SDWA PWSS Program Permit Glossary: Key Terms & Definitions for Developers and Consultants

SDWA PWSS Program Permit Key Terms & Definitions

Best Available Technology (BAT): The best available technology that is economically achievable for treating a specific contaminant or group of contaminants in drinking water, as determined by the EPA. BAT is used to set maximum contaminant level goals (MCLGs) and national primary drinking water regulations (NPDWRs) (42 U.S.C. §300g-1(b)(4)(D)).

Contaminant: Any physical, chemical, biological, or radiological substance or matter in water (42 U.S.C. §300f(6)).

Disinfectant: Any oxidant, including but not limited to chlorine, chlorine dioxide, chloramines, and ozone, added to water in any part of the treatment or distribution process for the purpose of killing or inactivating pathogenic microorganisms (40 C.F.R. §141.2).

Disinfection Byproduct: A compound formed by the reaction of a disinfectant with organic or inorganic matter present in the water (40 C.F.R. §141.2).

Emergency Response Plan: A plan that outlines the actions a public water system will take in response to a variety of emergency situations, such as water supply contamination, natural disasters, or system failures (42 U.S.C. §300i-2(a)).

Filtration: A process for removing particulate matter from water by passing it through porous media (40 C.F.R. §141.2).

Groundwater: Water that is located beneath the surface in the saturated zone and is under a pressure equal to or greater than atmospheric pressure (40 C.F.R. §141.2).

Maximum Contaminant Level (MCL): The maximum permissible level of a contaminant in water delivered to any user of a public water system (42 U.S.C. §300f(3)).

Maximum Contaminant Level Goal (MCLG): The level of a contaminant in drinking water below which there is no known or expected risk to health, allowing for an adequate margin of safety (42 U.S.C. §300g-1(b)(4)(A)).

National Primary Drinking Water Regulations (NPDWRs): Legally enforceable standards that apply to public water systems and limit the levels of contaminants in drinking water (42 U.S.C. §300f(1)).

Operator Certification: A process whereby a state or the EPA certifies that an individual has met the necessary educational, experience, and examination requirements to operate a public water system (42 U.S.C. §300g-8).

Primacy Agency: The state or territorial agency responsible for implementing and enforcing the Safe Drinking Water Act and overseeing public water systems' compliance with the requirements (42 U.S.C. §300g-2).

Public Water System: A system that provides water for human consumption through pipes or other constructed conveyances to at least 15 service connections or serves an average of at least 25 individuals daily for at least 60 days out of the year (42 U.S.C. §300f(4)(A)).

Radionuclide: An unstable form of a chemical element that radioactively decays, resulting in the emission of nuclear radiation (40 C.F.R. §141.2).

Sanitary Survey: An onsite review of the water source, facilities, equipment, operation, and maintenance of a public water system to evaluate the adequacy of such elements for producing and distributing safe drinking water (40 C.F.R. §141.2).

Source Water: The water in its natural state, prior to any treatment, that is used to supply a public water system (40 C.F.R. §141.2).

Source Water Assessment: A process used to delineate the boundaries of the areas providing source waters for public water systems, identify the origins of regulated contaminants in the delineated area, and determine the susceptibility of the public water systems to those contaminants (42 U.S.C. §300j-13(a)(2)).

Supplier of Water: Any person who owns or operates a public water system (42 U.S.C. §300f(5)).

Surface Water: All water that is open to the atmosphere and subject to surface runoff (40 C.F.R. §141.2).

Technical, Managerial, and Financial (TMF) Capacity: The ability of a public water system to consistently provide safe drinking water, as demonstrated by having adequate technical, managerial, and financial resources (42 U.S.C. §300g-9(a)).

Treatment Technique: A required process intended to reduce the level of a contaminant in drinking water (42 U.S.C. §300f(1)(C)(ii)).

U.S. Environmental Protection Agency (EPA): The federal agency responsible for implementing the Safe Drinking Water Act, setting national drinking water standards, and overseeing state, local, and tribal implementation of the Act (42 U.S.C. §300f et seq.).

Underground Injection: The subsurface emplacement of fluids by well injection, which can potentially contaminate groundwater sources of drinking water (42 U.S.C. §300h(d)(1)).

Variance: A temporary or permanent exemption from a maximum contaminant level or treatment technique requirement granted by the EPA or a state to a public water system under certain conditions (42 U.S.C. §300g-4).

Water Quality Analysis: The testing of water samples to determine the presence and concentration of various contaminants, as well as other physical, chemical, and biological characteristics of the water (40 C.F.R. §141.23-28).

Wellhead Protection Area: The surface and subsurface area surrounding a water well or wellfield supplying a public water system, through which contaminants are reasonably likely to move toward and reach such water well or wellfield (42 U.S.C. §300h-7(e)).