This glossary contains terms you may run across on this site or in some other EHS context.
Underground Injection Control (UIC): The program under the Safe Drinking Water Act that regulates the use of injection wells to pump fluids into the ground. For more information, see the Underground Injection Wells topic page.
Underground Storage Tank (UST): A tank located all or partially underground that is designed to hold gasoline or other petroleum products or chemical solutions. For more information, see the Underground Storage Tanks topic page.
Underground Tank: A hazardous waste storage tank in which the entire surface area is totally below the surface of and covered by the ground. Note: Underground tanks storing hazardous waste should not be confused with underground storage tanks storing petroleum products or hazardous substances (see the definition of Underground Storage Tank).
Universal Treatment Standards: EPA’s individual numerical treatment standards for hazardous waste land disposal.
Unsaturated Zone: The area above the water table where the soil pores are not fully saturated, although some water may be present.
Vapor Capture System: Any combination of hoods or ventilation systems that capture or contain organic vapors and direct them to an abatement or recovery device.
Variance: Government permission for a delay or exception in the application of a given law, ordinance, or regulation.
Ventilation/Suction: The act of admitting fresh air into a space to replace stale or contaminated air; achieved by blowing air into the space. For more information, see the Ventilation topic page.
Volatile: Description of any substance that evaporates easily.
Volatile Organic Compounds (VOC): An organic compound that readily evaporates under normal conditions or temperature and pressure. Examples of VOC include benzene, trichloroethylene, and vinyl chloride.
Vulnerable Zone: An area over which the airborne concentration of a chemical involved in an accidental release could reach the level of concern.
Waste: 1. Unwanted materials left over from a manufacturing process. 2. Refuse from places of human or animal habitation.
Waste Treatment Stream: The continuous movement of waste from generator to treater and disposer.
Waste Treatment Plant: A facility containing a series of tanks, screens, filters, and other processes by which pollutants are removed from water.
Wastewater: The spent or used water from individual homes, a community, a farm, or an industry that contains dissolved or suspended matter. For more information, see the Wastewater - General topic page.
Water Pollution: The presence in water of enough harmful or objectionable material to damage the water’s quality.
Water Quality Standards: State-adopted or EPA-approved ambient standards for water bodies. The standards cover the use of the water body and the water quality criteria that must be met to protect the designated use or uses.
Water Solubility: The maximum concentration of a chemical compound that may result when it is dissolved in water. If a substance is water soluble, it may readily disperse through the environment.
Well: A bored, drilled, or driven shaft, or a dug hole, whose depth is greater than the largest surface dimension and whose purpose is to reach underground water supplies or oil, or to store or bury fluids below ground.
Well Injection: The subsurface placement of fluids in a well. For more information, see the Underground Injection Wells topic page.
Well Monitoring: The measurement, by on-site instruments or laboratory methods, of the quality of water in a well.
Wetlands: An area that is regularly saturated by surface or groundwater and subsequently is characterized by a prevalence of vegetation that is adapted for life in saturated soil conditions (for example, cattails). For more information, see the Wetlands topic page.
Enviro Glossary Terms A
Enviro Glossary Terms B and C
Enviro Glossary Terms D and E
Enviro Glossary Terms F through H
Enviro Glossary Terms I through L
Enviro Glossary Terms M and N
Enviro Glossary Terms O and P
Enviro Glossary Terms Q and R
Enviro Glossary Terms S and T
Enviro Glossary Terms U through Z