WasteWater Operator Class C Exam
Practice Review 2025/2026 Exam
Questions and Answers | 100% Solved
When Chlorine is combined with water what type of pipe should be used?
A. Ductile iron
B. Asbestos concrete
C. PVC
D. Carbon Steel - 🧠 ANSWER ✔✔C. PVC
A good settling sludge would consist of what type of protozoa?
A. Rotifers and nematodes
B. Amoebas and Flagellates
C. Stalked ciliates and mastagoria
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,D. Free swimmers and stalk ciliates - 🧠 ANSWER ✔✔D. Free swimmers
and stalk ciliates
What is Phenolphylein used for in titration
A. Oxidizer
B. Indicator
C. Acid reducer to lower pH
D. Applicator - 🧠 ANSWER ✔✔B. Indicator
Your plant has an influent of 220 BOD and 163 TSS, and an effluent of 10
BOD, and 6 TSS. What is the BOD removal efficiency in your plant?
A. 92%
B. 94%
C. 95%
D. 96% - 🧠 ANSWER ✔✔C. 95%
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,You suspect your anaerobic digester is going sour. What is the best way to
verify its condition?
A. pH
B. Foam type
C. VA/ALK ratio
D. DO - 🧠 ANSWER ✔✔C. VA/ALK ratio
Before operating any piece of equipment what should be done?
A. Lock out Tag out (remember, safety first!)
B. Read O & M manual
C. Read manufacturers manual
D. Notify supervisor - 🧠 ANSWER ✔✔C. Read manufacturers manual
Detritus is noticed in your grit channel. What is the problem?
A. Velocity too fast with short D/T
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, B. Velocity too low with long D/T
C. Short circuiting
D. Density currents - 🧠 ANSWER ✔✔B. Velocity too low with long D/T
What is considered normal operation of an aerobic digester?
A. Fill react
B. Skim off foam when needed
C. Settle and Decant as needed
D. Feed only during low flow or constant when the sun is out - 🧠 ANSWER
✔✔C. Settle and Decant as needed
A plant with a flow of 1 MGD should be monitored
A. Continuously
B. Intermittently
C. Daily
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
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PRIVACY STATEMENT. ALL RIGHTS RESERVED
Practice Review 2025/2026 Exam
Questions and Answers | 100% Solved
When Chlorine is combined with water what type of pipe should be used?
A. Ductile iron
B. Asbestos concrete
C. PVC
D. Carbon Steel - 🧠 ANSWER ✔✔C. PVC
A good settling sludge would consist of what type of protozoa?
A. Rotifers and nematodes
B. Amoebas and Flagellates
C. Stalked ciliates and mastagoria
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
1
PRIVACY STATEMENT. ALL RIGHTS RESERVED
,D. Free swimmers and stalk ciliates - 🧠 ANSWER ✔✔D. Free swimmers
and stalk ciliates
What is Phenolphylein used for in titration
A. Oxidizer
B. Indicator
C. Acid reducer to lower pH
D. Applicator - 🧠 ANSWER ✔✔B. Indicator
Your plant has an influent of 220 BOD and 163 TSS, and an effluent of 10
BOD, and 6 TSS. What is the BOD removal efficiency in your plant?
A. 92%
B. 94%
C. 95%
D. 96% - 🧠 ANSWER ✔✔C. 95%
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
2
PRIVACY STATEMENT. ALL RIGHTS RESERVED
,You suspect your anaerobic digester is going sour. What is the best way to
verify its condition?
A. pH
B. Foam type
C. VA/ALK ratio
D. DO - 🧠 ANSWER ✔✔C. VA/ALK ratio
Before operating any piece of equipment what should be done?
A. Lock out Tag out (remember, safety first!)
B. Read O & M manual
C. Read manufacturers manual
D. Notify supervisor - 🧠 ANSWER ✔✔C. Read manufacturers manual
Detritus is noticed in your grit channel. What is the problem?
A. Velocity too fast with short D/T
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
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PRIVACY STATEMENT. ALL RIGHTS RESERVED
, B. Velocity too low with long D/T
C. Short circuiting
D. Density currents - 🧠 ANSWER ✔✔B. Velocity too low with long D/T
What is considered normal operation of an aerobic digester?
A. Fill react
B. Skim off foam when needed
C. Settle and Decant as needed
D. Feed only during low flow or constant when the sun is out - 🧠 ANSWER
✔✔C. Settle and Decant as needed
A plant with a flow of 1 MGD should be monitored
A. Continuously
B. Intermittently
C. Daily
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
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PRIVACY STATEMENT. ALL RIGHTS RESERVED
