What is the first step an operator should take when a large main break occurs?

When a large main break occurs, the first step an operator should take is to locate the valves that isolate the leak. This is crucial because quickly identifying and shutting off the valves will help minimize the water loss and prevent further damage to the surrounding infrastructure. It also aids in controlling the pressure in the system, which can lead to more effective repairs. Isolating the leak is essential to managing the situation properly and allows the operator to assess the impact of the break on the overall water distribution system.

While notifying management, beginning repairs, or assessing water loss are all important actions to take in the aftermath of a main break, they should follow the immediate step of isolating the leak to ensure that the situation does not worsen and to protect both resources and public safety.