Class B Exam Practice Questions And

Water System Operations Specialist Class B Exam Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• Which of the following is the primary purpose of a water distribution

system?

• To treat water to drinking water standards
• To remove solids from water
• To deliver potable water to consumers safely and reliably
• To generate electricity

Rationale: The main purpose of a water distribution system is to

transport treated water from the plant to consumers while maintaining water quality and pressure. 1 / 4

• What is the typical minimum residual chlorine concentration required

in a distribution system to ensure disinfection?

• 0.1 mg/L
• 0.2 mg/L
• 0.5 mg/L
• 1.0 mg/L

Rationale: A minimum residual of 0.5 mg/L of chlorine is generally

recommended in the distribution system to prevent microbial growth.

• Which type of pipe material is most commonly used for potable water

distribution?

• Galvanized steel
• Ductile iron
• Cast iron
• Copper

Rationale: Ductile iron is widely used due to its strength, durability,

and suitability for potable water applications.

• What is the main function of a water storage tank?
• To treat water
• To provide storage for peak demand and maintain system pressure
• To remove contaminants
• To distribute water directly from source

Rationale: Water storage tanks balance supply and demand, maintain

pressure, and provide emergency storage. 2 / 4

• What is the most common method for leak detection in a water

distribution system?

• Visual inspection only
• Acoustic leak detection
• Chemical testing
• Flow cytometry

Rationale: Acoustic leak detection uses sound to identify leaks in

buried pipes, which is highly effective and widely used.

• Which of the following causes the most water loss in distribution

systems?

• Evaporation
• Leaks and pipe breaks
• Consumption measurement errors
• Backflow

Rationale: Leaks and pipe breaks are the leading causes of water loss

in distribution systems, often termed “real losses.”

• What is the function of a PRV (Pressure Reducing Valve) in a

distribution system?

• To increase flow
• To prevent leaks
• To maintain safe downstream pressure
• To treat water 3 / 4

Rationale: PRVs reduce high pressures to safe levels to prevent pipe

damage and reduce leakage.

• What is the purpose of hydrants in a water system?
• To treat water
• To provide access for firefighting and system flushing
• To store water
• To pump water to consumers

Rationale: Hydrants allow firefighters to access water and help

operators flush the system to maintain water quality.

• What is a common cause of low pressure in a water distribution

system?

• Excess chlorine
• High water temperature
• High demand or pump failure
• Pipe color

Rationale: Low pressure often occurs during periods of high demand,

pump malfunctions, or valve issues.

• Which device prevents backflow from contaminating the potable

water supply?

A. PRV

• Flowmeter
• Backflow preventer
• Hydrant
• / 4