What is the minimum residual pressure that a public water supply system should maintain?

Maintaining a minimum residual pressure in a public water supply system is crucial for ensuring adequate water delivery and system integrity. A residual pressure of 35 psi is recognized as a standard appropriate level for most public water supply systems. This level helps in preventing backflow, maintaining water quality, and ensuring that there is enough pressure for firefighting and other emergency services. Additionally, it aids in minimizing the risk of contamination from outside sources. While lower pressures may sometimes be considered, they can compromise system performance and safety, which is why 35 psi is the recommended minimum standard.