Free practice test

Water Treatment Plant Operator Practice Test

Check what you know about the water treatment plant operator job with 15 free questions and instant explanations.

Updated By the Career Education Institute Curriculum Team
About this practice test

15 multiple-choice questions on water treatment plant operator knowledge, safety and vocabulary. Submit to see your score and explanations, or open any question’s answer as you go. Nothing is saved or shared.

Question 1 of 15Which step comes first in conventional drinking water treatment?
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Answer: Coagulation. Coagulation starts the particle-removal process.

Question 2 of 15Turbidity measures:
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Answer: Cloudiness. Turbidity is cloudiness, measured in NTU.

Question 3 of 15Why maintain a chlorine residual?
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Answer: To keep water disinfected in the distribution system. Residual protects water after it leaves the plant.

Question 4 of 15What does BOD measure?
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Answer: Organic pollution. BOD indicates organic matter.

Question 5 of 15Backwashing a filter:
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Answer: Cleans the filter media. Reverse flow cleans the media.

Question 6 of 15Which term matches this definition: “Passing water through media to remove remaining particles.”
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Answer: Filtration. Filtration: Passing water through media to remove remaining particles.

Question 7 of 15What does “Sedimentation” mean?
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Answer: Letting floc settle out of water in basins.. Sedimentation: Letting floc settle out of water in basins.

Question 8 of 15Which term matches this definition: “Chlorine remaining in water to keep it disinfected in the distribution system.”
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Answer: Chlorine residual. Chlorine residual: Chlorine remaining in water to keep it disinfected in the distribution system.

Question 9 of 15What does “Backwash” mean?
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Answer: Reversing flow to clean a filter.. Backwash: Reversing flow to clean a filter.

Question 10 of 15Which term matches this definition: “Adding chemicals that make small particles clump together.”
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Answer: Coagulation. Coagulation: Adding chemicals that make small particles clump together.

Question 11 of 15What does “NPDES permit” mean?
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Answer: The permit limiting what a wastewater plant may discharge.. NPDES permit: The permit limiting what a wastewater plant may discharge.

Question 12 of 15Which term matches this definition: “Gentle mixing that helps clumps (floc) grow larger.”
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Answer: Flocculation. Flocculation: Gentle mixing that helps clumps (floc) grow larger.

Question 13 of 15What does “Activated sludge” mean?
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Answer: A wastewater process using microorganisms to break down organic matter.. Activated sludge: A wastewater process using microorganisms to break down organic matter.

Question 14 of 15Which term matches this definition: “Cloudiness of water, measured in nephelometric turbidity units.”
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Answer: Turbidity (NTU). Turbidity (NTU): Cloudiness of water, measured in nephelometric turbidity units.

Question 15 of 15What does “Clarifier” mean?
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Answer: A tank where solids settle out of water or wastewater.. Clarifier: A tank where solids settle out of water or wastewater.

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