Basic Wastewater Operator Practice Exam
(Latest ) Questions with
Answers 100% Correct {Grade A}
What is the most common type of activated sludge package plants?
a. extended aeration
b. sequential batch reactor
c. oxidation ditch
d. bardenpho - Correct answer a. extended aeration
What is the most appropriate method of reducing the F:M ratio?
A. increase wasting
b. decrease wasting
c. reduce BOD from influent flow
D. add polymer to RAS to increase settling - Correct answer b. decrease wasting
,An operator notices a portion of the aeration tank with large bubbles rising up. What is
the most likely problem?
a. equal air distribution
b. unequal air distribution caused by a blown/clogged diffuser
c. normal operation
d. reason to believe the air filter in the blower is clogged - Correct answer b. unequal
air distribution caused by a blown diffuser
What is suction lift?
a. a team approach to lifting heavy objects
b. the pressure on the suction side of the pump
c. the measurement of liquid pressure at the pump
d. the measure of how bad your workers lift heavy objects - Correct answer b. the
pressure on the suction side of the pump
,The primary effluent to a RBC system is 350 mg/L BOD. The primary unit removes 83%
the secondary unit removes 50% and the final unit removes 25%. What is the BOD
leaving the final unit of the RBC train?
A. 290 mg/L
b. 60 mg/L
c. 30 mg/L
d. 22.5 mg/L - Correct answer d. 22.5 mg/L
The influent to the treatment plant is septic. it is determined that it is coming from a lift
station upstream from the plant. What should the operator do?
A. decrease the lag time for pump operation by moving the floats closer together
b. add pH adjuster to the influent flow
c. install larger capacity pumps in the lift stations
d. the her nothing you can do to correct this problem - Correct answer A. decrease the
lag time for pump operation by moving the floats closer together
, What is the purpose of amber storage bottles?
A. the color is pretty
b. they are cheaper
c. to protect chemicals that are sensitive to light
d. so you can not see what is inside the container - Correct answer c. to protect
chemicals that are sensitive to light
Calculate SRT
Given: MLSS = 2400 mg/L
Aeration basin volume = 35,000 gallons = 0.0350 MG
WAS concentration = 3500 mg/L
WAS flow rate = 0.001 MGD
A. 6 hours
b. 6 days
c. 24 hours
d. 24 days - Correct answer d. 24 days
(Latest ) Questions with
Answers 100% Correct {Grade A}
What is the most common type of activated sludge package plants?
a. extended aeration
b. sequential batch reactor
c. oxidation ditch
d. bardenpho - Correct answer a. extended aeration
What is the most appropriate method of reducing the F:M ratio?
A. increase wasting
b. decrease wasting
c. reduce BOD from influent flow
D. add polymer to RAS to increase settling - Correct answer b. decrease wasting
,An operator notices a portion of the aeration tank with large bubbles rising up. What is
the most likely problem?
a. equal air distribution
b. unequal air distribution caused by a blown/clogged diffuser
c. normal operation
d. reason to believe the air filter in the blower is clogged - Correct answer b. unequal
air distribution caused by a blown diffuser
What is suction lift?
a. a team approach to lifting heavy objects
b. the pressure on the suction side of the pump
c. the measurement of liquid pressure at the pump
d. the measure of how bad your workers lift heavy objects - Correct answer b. the
pressure on the suction side of the pump
,The primary effluent to a RBC system is 350 mg/L BOD. The primary unit removes 83%
the secondary unit removes 50% and the final unit removes 25%. What is the BOD
leaving the final unit of the RBC train?
A. 290 mg/L
b. 60 mg/L
c. 30 mg/L
d. 22.5 mg/L - Correct answer d. 22.5 mg/L
The influent to the treatment plant is septic. it is determined that it is coming from a lift
station upstream from the plant. What should the operator do?
A. decrease the lag time for pump operation by moving the floats closer together
b. add pH adjuster to the influent flow
c. install larger capacity pumps in the lift stations
d. the her nothing you can do to correct this problem - Correct answer A. decrease the
lag time for pump operation by moving the floats closer together
, What is the purpose of amber storage bottles?
A. the color is pretty
b. they are cheaper
c. to protect chemicals that are sensitive to light
d. so you can not see what is inside the container - Correct answer c. to protect
chemicals that are sensitive to light
Calculate SRT
Given: MLSS = 2400 mg/L
Aeration basin volume = 35,000 gallons = 0.0350 MG
WAS concentration = 3500 mg/L
WAS flow rate = 0.001 MGD
A. 6 hours
b. 6 days
c. 24 hours
d. 24 days - Correct answer d. 24 days
