Which statement best describes backup water sources in NFPA 13E?

• A. Backup water sources must be maintained only in facilities with more than 1,000 occupants.
• B. Backup water sources are optional in most facilities.
• C. The standard requires backup water sources if the primary supply is compromised.
• D. Backup water sources are not addressed by NFPA 13E.

Answer: (C)

Backup water sources are included to keep sprinkler systems supplied even when the main water source is unavailable. NFPA 13E, which focuses on protecting existing occupancies, expects a secondary water source to be in place whenever there's a real risk that the primary supply could be compromised—such as due to a water-main break, service interruption, or high demand during a fire. Having an alternative source—like a secondary water line, on-site storage, or a connection to another water supply—ensures the system can still deliver the required flow and pressure to control the fire. This approach isn’t optional, and NFPA 13E addresses the need for backup sources to maintain reliable fire protection.