Glossary of Water and Wastewater Terms

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5 random terms from our glossary

outfall

The point, location, or structure where wastewater or drainage discharges from a collection pipe, drain, or other conduit. Also, the conduit leading to the final discharge point or area. Also see outfall sewer.

pressure main

See force main.

oxidizing agent

Any substance, such as oxygen (O₂) or chlorine (Cl₂), that will readily add (take on) electrons. When oxygen or chlorine is added to water or wastewater, organic substances are oxidized. These oxidized organic substances are more stable and less likely to give off odors or to contain disease-causing bacteria. The opposite is a reducing agent.

chemical precipitation

1. Precipitation induced by the addition of chemicals.
2. The process of softening water by the addition of lime or lime and soda ash as the precipitants.

scale

(1) Deposits of mineral salts or bacteria that build up on surfaces, such as membranes or the inside of pipes. In extreme growth circumstances, scale interferes with water and wastewater flow and treatment. (2) The marked plate against which an indicator or recorder reads, usually the same as the range of the measuring system. Also see range.