During maintenance, if water is still flowing in the system, what safety procedure should be followed?

Monitoring pressure and maintaining communication during maintenance when water is still flowing in the system is essential for several reasons. Firstly, it ensures that the system remains within safe operating limits, as fluctuations in pressure can lead to leaks or system failures. By keeping an eye on the pressure, operators can respond promptly to any anomalies that may arise during maintenance activities.

Additionally, maintaining communication is crucial for coordinating efforts with other personnel involved in the maintenance process. It allows for real-time information sharing and timely responses to any emergencies or unexpected changes in the system status. This approach ensures that both the safety of the workers and the integrity of the water supply system are upheld.

In contrast, the other options present risks. Sending notifications to customers without monitoring the ongoing system conditions may lead to customer confusion or complaints, especially if there are sudden changes in service. Shutting off all valves immediately can disrupt water supply and create pressure surges that might cause additional problems. Allowing unrestricted flow without proper oversight could lead to uncontrolled situations, including flooding or other hazards. Therefore, monitoring pressure and maintaining effective communication are the safest and most responsible practices during ongoing maintenance.