This glossary contains terms you may run across on this site or in some other EHS context.
Abatement: Reducing the degree or intensity of, or eliminating, pollution.
Aboveground Tank: A waste storage tank that is situated in such a way that the entire surface area of the tank is completely above the plane of the adjacent surrounding surface and the entire surface area of the tank is able to be visually inspected. For more information, see the Aboveground Storage Tanks topic page.
Absorption: The passage of one substance into or through another; e.g., an operation in which one or more soluble components of a gas mixture are dissolved in a liquid.
Action Levels: In the Superfund program, the existence of a contaminant concentration in the environment high enough to warrant action or trigger a response under SARA and the National Oil and Hazardous Substances Contingency Plan. The term is used similarly in other regulatory programs; for example, in asbestos regulation.
Activated Sludge: Sludge that results when primary effluent is mixed with bacteria-laden sludge and then agitated and aerated to promote biological treatment. This speeds breakdown of organic matter in raw sewage undergoing secondary waste treatment.
Administrative Order: A legal document signed by EPA or an authorized state agency directing an individual, business, or other entity to take corrective action or refrain from an activity. It describes the violations and actions to be taken, and can be enforced in court. These orders may be issued as a result of an administrative complaint where the respondent is ordered to pay a penalty for statute violations.
Adsorption: 1: Adhesion of molecules of gas, liquid, or dissolved solids to a surface. 2: An advanced method of treating wastes in which activated carbon removes organic matter from wastewater.
Aeration: A process that promotes biological degradation of organic water. The process may be passive (when waste is exposed to air), or active (when a mixing or bubbling device introduces the air).
Ag Waste: Poultry and livestock manure and residual material in solid or liquid form generated from the production and marketing of poultry, livestock, fur-bearing animals, and/or their products. Also includes grain, vegetable, and fruit harvest residue. For more information, see the Ag Waste topic page.
Airborne Particulates: Total suspended particulate matter found in the atmosphere as solid particles or liquid droplets. Chemical composition of particulates varies widely, depending on location and time of year. Airborne particulates include windblown dust, emissions from industrial processes, smoke from burning wood or coal, and motor-vehicle exhaust.
Air Contaminant: Any particulate matter, gas, or combination, other than water vapor (see the individual GLOSSARY entry Air Pollutant).
Air Pollutant: Any substance in air that could, in high enough concentration, harm humans, animals, vegetation, or material. Pollutants may include almost any natural or artificial composition of matter capable of being airborne. They may be in the form of solid particles, liquid droplets, gases, or in combinations of these forms. They generally fall into two main groups: those emitted directly from identifiable sources; and those produced in the air by interaction between two or more primary pollutants, or by reaction with normal atmospheric constituents, with or without photoactivation.
Air Pollution: The presence of contaminant or pollutant substances in the air that do not disperse properly and interfere with human health or welfare, or produce other harmful environmental effects.
Air Quality Control Region: An area, designated by the federal government, in which communities share a common air pollution problem. Sometimes several states are involved.
Air Quality Standards: The level of pollutants prescribed by regulations that may not be exceeded during a specified time in a defined area.
Ambient Air: Any unconfined portion of the atmosphere, including open air and surrounding air.
Animal Feeding Operation: A lot or facility where animals have been, are, or will be stabled or confined and fed or maintained for a total of 45 days or more in an 12-month period and where crops, vegetation forage growth or post-harvest residues are not sustained over any portion of the lot or facility in the normal growing season. For more information, see the Ag Waste topic page.
Aquifer: An underground geological formation, or group of formations, containing usable amounts of groundwater that can supply wells and springs.
Area of Review: In the underground injection well control program, the area surrounding an injection well that is reviewed during the permit process to determine whether the injection operation will induce flow between aquifers.
Asbestos: A mineral fiber that can pollute air or water and cause cancer or asbestosis when inhaled. EPA has banned or restricted its use in manufacturing and construction. For more information, see the Asbestos topic page.
Ash: The mineral content of a product remaining after complete combustion, such as incineration.
Attainment Area: An area considered to have air quality as good as or better than the National Ambient Air Quality Standards as defined in the Clean Air Act. An area may be an attainment area for one pollutant, and a nonattainment area for others.
Enviro Glossary Terms A
Enviro Glossary Terms B and C
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