What is the minimum residual pressure required in a distribution system without public notification?

The minimum residual pressure of 20 psi in a water distribution system is crucial for ensuring that the system can continue to deliver adequate water supply during peak usage times and emergencies, without needing to notify the public. This pressure threshold helps to maintain adequate water flow and system integrity, which is essential for both domestic and fire protection purposes.

Maintaining a minimum of 20 psi is especially important as it allows for the proper functioning of plumbing fixtures and appliances in residences, ensuring that water can be delivered effectively to various points within the system. Furthermore, it helps to prevent backflow and contamination, as higher pressures offer better resistance to infiltration of pollutants from the surrounding environment.

Additionally, this standard is often set by regulatory agencies to promote public health and safety, and it serves as a guideline for water operators to manage their distribution systems effectively. Inadequate pressure can lead to service disruptions, dissatisfaction among users, and potential public health risks, which is why this pressure level is essential for operational compliance and community assurance.