WASTEWATER PRACTICE EXAM 4 CORE
WATER TREATMENT PROCESSES AND SYSTEM
OPERATIONS REVIEW 2026
◉ How do you calibrate a chemical feed pump?
A. by measuring the pump output
B. using the SWAG method
C. jar test
D. with a microscope.
Answer: A. by measuring the pump output
◉ What is the chemical formula for sulfuric acid?
a. HNO3
b. HCl
c. NaOH
d. H2SO4.
Answer: d. H2SO4
,◉ What is the most common type of activated sludge package
plants?
a. extended aeration
b. sequential batch reactor
c. oxidation ditch
d. bardenpho.
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.
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.
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.
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.
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.
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.
Answer: c. to protect chemicals that are sensitive to light
◉ Calculate SRT
Given: MLSS = 2400 mg/L
WATER TREATMENT PROCESSES AND SYSTEM
OPERATIONS REVIEW 2026
◉ How do you calibrate a chemical feed pump?
A. by measuring the pump output
B. using the SWAG method
C. jar test
D. with a microscope.
Answer: A. by measuring the pump output
◉ What is the chemical formula for sulfuric acid?
a. HNO3
b. HCl
c. NaOH
d. H2SO4.
Answer: d. H2SO4
,◉ What is the most common type of activated sludge package
plants?
a. extended aeration
b. sequential batch reactor
c. oxidation ditch
d. bardenpho.
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.
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.
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.
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.
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.
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.
Answer: c. to protect chemicals that are sensitive to light
◉ Calculate SRT
Given: MLSS = 2400 mg/L
