WASTEWATER OPERATOR CLASS C EXAMS SET 2026 PRACTICE QUESTIONS AND ANSWERS FULL SOLUTION VIEW AHEAD

WASTEWATER OPERATOR CLASS C EXAMS
SET 2026 PRACTICE QUESTIONS AND
ANSWERS FULL SOLUTION VIEW AHEAD

●● detention time.
Answer: The time wastewater spends in a treatment facility, calculated
as volume divided by flow rate.


●● 0.5 MGD.
Answer: A flow rate equivalent to 0.5 million gallons per day.


●● chlorination.
Answer: The process of adding chlorine to wastewater to kill pathogens.


●● dechlorinate.
Answer: The process of removing chlorine from wastewater effluent.


●● minimum oxygen level for confined space.
Answer: 19.5% is considered the safe minimum oxygen level for entry.


●● safety equipment for confined space.

, Answer: A tripod and harness must always be used when entering a
confined space.


●● Illinois EPA.
Answer: The agency that administers wastewater operator certification
in Illinois.


●● trickling filter.
Answer: A common type of wastewater treatment process used in small
communities.


●● aerobic zone in facultative lagoon.
Answer: The primary purpose is nitrification.


●● pump delivery rate.
Answer: A pump delivering 450 gallons per minute will deliver 108,000
gallons in 4 hours.


●● primary purpose of chlorination.
Answer: To kill pathogens in wastewater treatment.


●● chemical used to dechlorinate.