Glossary
Water Treatment Plant Operator Terms & Vocabulary
15 essential water treatment plant operator terms with plain-English definitions: the vocabulary you’ll hear in training and on day one.
Key water treatment plant operator vocabulary
These 15 terms come up constantly in water treatment plant operator training, on the job and in interviews. Knowing them helps you follow instructions, document accurately and sound prepared.
- Activated sludge
- A wastewater process using microorganisms to break down organic matter.
- Backwash
- Reversing flow to clean a filter.
- BOD
- Biochemical oxygen demand: a measure of organic pollution.
- Chlorine residual
- Chlorine remaining in water to keep it disinfected in the distribution system.
- Clarifier
- A tank where solids settle out of water or wastewater.
- Coagulation
- Adding chemicals that make small particles clump together.
- Disinfection
- Killing pathogens, often with chlorine or UV light.
- Filtration
- Passing water through media to remove remaining particles.
- Flocculation
- Gentle mixing that helps clumps (floc) grow larger.
- Lift station
- A pump station that moves wastewater uphill.
- MCL
- Maximum contaminant level: the legal limit for a contaminant in drinking water.
- NPDES permit
- The permit limiting what a wastewater plant may discharge.
- Sedimentation
- Letting floc settle out of water in basins.
- TSS
- Total suspended solids in water.
- Turbidity (NTU)
- Cloudiness of water, measured in nephelometric turbidity units.
Practice these terms
Test yourself with the free Water Treatment Plant Operator practice test: it includes vocabulary questions built from this list. For a complete course, see Water Treatment Plant Operator training.
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