Test 3 – Wastewater Treatment Operator Certification Practice Exam (Updated 2025) | Verified Questions & Answers

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Test 3 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




The typical suspended solids removal rate in the primary clarifier is 5 to 10%. - CORRECT
ANSWER False



QUESTION :Over-greasing a pump motor can lead to damage. - CORRECT ANSWER
True



QUESTION :A healthy digester gas consists mostly of hydrogen sulfide. - CORRECT
ANSWER False



QUESTION :Coliform results are reported as MPN/100 mL. - CORRECT ANSWER True



QUESTION :Increased concentrations of volatile acids and decreased alkalinity are signs that
the anaerobic digestion is in an ideal state. - CORRECT ANSWER False



QUESTION :Breakpoint chlorination is the addition of chlorine to wastewater until the chlorine
demand has been met. - CORRECT ANSWER True



QUESTION :Zero calibration accuracy for DO probes and meters should be checked with an
absolute zero solution (sodium sulfite). - CORRECT ANSWER True



QUESTION :Temperature, pH, and dissolved oxygen do not have to be analyzed immediately

because they can be preserved. - CORRECT ANSWER False




2026 2027 GRADED A+

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QUESTION :Sterilization is the goal of most wastewater treatment plants. - CORRECT
ANSWER False



QUESTION :One of the most common types of package plants is extended aeration. -
CORRECT ANSWER True


QUESTION :NDES permits are issued by the EPA or the state. - CORRECT ANSWER
True



QUESTION :Hypochlorination will raise the pH of wastewater being treated. - CORRECT
ANSWER True



QUESTION :Denitrification does not cause sludge to rise in a secondary clarifier. - CORRECT
ANSWER False



QUESTION :The sludge digester can be either aerobic or anaerobic - CORRECT ANSWER
True


QUESTION :In order to protect your family from infectious disease, you should not wear your
work clothes home. - CORRECT ANSWER True



QUESTION :One application of centrifugal pumps is to lift raw wastewater. - CORRECT
ANSWER True



QUESTION :BOD and suspended solids are measured using grab samples. - CORRECT
ANSWER False



QUESTION :Algae uses carbon dioxide in the pond to produce free oxygen for the aerobic
bacteria. - CORRECT ANSWER True



QUESTION :The purpose of a scraper in a clarifier is to collect the settled wastewater flowing
over the weirs and convey it from the clarifier. - CORRECT ANSWER False


2026 2027 GRADED A+