Glossary of Water and Wastewater Terms

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5 random terms from our glossary

groundwater

Subsurface water in the saturation zone from which wells and springs are fed. In a strict sense the term applies only to water below the water table. Also called phreatic water and plerotic water.

recycled water

Water that is used more than once before being passed back into the water cycle. Often the water must be treated to make it suitable for the next use. Also see water reuse and reclaimed water.

Hazard Communication Standard (HCS)

The Occupational Safety and Health Administration (OSHA) mandate, 29 CFR 1910.1200, states that companies producing and using hazardous materials must provide employees with information and training on the proper handling and use of these materials. This standard requires chemical manufacturers and importers to evaluate the hazards of the chemicals they produce or import, and prepare labels and safety data sheets to convey the hazard information to their downstream customers; and all employers with hazardous chemicals in their workplaces to provide labels, safety data sheets, and training to their exposed workers. The HCS is intended to be consistent with the provisions of the United Nations Globally Harmonized System of Classification and Labeling of Chemicals (GHS), Revision 3.

pneumatic ejector (noo-MAT-tik ee-JECK-tor)

A device for raising wastewater, sludge, or other liquid by compressed air. The liquid is alternately admitted through an inward-swinging check valve into the bottom of an airtight pot. When the pot is filled, compressed air is applied to the top of the liquid. The compressed air forces the inlet valve closed and forces the liquid in the pot through an outward-swinging check valve, thus emptying the pot.

available expansion

The vertical distance from the sand surface to the underside of a trough in a sand filter. Also called freeboard.