Water Distribution Manager (WDM) Greenbook 2 Practice Exam

Regularly exercising valves keeps them operable and ready to isolate parts of the water system when needed. It prevents seizing from corrosion, deposits, or infrequent use, and it also verifies that the valve’s actuation devices, wiring, and position indication are working so operators can trust the control system during emergencies or maintenance. Critical valves—those whose operation affects large service areas or essential facilities—should be exercised on a yearly basis to maintain a reliable isolation capability. Non-critical valves can be scheduled less frequently, typically every two to three years, in line with policy, to balance reliability with available resources. This approach is proactive, not reactive, and it’s about ensuring readiness rather than surveying customers, replacing valves annually, or exercising only after a failure.