What could a drastic increase in water delivery time for a dry standpipe indicate?

A drastic increase in water delivery time for a dry standpipe could most accurately suggest corrosion in the system piping. Corrosion can cause gradual degradation of pipe walls, leading to narrowing of the internal diameter and, ultimately, increased resistance to water flow. This results in slower delivery times as water has to overcome the restricted pathways created by the corrosion buildup.

While other factors such as blockages, insufficient water supply, or pump failure could also contribute to increased delivery times, the nature of corrosion specifically leads to a predictable and measurable increase over time, making it a key indicator. Analyzing the system for signs of corrosion—such as rust or pitting on the pipe surface—can help identify this cause effectively. Therefore, recognizing corrosion as a potential problem is crucial for maintaining the efficiency and safety of the standpipe system.