Why are frozen water mains a significant concern for water supply?

Frozen water mains are a significant concern for water supply because they can lead to complete service interruptions. When a water main freezes, the water within it expands, creating pressure that can cause the pipe to crack or burst. This not only stops the flow of water, leading to disruptions for consumers, but can also complicate the repair process and require significant resources to restore service. It's particularly concerning in colder climates or during severe winter conditions, as it means that many customers may be left without access to water for drinking, sanitation, and other essential uses.

The other options do not accurately represent the implications of frozen water mains. Excessive pressure buildup may occur in certain situations, but it is the resulting service interruption that poses the most serious concern. Alternatively, faster water delivery and help in filtration processes are unrelated to issues stemming from frozen pipes.