Glossary of Water and Wastewater Terms

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5 random terms from our glossary

combined wastewater

A mixture of stormwater or surface water runoff and other wastewater, such as domestic or industrial wastewater.

molecular oxygen

The oxygen molecule, O₂, that is not combined with another element to form a compound.

bench

The bottom of the inside of a manhole. Also called apron, base, or shelf.

decant water (de-KANT)

Water that has separated from sludge and is removed from the layer of water above the sludge.

Manning's Formula

A mathematical formula for calculating wastewater flows in sewers.

• Q means flow in cubic feet per second (CFS) (cubic meters per second (m³/s)).
• n means the Manning pipe or channel roughness factor.
• A means the cross-sectional area of the flow in square feet (sq ft) (square meters (m²)).
• R means the hydraulic radius in feet (meters) where R equals A/P. P is the wetted perimeter of the channel or pipe in feet (meters).
• S means the slope of the channel or energy grade line in feet per foot (ft/ft) (meters per meter (m/m)).