Test 4 – Wastewater Treatment Operator Certification Practice Exam (Updated 2025) | Verified Questions & Answers

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Test 4 Wastewater treatment operator certification practice (NEW UPDATED
VERSION) LATEST ACTUAL EXAM QUESTIONS AND CORRECT ANSWERS (VERIFIED
QUESTIONS AND ANSWERS) | GUARANTEED PASS A+ UPDATED THIS YEAR


1 mg/l is the same as 1 part per billion (ppb)


True or False - CORRECT ANSWER False (v.1 pg 468)


QUESTION :A SCADA system is capable of monitoring and controlling equipment from a
remote location


True or False - CORRECT ANSWER True (v.2 pg 627)


QUESTION :A Discharge Monitoring Report is typically submitted to the regulatory agency on a
daily basis


True or False - CORRECT ANSWER False


QUESTION :A mechanical seal is used to prevent leaks between the pump casing and shaft.


True or False - CORRECT ANSWER True (v.2 pg 356)


QUESTION :Alkalinity is the capacity of a liquid to neutralize a base.


True or False - CORRECT ANSWER False (v.2 pg 813)


QUESTION :Typical mixed liquor suspended solids concentration is 1,000 to 4,500 mg/l.


True or False - CORRECT ANSWER True (v.2 pg 54)




2026 2027 GRADED A+

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QUESTION :Turbidity is caused by suspended matters.


True or False - CORRECT ANSWER True (v.2 pg 606)


QUESTION :Algae is not essential to the successful operation of both aerobic and facultative
ponds.


True or False - CORRECT ANSWER False (v.1 pg 299)


QUESTION :The addition of acid and CO2 will lower the pH of wastewater.


True or False - CORRECT ANSWER True (v.1 pg 299)


QUESTION :Hydrogen sulfide will deteriorate concrete structures.


True or False - CORRECT ANSWER True (v.1 pg 20)


QUESTION :The higher the pH, the better the disinfection - CORRECT ANSWER False (v.1
pg 352)


QUESTION :Maintain a dissolved oxygen concentration of 12 to 14 mg/l in the aeration tank.


True or False - CORRECT ANSWER False (v.2 pg 53)


QUESTION :When the velocity of the wastewater in a clarifier is greater in some sections than
others, it will lead to short-circuiting.


True or False - CORRECT ANSWER True (v.1 pg 135)


QUESTION :The F/M ratio will decrease when the microorganism population in the aeration
tank increases.



2026 2027 GRADED A+

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True or False - CORRECT ANSWER True (v.2 pg 16)


QUESTION :Algae growth will be faster when there is less sunlight.


True or False - CORRECT ANSWER False (v.1 pg 309)


QUESTION :The higher the temperature, the more rapid the rate of disinfection.


True or False - CORRECT ANSWER True (v.1 pg 352)


QUESTION :One of the benefits of recirculation for a trickling filter is that it decreases the
contact time of the wastewater with the biological film.


True or False - CORRECT ANSWER False (v.1 pg 175)


QUESTION :Maintaining a constant temperature in an anaerobic digester is one way to prevent
foaming from recurring.


True or False - CORRECT ANSWER True (v.2 pg 187)


QUESTION :Preventative maintenance is a proactive, programmed, and systematic approach
to maintenance.


True or False - CORRECT ANSWER True (v.2 pg 718)


QUESTION :Abnormal operation in a pond will not occur if it is overloaded with BOD.


True or False - CORRECT ANSWER False (v.1 pg 307)


QUESTION :Anaerobic decomposition of sewage will release hydrogen sulfide.



2026 2027 GRADED A+