What is a common indicator of a sewer line failure?

The presence of foul odors near manholes or the ground surface is a common indicator of a sewer line failure because it often suggests that sewage is leaking from the pipes into the surrounding soil or atmosphere. When a sewer line is damaged or blocked, wastewater can escape from the system, leading to the release of unpleasant odors caused by decomposing organic material. These odors can be particularly strong near access points like manholes, where leaks might occur. This situation not only indicates a potential failure in the sewer system but also presents health risks due to possible exposure to untreated wastewater.

The other indicators, while they can suggest various issues, do not directly point to a sewer line failure in the same clear manner. For instance, standing water can result from several factors, including stormwater drainage issues. Increased insect activity could be a sign of other types of environmental or sanitation problems but isn't specific to sewer line failures. Lower water usage by households can show a decrease in sewage flow but could arise from mere changes in household behavior rather than indicating a problem with the sewer lines.