Valve vault drains in a water distribution system should be connected to which of the following?

• A. Absorption pit
• B. Sump basin
• C. Retention chamber
• D. Storm sewer

Answer: (A)

Draining valve vaults is meant to remove infiltrated or precipitation water from the underground chamber and dispose of it in a way that won’t affect the potable water system or overload other drainage utilities. Connecting valve vault drains to an absorption pit lets that water percolate into the surrounding soil in a controlled, dispersed manner, reducing the risk of backflow into the distribution system and avoiding introducing drainage into sanitary or storm sewer networks.

Using a sump basin would keep water inside the vault area and often require pumping, which adds complexity and potential failure points. A retention chamber would hold water rather than dispose of it, and routing to a storm sewer pushes water into a separate drainage system, which can create cross-connection and contamination concerns. Therefore, the proper discharge path is an absorption pit.