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 Z5 random terms from our glossary
endocrine effects (EN-doe-krin)
An altering of the organs in the human body responsible for secreting hormones into the bloodstream. Endocrine glands include the thyroid gland, the pancreas, and the adrenal glands.
carcinogen (kar-SIN-o-jen)
Any substance that tends to produce cancer in an organism.
offset joint
A pipe joint that is not exactly in line and centered. Also see drop joint and vertical offset.
sludge volume index (SVI)
A calculation that indicates the tendency of activated sludge solids (aerated solids) to thicken or to become concentrated during the sedimentation/thickening process. SVI is calculated in the following manner:
- allow a mixed liquor sample from the aeration basin to settle for 30 minutes;
- determine the suspended solids concentration for a sample of the same mixed liquor;
- calculate SVI by dividing the measured (or observed) wet volume (mL/L) of the settled sludge by the dry weight concentration of MLSS in grams/L.
CSO (combined sewer overflow)
Wastewater that flows out of a combined collection system (or lift station) as a result of flows exceeding the hydraulic capacity of the system or stoppages in the pipes. CSOs exceeding the hydraulic capacity usually occur during periods 16 Glossary of heavy precipitation or high levels of runoff from snow melt or other runoff sources.
