Glossary of Water and Wastewater Terms

A B C D E F G H I J K L M N O P Q R S T U V W Y Z Symbols and Numbers

5 random terms from our glossary

Amperometric Titration (am-purr-o-MET-rick)

A means of measuring concentrations of certain substances in water (such as strong oxidizers) based on the electric current that flows during a chemical reaction. Also see TITRATE.


Any incident in which a sewer is partially or completely blocked, causing a backup, a service interruption, or an overflow. Also called stoppage.

Positive Pressure

A positive pressure is a pressure greater than atmospheric. It is measured as pounds per square inch (psi) or as inches of water column. A negative pressure (vacuum) is less than atmospheric and is sometimes measured in inches of mercury. In the metric system, pressures are measured in kg/sq m, kg/sq cm, or pascals (1 psi = 6,895 Pa = 6.895 kN/sq m).

Megger (from megohm)

An instrument used for checking the insulation resistance on motors, feeders, bus bar systems, grounds, and branch circuit wiring. A megger reads in millions of ohms. Also see MEG.

Aeration Liquor (air-a-shun)

Mixed liquor. The contents of the aeration tank, including living organisms and material carried into the tank by either untreated wastewater or primary effluent.