At what height above the highest service connection must water be stored to meet the state's minimum normal operating pressure of 35 psi?

To determine the height above the highest service connection necessary to maintain a minimum operating pressure of 35 psi, you need to consider the relationship between elevation and pressure in a water distribution system.

Pressure in a water system can be measured in feet of water column, wherein 1 psi is equivalent to about 2.31 feet of water. Therefore, to convert the pressure requirement to the equivalent height, you multiply the psi value by the conversion factor.

For a minimum operating pressure of 35 psi: 35 psi × 2.31 feet/psi ≈ 80.85 feet.

This indicates that to ensure that there is a constant water pressure of at least 35 psi at the highest service connection, water must be stored at a minimum height of approximately 80.85 feet above that connection. This height allows for the water column to exert sufficient pressure to meet the operational needs of the system while accounting for friction losses and other factors that may impact pressure in the distribution system.

The correct answer aligns perfectly with this calculation and ensures compliance with state regulations regarding water pressure.