2024 WATER OPERATOR CLASS 3-
PRACTICE TEST EXAM QUESTIONS
WITH CORRECT ANSWERS
Two ways to aid in backwashing a rapid sand filter are: - CORRECT-
ANSWERSMechanical surface wash and air wash.
Activated carbon works on the principal of: - CORRECT-ANSWERSAdsorption
Turbidity and GWUDISW rules and regulations fall under the: - CORRECT-
ANSWERSSurface Water Treatment Rule
The MCL for turbidity is: - CORRECT-ANSWERS.3 NTU's or lower 95% of the
time
Rapid sand filters remove: - CORRECT-ANSWERSParticles
Calcium carbonate for corrosion should be applied: - CORRECT-ANSWERSJust
after the filter
If a gas chlorine cylinder is leaking, it will leak slower if it leaks: - CORRECT-
ANSWERSGas
An instrument used to detect a breakdown in the internal windings of an
electric motor. - CORRECT-ANSWERSMegger
Tubes are sometimes located in the: - CORRECT-ANSWERSSettling basin
To reduce the size of the floc, you sould: - CORRECT-ANSWERSSpeed up the
flocculator
If you notice fly larvae (blood worms) in your water supply, what is the first
thing you should start looking at as the problem? - CORRECT-ANSWERSThe
condition of the screens on your vents and overflows
A ladder should extend how far above the structure that it accesses? -
CORRECT-ANSWERS3 ft
Any chemical you place into your water must have this approval: - CORRECT-
ANSWERSANSI/NSF 60 approval
, Any discharge from your water plant should be permitted by: - CORRECT-
ANSWERSLDEQ
Polymer is short for: - CORRECT-ANSWERSPolyelectrolytes
The first step you should take when working on a pump is: - CORRECT-
ANSWERSLock out tag out
A rotten egg odor in water indicates what? - CORRECT-ANSWERSHydrogen
sulfide
What is the desired amount of fluoride in water? - CORRECT-ANSWERS1 ppm
Sodium Fluoride and Hydrofluosilicic acid are two chemicals us to do what? -
CORRECT-ANSWERSFluoridate water
What is alum and ferric chloride used for? - CORRECT-ANSWERSCoagulants
How high should a well casing extend above ground level? - CORRECT-
ANSWERS12 inches
How high should a vent extend above ground level? - CORRECT-ANSWERS24
inches
The secondary standard for pH in potable water is: - CORRECT-ANSWERS6.5 -
8.5
MCL for TTHM's - CORRECT-ANSWERS0.08 ppm
MCL for HAA5's - CORRECT-ANSWERS0.06 ppm
MCL for Arsenic - CORRECT-ANSWERS0.01 ppm
MCL for Lead - CORRECT-ANSWERS0.015 ppm
Turbidity meter must be calibrated every: - CORRECT-ANSWERS90 days
MCL for turbidity is - CORRECT-ANSWERSLess than 0.3 for 95% of the time.
pH meters must be calibrated using - CORRECT-ANSWERS2 buffers
A grassy of fishy taste in reservoir water indicates - CORRECT-
ANSWERSAlgae blooms
PRACTICE TEST EXAM QUESTIONS
WITH CORRECT ANSWERS
Two ways to aid in backwashing a rapid sand filter are: - CORRECT-
ANSWERSMechanical surface wash and air wash.
Activated carbon works on the principal of: - CORRECT-ANSWERSAdsorption
Turbidity and GWUDISW rules and regulations fall under the: - CORRECT-
ANSWERSSurface Water Treatment Rule
The MCL for turbidity is: - CORRECT-ANSWERS.3 NTU's or lower 95% of the
time
Rapid sand filters remove: - CORRECT-ANSWERSParticles
Calcium carbonate for corrosion should be applied: - CORRECT-ANSWERSJust
after the filter
If a gas chlorine cylinder is leaking, it will leak slower if it leaks: - CORRECT-
ANSWERSGas
An instrument used to detect a breakdown in the internal windings of an
electric motor. - CORRECT-ANSWERSMegger
Tubes are sometimes located in the: - CORRECT-ANSWERSSettling basin
To reduce the size of the floc, you sould: - CORRECT-ANSWERSSpeed up the
flocculator
If you notice fly larvae (blood worms) in your water supply, what is the first
thing you should start looking at as the problem? - CORRECT-ANSWERSThe
condition of the screens on your vents and overflows
A ladder should extend how far above the structure that it accesses? -
CORRECT-ANSWERS3 ft
Any chemical you place into your water must have this approval: - CORRECT-
ANSWERSANSI/NSF 60 approval
, Any discharge from your water plant should be permitted by: - CORRECT-
ANSWERSLDEQ
Polymer is short for: - CORRECT-ANSWERSPolyelectrolytes
The first step you should take when working on a pump is: - CORRECT-
ANSWERSLock out tag out
A rotten egg odor in water indicates what? - CORRECT-ANSWERSHydrogen
sulfide
What is the desired amount of fluoride in water? - CORRECT-ANSWERS1 ppm
Sodium Fluoride and Hydrofluosilicic acid are two chemicals us to do what? -
CORRECT-ANSWERSFluoridate water
What is alum and ferric chloride used for? - CORRECT-ANSWERSCoagulants
How high should a well casing extend above ground level? - CORRECT-
ANSWERS12 inches
How high should a vent extend above ground level? - CORRECT-ANSWERS24
inches
The secondary standard for pH in potable water is: - CORRECT-ANSWERS6.5 -
8.5
MCL for TTHM's - CORRECT-ANSWERS0.08 ppm
MCL for HAA5's - CORRECT-ANSWERS0.06 ppm
MCL for Arsenic - CORRECT-ANSWERS0.01 ppm
MCL for Lead - CORRECT-ANSWERS0.015 ppm
Turbidity meter must be calibrated every: - CORRECT-ANSWERS90 days
MCL for turbidity is - CORRECT-ANSWERSLess than 0.3 for 95% of the time.
pH meters must be calibrated using - CORRECT-ANSWERS2 buffers
A grassy of fishy taste in reservoir water indicates - CORRECT-
ANSWERSAlgae blooms
