In a commercial district, shut-off valves in a water main should be spaced at least every how many feet?

In a commercial district, shut-off valves in a water main are typically required to be spaced at least every 500 feet. This distance is established to ensure that there are sufficient access points for maintenance and emergency shut-offs without causing extensive disruptions to the water service. The 500-foot spacing allows for a balance between infrastructure efficiency and operational needs, enabling quick response in case of leaks or repairs. Frequent access points help water operators minimize water loss and service interruptions while maintaining effective control over the water distribution system.

Other options, while they may suggest reasonable distances, do not meet the specific requirements for commercial districts, which prioritize accessibility and control to address the needs of potentially larger and more complex water systems found in such areas.