How should the integrity of a water distribution system be verified during recovery?

• A. Residual disinfection testing, pressure testing, and coordination with water utility/public health authorities
• B. Visual inspection alone
• C. Testing only at a single hydrant
• D. Waiting 48 hours then reopening

Answer: (A)

The main idea here is to confirm that the water system is truly ready to be stored and used again by checking chemical safety, hydraulic performance, and regulatory oversight. Residual disinfection testing makes sure there is an adequate and stable level of disinfectant throughout the distribution network, so microbes are kept in check as the system ramps back up. Pressure testing verifies that the system can maintain appropriate pressure and helps detect leaks or compromised sections that could allow contaminants to enter or backflow to occur. Coordinating with the water utility and public health authorities ensures the restart follows proper procedures, includes appropriate sampling plans, and aligns with regulatory and advisory requirements so the public is protected.

Relying on visual inspection alone won’t reveal whether disinfectant levels are sufficient or whether the system is maintaining pressure, and testing only at a single hydrant isn’t representative of the entire network. Waiting 48 hours before reopening delays needed verification and can leave uncertainties about safety and system integrity.