WasteWater Operator class C exam practice review Latest Update 2025-2026 100 Questions and 100% Verified Correct Answers Guaranteed A+
A colored dye solution is added into the raw wastewater entering a primary settling tank.The dye color was noticeable in the effluent in 15 min and all of the color had passed through the tank in 40 min. What does this indicate?
- Wastewater is passing through the tank too fast for effective settling
- Optimal detention time is being achieved
- This tank has a detention time of 40 min.
D. This tank design has a detention time of 55 min. - CORRECT ANSWER: A.
Wastewater is passing through the tank too fast for effective settling
A decrease in temperature will have what effect on disinfection?
- Require longer contact time
- Require shorter contact time
- Increase rate of disinfection
- Have no effect on disinfection - CORRECT ANSWER: A. Require longer contact time
A good settling sludge would consist of what type of protozoa?
- Rotifers and nematodes
- Amoebas and Flagellates
- Stalked ciliates and mastagoria 1 / 3
D. Free swimmers and stalk ciliates - CORRECT ANSWER: D. Free swimmers and
stalk ciliates
A plant with a flow of 1 MGD should be monitored
- Continuously
- Intermittently
- Daily
D. Every four hours depending on surface load - CORRECT ANSWER: A. Continuously
According to FAC Ch. 62-600, Domestic WasteWater Facilities, your job s an operator during major process breakdowns is to?
- Maintain competent documentation and record keeping
- Report to the DEP within 24 hours after the problem is fixed
- Call the fire department
D. Shut down the plant immediately - CORRECT ANSWER: A. Maintain competent
documentation and record keeping
After removing the roof of the chlorinator storage, building during the summer, the Cl2 stop feeding, what is the cause?
- The CPRV became clogged
- The tank got hotter than the manifold
- The external pressure reducer failed
D. The tank is empty - CORRECT ANSWER: B. The tank got hotter than the manifold
Amperometric titration is used to measure 2 / 3
- Dissolved solids
- Chlorine residual
- Colloids
D. Emulsions - CORRECT ANSWER: B. Chlorine residual
As an operator, how do you control the anaerobic digestion process?
- Microbial population and temperature
- H2S and methane concentration
- Temperature and rate of raw sludge feed
D. Methane and Co2 production - CORRECT ANSWER: C. Temperature and rate of raw
sludge feed
At what pH would disinfection be at its greatest?
- 9
- 7
C. 6.5
D. 5 - CORRECT ANSWER: D. 5
Before operating any piece of equipment what should be done?
- Lock out Tag out (remember, safety first!)
- Read O & M manual
- Read manufacturers manual
- Notify supervisor - CORRECT ANSWER: C. Read manufacturers manual
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