1. The primary purpose of a water distribution system is to:
A. Treat raw water
B. Store wastewater
C. Deliver potable water to consumers
D. Test water quality
ANSWER : C
Explanation:
A distribution system’s main job is to deliver safe drinking water from
treatment plants or sources to customers.
2. Which component stores water and helps maintain system pressure?
A. Fire hydrant
B. Storage tank
C. Service line
D. Water meter
ANSWER : B
Explanation:
Storage tanks provide water supply during peak demand and help maintain
consistent pressure.
3. What unit is commonly used to measure water pressure?
A. Gallons
B. PSI
C. Feet per second
D. NTU
ANSWER : B
,Explanation:
Water pressure is measured in pounds per square inch (PSI).
4. Normal residential water pressure should typically be between:
A. 10–20 PSI
B. 20–30 PSI
C. 35–80 PSI
D. 100–150 PSI
ANSWER : C
Explanation:
Most systems operate safely between 35 and 80 PSI to avoid damage or low
flow.
5. A device used to control or shut off water flow is called a:
A. Meter
B. Valve
C. Pump
D. Hydrant
ANSWER : B
Explanation:
Valves allow operators to control flow, isolate sections, and perform
maintenance.
6. Which valve is commonly used to isolate sections of a water main?
A. Relief valve
B. Gate valve
C. Check valve
D. Float valve
ANSWER : B
Explanation:
Gate valves are designed for fully open or fully closed operation.
,7. A check valve is used to:
A. Increase pressure
B. Prevent backflow
C. Measure flow
D. Drain pipelines
ANSWER : B
Explanation:
Check valves allow flow in one direction only, protecting against backflow.
8. What material is most commonly used for modern water mains?
A. Lead
B. Clay
C. Ductile iron
D. Copper
ANSWER : C
Explanation:
Ductile iron is strong, durable, and widely used in distribution systems.
9. Which pipe material is NOT acceptable for potable water?
A. PVC
B. Copper
C. Lead
D. Ductile iron
ANSWER : C
Explanation:
Lead is unsafe due to health risks and is no longer allowed.
10. Water flowing backward into the distribution system is called:
A. Headloss
B. Backflow
C. Turbidity
D. Cross-connection
, ANSWER : B
Explanation:
Backflow occurs when pressure reverses, allowing contaminants to enter the
system.
11. A cross-connection is:
A. A broken water main
B. A pipe intersection
C. A link between potable and non-potable water
D. A type of valve
ANSWER : C
Explanation:
Cross-connections are dangerous because they can contaminate drinking
water.
12. What device prevents backflow at a service connection?
A. Pressure gauge
B. Backflow preventer
C. Gate valve
D. Flow meter
ANSWER : B
Explanation:
Backflow preventers protect the water supply from contamination.
13. Fire hydrants are primarily used to:
A. Measure flow
B. Store water
C. Provide access for firefighting and flushing
D. Increase pressure
ANSWER : C
Explanation:
Hydrants allow fire protection and help with system flushing.
A. Treat raw water
B. Store wastewater
C. Deliver potable water to consumers
D. Test water quality
ANSWER : C
Explanation:
A distribution system’s main job is to deliver safe drinking water from
treatment plants or sources to customers.
2. Which component stores water and helps maintain system pressure?
A. Fire hydrant
B. Storage tank
C. Service line
D. Water meter
ANSWER : B
Explanation:
Storage tanks provide water supply during peak demand and help maintain
consistent pressure.
3. What unit is commonly used to measure water pressure?
A. Gallons
B. PSI
C. Feet per second
D. NTU
ANSWER : B
,Explanation:
Water pressure is measured in pounds per square inch (PSI).
4. Normal residential water pressure should typically be between:
A. 10–20 PSI
B. 20–30 PSI
C. 35–80 PSI
D. 100–150 PSI
ANSWER : C
Explanation:
Most systems operate safely between 35 and 80 PSI to avoid damage or low
flow.
5. A device used to control or shut off water flow is called a:
A. Meter
B. Valve
C. Pump
D. Hydrant
ANSWER : B
Explanation:
Valves allow operators to control flow, isolate sections, and perform
maintenance.
6. Which valve is commonly used to isolate sections of a water main?
A. Relief valve
B. Gate valve
C. Check valve
D. Float valve
ANSWER : B
Explanation:
Gate valves are designed for fully open or fully closed operation.
,7. A check valve is used to:
A. Increase pressure
B. Prevent backflow
C. Measure flow
D. Drain pipelines
ANSWER : B
Explanation:
Check valves allow flow in one direction only, protecting against backflow.
8. What material is most commonly used for modern water mains?
A. Lead
B. Clay
C. Ductile iron
D. Copper
ANSWER : C
Explanation:
Ductile iron is strong, durable, and widely used in distribution systems.
9. Which pipe material is NOT acceptable for potable water?
A. PVC
B. Copper
C. Lead
D. Ductile iron
ANSWER : C
Explanation:
Lead is unsafe due to health risks and is no longer allowed.
10. Water flowing backward into the distribution system is called:
A. Headloss
B. Backflow
C. Turbidity
D. Cross-connection
, ANSWER : B
Explanation:
Backflow occurs when pressure reverses, allowing contaminants to enter the
system.
11. A cross-connection is:
A. A broken water main
B. A pipe intersection
C. A link between potable and non-potable water
D. A type of valve
ANSWER : C
Explanation:
Cross-connections are dangerous because they can contaminate drinking
water.
12. What device prevents backflow at a service connection?
A. Pressure gauge
B. Backflow preventer
C. Gate valve
D. Flow meter
ANSWER : B
Explanation:
Backflow preventers protect the water supply from contamination.
13. Fire hydrants are primarily used to:
A. Measure flow
B. Store water
C. Provide access for firefighting and flushing
D. Increase pressure
ANSWER : C
Explanation:
Hydrants allow fire protection and help with system flushing.
