Glossary & Lingo

1 pascal = 1 Newton/m2

Organisms, including bacteria, viruses, or cysts, capable of causing diseases (giardiasis, cryptosporidiosis, typhoid, cholera, dysentery) in a host (such as a person). There are many types of organisms that do NOT cause disease. These organisms are called non-pathogenic.

The maximum momentary load placed on a water treatment plant, pumping station, or distribution system. This demand is usually the maximum average load in one hour or less but may be specified as the instantaneous load or the load during some other short time period.

A type of flow that occurs in tanks, basins, or reactors when a slug of water moves through a tank without ever dispersing or mixing with the rest of the water flowing through the tank.

Water that requires no further treatment and is safe for public consumption. 

An Imperial unit of measurement used to express the volume or weight of a material dissolved in a water solution. PPM is equivalent to milligrams per litre (mg/L) which is the preferred unit for measurement. 

A force acting on a given area. The pressure is calculated by dividing the force by the area over which it is acting. The metric unit of pressure is the Pascal (kPa) and the imperial unit is pound per square inch (psi).

Instrument used to measure pressure.

A water tank that is under pressure. Used in water systems to maintain pressure and provide storage.

Single-celled microorganisms with a more complex physiology than viruses and bacteria. Giardia and Cryptosporidium are the two main protozoa of concern. 

Pound per Square Inch: An imperial unit of pressure. 1 psi = 1 pound per square inch.

A supplier or provider of water.