Which of the following is NOT a common cause of lateral line failure?

Lateral line systems, which are a key component of many wastewater management systems, can experience failure due to various factors. Among these, overpopulation is not typically classified as a direct cause of lateral line failure. While high population densities can lead to increased overall demand on a wastewater system, resulting in higher flows and potential strain, this does not singularly explain failure of lateral lines.

The other options reflect specific, tangible issues that can result in lateral line failures. Physical damage to the system can come from construction, plant roots, or other environmental factors, all of which compromise the integrity of the lateral lines. Excessive water use can overwhelm these systems, leading to flooding and backflow situations that can damage the infrastructure. Furthermore, old age is a significant concern; as materials deteriorate over time, they become more susceptible to mechanical failure and blockages.

Recognizing the distinctions among these causes helps clarify the specific factors that threaten the proper function of lateral lines, reinforcing that while population pressures can impact a system's overall capacity, they do not directly cause lateral line failure.