which EPA is establishing "maximum achievable control technology" (MACT) standards. A major source of HAPs is considered one that emits, or has the potential to emit, 10 tons per year of a single HAP or 25 tons per year of multiple HAPs.

Hazardous Material
Specific substances listed by EPA, and any other substance that is corrosive, ignitable, reactive or toxic.

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Joint Permit Application
An application for disturbing a waterway or wetland that when filed with the Virginia Marine Resources Commission is automatically distributed to the Department of Environmental Quality and the U.S. Army Corps of Engineers for determination of permit need by those agencies.

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Lowest Achievable Emission Rate
A control strategy which requires the lowest possible air emission rate for a type of facility for a specific pollutant; required of air pollution sources in air quality nonattainment areas.

Local Wetlands Board
A citizen board in some Tidewater jurisdictions that regulates tidal wetlands and sand dunes.

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Maximum Achievable Control Technology
A control strategy which requires the maximum achievable control technology for sources emitting a listed hazardous air pollutant, taking into consideration cost, non-air quality health and environmental impacts and energy requirements. Click here to visit the EPA website on Air Toxics.

Major Source
Term used to determine the applicability of Prevention of Significant Deterioration and new source regulations. In a nonattainment area, any stationary pollutant source with potential to emit more than 100 tons per year is considered a major stationary source. In PSD areas the cutoff level may be either 100 or 250 tons, depending upon the source. For sources subject to federal MACT rules, a major source is one that emits 10 tons per year of a single hazardous air pollutant or 25 tons per year of any combination of hazardous air pollutants.

Mobile Sources
Automobiles, aircraft, fleets of cars, trucks and other air pollution sources that move from place to place.

Modified Facility
Any stationary air pollution source that because of changes in equipment, processes or hours of operation emits new or increased pollutants.

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National Ambient Air Quality Standards
Maximum allowable concentrations of pollutants that EPA may reasonably anticipate to pose a danger to public health or welfare. When violated, the standards cause an area to be designated a nonattainment area. Concentrations are determined by modeling a prescribed geographic area.

National Emissions Standards for Hazardous Air Pollutants
Standards for asbestos, benzene, beryllium, inorganic arsenic, mercury, radionuclides and vinyl chloride.

Nonattainment Area
A geographic area that violates the National Ambient Air Quality Standards.

Non-criteria Pollutant
Any recognized and otherwise regulated air pollutants that are not listed as criteria pollutants.

New Source Performance Standards
Technology-based limits on air pollutants from new and modified sources.

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P2 - Pollution Prevention
Pollution prevention is an environmental management technique that uses source reduction techniques in order to reduce risk to public health, safety, welfare, and the environment, and, as a second preference, the use of environmentally sound recycling to achieve these same goals. Pollution prevention avoids cross-media transfers of wastes and/or pollutants and is multi-media in scope. It addresses all types of waste and environmental releases into the air, water, and land. The most common pollution prevention techniques include materials substitution, inventory management, equipment modifications, and process changes.

A simplified permitting process by which certain types of waste management facilities receive a permit upon submittal of required application materials, or in other cases, when DEQ acknowledges receipt of the required information.

Pollution Offsets
Air pollution reduction credits that offset any increased emissions resulting from a prospective new or expanding industry in a nonattainment area.

Potential to emit
the maximum capacity of a stationary source to emit a pollutant under its physical and operational design. Any physical or operational limitation on the capacity of the source to emit a pollutant, including air pollution control equipment, and restrictions on hours of operation or on the type or amount of material combusted, stored, or processed, shall be treated as part of its design only if the limitation or the effect it would have on emissions is federally and state enforceable. Secondary emissions do not count in determining the potential to emit of a stationary source.
This is measured for a period of 8760 hours. (24 hr/day x 7 days/wk x 52 wk/yr.)

POTW - Publicly Owned Treatment Works
A sewage treatment works, normally for treatment of sanitary sewage, owned by the state, a local government, utility authority or community.

Specialized industrial wastewater treatment, performed at the source, that makes the wastewater suitable for discharge to a public sewage system.

Prevention of Significant Deterioration
An air pollution permitting program, affecting sources that emits more than 250 tons of pollutant per year, intending to ensure that air quality does not diminish in attainment areas.

PSD Increment
The maximum increase in concentration that is allowed to occur above a baseline concentration for a pollutant while ensuring that an area continues to meet federal air quality standards.

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Reasonable Available Control Technology
Control technology that is both reasonably available, and both technologically and economically feasible. Usually applied to existing sources in nonattainment areas; in most cases is less stringent than new source performance standards.

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State Implementation Plan
A plan through which a state institutes air quality protection measures that meet federal criteria. When approved by EPA, the state is delegated federal authority for air quality regulation. All state air regulations, policies, guidance memoranda are considered part of the SIP.

Stationary Source
An air pollution source permanently located in a single location.

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Tidal Wetland
Any saltwater or freshwater wetland that is influenced by tidal action.

Listed pollutants recognized by Virginia or EPA as posing a potential risk to health or aquatic life. Emissions of toxics from industrial processes and waste management facilities are limited to avoid accumulations in the air, water or ground.

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Volatile Organic Compound
Any organic compound that participates in atmospheric photochemical reactions except those designated by EPA as having negligible photochemical reactivity.

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Virginia Department of
Environmental Quality
P.O. Box 1105
Richmond, VA 23218
(804) 698-4000

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