Which of the following can lead to water main breaks in distribution systems?

Thermal expansion and corrosion are significant factors that can lead to water main breaks in distribution systems. When water heats up, it expands, which can create additional pressure within the pipes. If this pressure exceeds the structural integrity of the pipe, it can lead to ruptures or breaks. Corrosion, on the other hand, weakens the pipe material over time, especially in environments where the water chemistry is aggressive toward the materials used in the pipes. As the integrity of the pipe diminishes due to corrosion, it becomes more susceptible to failure under normal operating pressures or during temperature fluctuations.

In contrast, high water usage during peak hours primarily leads to increased flow and pressure demands but is less directly related to the physical state of the pipes when compared to thermal expansion and corrosion. Short pipe lengths and minimal fittings may reduce the chances of leaks, while increased filtration processes typically focus on water quality rather than structural integrity, thus not being a direct contributor to main breaks.