In water supply systems, small leaks are often filled over time with which substance?

In water supply systems, small leaks can attract particles and materials from the surrounding environment, which can eventually fill these gaps over time. Rust, or iron oxide, can accumulate around the leak as water interacts with iron or steel pipes. When oxygen and moisture are present, corrosion occurs, leading to the formation of rust. As rust particles dislodge or flake off, they can migrate into the leaking area, thus filling the small gaps created by the leak.

Additionally, the rust can create a barrier, temporarily reducing the flow of water from the leak. This natural sealing process can occur due to the continuous presence of water, which promotes the buildup of rust, as opposed to other substances that would not be as likely to accumulate in the same way. In the context of maintaining the integrity of water supply systems, understanding the role of rust is crucial in assessing the longevity and health of piping materials.