AWWA Operational Efficiency and Maintenance

Question 1

What is the purpose of performing a unidirectional flushing (UDF) operation in water distribution systems?

Accepted Answer

To remove sediment and stagnant water

Answer

Unidirectional flushing (UDF) is a systematic method used in water distribution systems to clean pipelines. By opening and closing valves in a specific sequence, water is directed through sections of pipe at high velocities in one direction. This process effectively scours the pipe walls, dislodging and removing accumulated sediment, biofilm, and stagnant water, thereby improving water quality and restoring hydraulic capacity.

Question 2

What is the recommended frequency for calibrating flow meters in a water distribution system?

Accepted Answer

Annually

Answer

Annual calibration is recommended for flow meters to ensure their accuracy and reliability in measuring water usage. This frequency helps maintain system efficiency, prevents inaccurate billing, and ensures compliance with regulatory standards by catching potential drifts in measurement over time.

Question 3

What is the common method for detecting leaks in a water distribution system?

Accepted Answer

Acoustic monitoring

Answer

Acoustic monitoring is a common and effective method for detecting leaks in water distribution systems. It involves using specialized equipment to listen for the sound waves and vibrations generated by water escaping from pipes, allowing technicians to pinpoint the exact location of underground leaks without extensive excavation.

Question 4

What is the recommended water velocity for efficient pipeline cleaning during maintenance?

Accepted Answer

5 ft/s

Answer

A water velocity of 5 ft/s is recommended for efficient pipeline cleaning because it provides sufficient scouring action to dislodge accumulated sediment and debris from the pipe walls. This velocity is high enough to be effective without being so excessive that it risks damaging the pipeline or creating unsafe conditions during maintenance.

Question 5

What is the primary purpose of performing valve exercising in a water distribution system?

Accepted Answer

To prevent valve seizing and ensure operability

Answer

The primary purpose of performing valve exercising is to prevent valves from seizing due to corrosion or sediment buildup, thereby ensuring they remain fully operable. Regular exercising confirms that valves can be opened or closed quickly and reliably during emergencies, maintenance, or system adjustments, maintaining critical control over water flow.

(AWWA) American Water Works Association Practice Test

(AWWA) American Water Works Association Practice Test

AWWA Operational Efficiency and Maintenance