LEVEL 1 WATER DISTRIBUTION PRACTICE TEST QUESTIONS AND ANSWERS ALREADY GRADED A+. 100%
VERIFIED SOLUTIONS | UPDATED PER LATEST GUIDELINES | GRADED A+...
Question 1
What is the primary purpose of a water distribution system?
A. To treat wastewater for reuse
B. To deliver potable water to consumers at adequate pressure and quantity
C. To generate electricity
D. To store rainwater only
🟢 Correct Answer:
B. To deliver potable water to consumers at adequate pressure and quantity
🔴 RATIONALE:
A water distribution system transports treated water from the source or treatment plant to homes, businesses,
and hydrants while maintaining adequate pressure and flow.
Question 2
Water hammer in a distribution system is most commonly caused by:
A. Slow valve operation
B. Low system pressure
C. Sudden changes in water velocity
D. Excessive chlorine residual
,🟢 Correct Answer:
C. Sudden changes in water velocity
🔴 RATIONALE:
Water hammer occurs when a valve closes quickly or a pump shuts off suddenly, causing a rapid velocity
change that creates pressure surges.
Question 3
What is the minimum free chlorine residual typically required in the farthest part of a water distribution system?
A. 0.2 mg/L
B. 2.0 mg/L
C. 4.0 mg/L
D. 10.0 mg/L
🟢 Correct Answer:
A. 0.2 mg/L
🔴 RATIONALE:
Many regulatory agencies require a detectable chlorine residual of at least 0.2 mg/L in the distribution system
to ensure continued disinfection.
,Question 4
Which device is commonly used to prevent backflow from a customer's service into the public water supply?
A. Pressure-reducing valve
B. Air release valve
C. Check valve only
D. Reduced pressure zone backflow preventer
🟢 Correct Answer:
D. Reduced pressure zone backflow preventer
🔴 RATIONALE:
A reduced pressure zone backflow preventer provides protection against backpressure and backsiphonage,
preventing contamination of the potable water supply.
Question 5
The main purpose of a water storage tank is to:
A. Increase water hardness
B. Provide reserve supply and stabilize system pressure
C. Remove chlorine from water
D. Filter out sand and sediment
🟢 Correct Answer:
B. Provide reserve supply and stabilize system pressure
, 🔴 RATIONALE:
Storage tanks provide water for peak demand, fire protection, and emergency supply while helping maintain
consistent system pressure.
Question 6
What is the standard pressure unit commonly used in water distribution systems in the United States?
A. Pounds per square inch
B. Gallons per minute
C. Cubic feet per second
D. Feet per second
🟢 Correct Answer:
A. Pounds per square inch
🔴 RATIONALE:
System pressure is typically measured in pounds per square inch. Gallons per minute is flow rate, cubic feet per
second is flow, and feet per second is velocity.
Question 7
Which valve type is best suited for throttling or adjusting flow?
A. Gate valve
B. Butterfly valve
VERIFIED SOLUTIONS | UPDATED PER LATEST GUIDELINES | GRADED A+...
Question 1
What is the primary purpose of a water distribution system?
A. To treat wastewater for reuse
B. To deliver potable water to consumers at adequate pressure and quantity
C. To generate electricity
D. To store rainwater only
🟢 Correct Answer:
B. To deliver potable water to consumers at adequate pressure and quantity
🔴 RATIONALE:
A water distribution system transports treated water from the source or treatment plant to homes, businesses,
and hydrants while maintaining adequate pressure and flow.
Question 2
Water hammer in a distribution system is most commonly caused by:
A. Slow valve operation
B. Low system pressure
C. Sudden changes in water velocity
D. Excessive chlorine residual
,🟢 Correct Answer:
C. Sudden changes in water velocity
🔴 RATIONALE:
Water hammer occurs when a valve closes quickly or a pump shuts off suddenly, causing a rapid velocity
change that creates pressure surges.
Question 3
What is the minimum free chlorine residual typically required in the farthest part of a water distribution system?
A. 0.2 mg/L
B. 2.0 mg/L
C. 4.0 mg/L
D. 10.0 mg/L
🟢 Correct Answer:
A. 0.2 mg/L
🔴 RATIONALE:
Many regulatory agencies require a detectable chlorine residual of at least 0.2 mg/L in the distribution system
to ensure continued disinfection.
,Question 4
Which device is commonly used to prevent backflow from a customer's service into the public water supply?
A. Pressure-reducing valve
B. Air release valve
C. Check valve only
D. Reduced pressure zone backflow preventer
🟢 Correct Answer:
D. Reduced pressure zone backflow preventer
🔴 RATIONALE:
A reduced pressure zone backflow preventer provides protection against backpressure and backsiphonage,
preventing contamination of the potable water supply.
Question 5
The main purpose of a water storage tank is to:
A. Increase water hardness
B. Provide reserve supply and stabilize system pressure
C. Remove chlorine from water
D. Filter out sand and sediment
🟢 Correct Answer:
B. Provide reserve supply and stabilize system pressure
, 🔴 RATIONALE:
Storage tanks provide water for peak demand, fire protection, and emergency supply while helping maintain
consistent system pressure.
Question 6
What is the standard pressure unit commonly used in water distribution systems in the United States?
A. Pounds per square inch
B. Gallons per minute
C. Cubic feet per second
D. Feet per second
🟢 Correct Answer:
A. Pounds per square inch
🔴 RATIONALE:
System pressure is typically measured in pounds per square inch. Gallons per minute is flow rate, cubic feet per
second is flow, and feet per second is velocity.
Question 7
Which valve type is best suited for throttling or adjusting flow?
A. Gate valve
B. Butterfly valve
