GRADE 2 WATER DISTRIBUTION EXAM TEST WITH
LATEST UPDATED (QUESTIONS AND ANSWERS) ALREADY
PASSED!!
What is static head? Correct Answers The vertical distance between a
reference point to the water surface, when the water is not moving.
How long must water remain stagnant and undisturbed in the pipe before
a first-draw sample is collected for lead and copper analysis? Correct
Answers At least 6 hours
If at least 40 samples per month are collected from a public water
system, what is the minimum percentage of routine/repeat samples that
must test negative for total coliform? Correct Answers 95%
If the water has low pH, what does it indicate? Correct Answers
Corrosive water
What is the purpose of a mechanical seal? Correct Answers Prevents
water leakage from the pump
What could cause a chlorine gas cylinder to frost? Correct Answers Feed
rate is too high
Which chemicals are formed when chlorine gas is injected into water?
Correct Answers Hypochlorous acid and hydrochloric acid
,Which of the following is true about the effectiveness of chlorine? A)
The higher the pH, the better the disinfection of chlorine, B) chlorine is
the most effective at pH=10, C) the lower the pH, the better the
disinfection of chlorine, or D) chlorine is the most effective at pH=12.
Correct Answers C) the lower the pH, the better the disinfection of
chlorine.
What does a high C factor for a pipe indicate? Correct Answers Smooth
pipe interior
What is the disadvantage of having a tree formation in the water
distribution system? Correct Answers Dead-end mains
If chlorine is injected into cold water, how would the cold temperature
affect the effectiveness of chlorine? Correct Answers More contact time
would be required
If a confined space has 20.9% oxygen content, what does this tell you?
Correct Answers Confined space is safe to enter
What could be the problem if an excessive amount of water is leaking
from the stuffing box? Correct Answers Packings may need to be
replaced, or the packing gland may need to be tightened.
What is installed on the suction pipe of a pump to prevent water from
draining out of the pump, and towards the suction pipe? Correct
Answers foot valve
,What problem could arise due to excessive air bubbles in a pipeline?
Correct Answers air pocket forms at the high points
What is formed when chlorine reacts with ammonia? Correct Answers
Chloramine
What is the disadvantage of using ozone for disinfection? Correct
Answers lack of disinfectant residuals
Which water source is the most protected from pathogens? Correct
Answers deep well
What is used to restrict leakage from the impeller discharge to the pump
suction? Correct Answers wear rings
What is trihalomethane? Correct Answers Disinfection by-product
What is the recommended minimum flushing velocity? Correct Answers
2.5 ft/s (5 ft/s preferred)
What is monochloramine? Correct Answers combined chlorine
Which of the following is the most powerful disinfectant? Correct
Answers chlorine
, What is the advantage of a compound meter? Correct Answers It's
capable of measuring a wide range of flow
Which of the following is a positive displacement pump? Correct
Answers piston pump or gear pump
Where is the best place to install a chlorine gas leak warning device (not
the chlorine sensor)? Correct Answers Outside the chlorine gas room
What is one of the purposes of seal water in a pump? Correct Answers
cool and lubricate the packings
What would most likely cause a coupon to lose weight? Correct
Answers corrosive water
Where is the location of the auxiliary valve on a wet-barrel hydrant?
Correct Answers between the hydrant and water main
What is used to control water hammer? Correct Answers surge tank
What would most likely cause back-siphonage in a water main? Correct
Answers broken water main
LATEST UPDATED (QUESTIONS AND ANSWERS) ALREADY
PASSED!!
What is static head? Correct Answers The vertical distance between a
reference point to the water surface, when the water is not moving.
How long must water remain stagnant and undisturbed in the pipe before
a first-draw sample is collected for lead and copper analysis? Correct
Answers At least 6 hours
If at least 40 samples per month are collected from a public water
system, what is the minimum percentage of routine/repeat samples that
must test negative for total coliform? Correct Answers 95%
If the water has low pH, what does it indicate? Correct Answers
Corrosive water
What is the purpose of a mechanical seal? Correct Answers Prevents
water leakage from the pump
What could cause a chlorine gas cylinder to frost? Correct Answers Feed
rate is too high
Which chemicals are formed when chlorine gas is injected into water?
Correct Answers Hypochlorous acid and hydrochloric acid
,Which of the following is true about the effectiveness of chlorine? A)
The higher the pH, the better the disinfection of chlorine, B) chlorine is
the most effective at pH=10, C) the lower the pH, the better the
disinfection of chlorine, or D) chlorine is the most effective at pH=12.
Correct Answers C) the lower the pH, the better the disinfection of
chlorine.
What does a high C factor for a pipe indicate? Correct Answers Smooth
pipe interior
What is the disadvantage of having a tree formation in the water
distribution system? Correct Answers Dead-end mains
If chlorine is injected into cold water, how would the cold temperature
affect the effectiveness of chlorine? Correct Answers More contact time
would be required
If a confined space has 20.9% oxygen content, what does this tell you?
Correct Answers Confined space is safe to enter
What could be the problem if an excessive amount of water is leaking
from the stuffing box? Correct Answers Packings may need to be
replaced, or the packing gland may need to be tightened.
What is installed on the suction pipe of a pump to prevent water from
draining out of the pump, and towards the suction pipe? Correct
Answers foot valve
,What problem could arise due to excessive air bubbles in a pipeline?
Correct Answers air pocket forms at the high points
What is formed when chlorine reacts with ammonia? Correct Answers
Chloramine
What is the disadvantage of using ozone for disinfection? Correct
Answers lack of disinfectant residuals
Which water source is the most protected from pathogens? Correct
Answers deep well
What is used to restrict leakage from the impeller discharge to the pump
suction? Correct Answers wear rings
What is trihalomethane? Correct Answers Disinfection by-product
What is the recommended minimum flushing velocity? Correct Answers
2.5 ft/s (5 ft/s preferred)
What is monochloramine? Correct Answers combined chlorine
Which of the following is the most powerful disinfectant? Correct
Answers chlorine
, What is the advantage of a compound meter? Correct Answers It's
capable of measuring a wide range of flow
Which of the following is a positive displacement pump? Correct
Answers piston pump or gear pump
Where is the best place to install a chlorine gas leak warning device (not
the chlorine sensor)? Correct Answers Outside the chlorine gas room
What is one of the purposes of seal water in a pump? Correct Answers
cool and lubricate the packings
What would most likely cause a coupon to lose weight? Correct
Answers corrosive water
Where is the location of the auxiliary valve on a wet-barrel hydrant?
Correct Answers between the hydrant and water main
What is used to control water hammer? Correct Answers surge tank
What would most likely cause back-siphonage in a water main? Correct
Answers broken water main
