What is the minimum water supply capability for a standpipe system?

• A. 60 minutes of uninterrupted operation
• B. The system demand for at least 30 minutes
• C. 15 minutes of flow at 200 gpm
• D. Infinite supply

Answer: (B)

The minimum water supply capability for a standpipe is that the water supply must meet the standpipe’s calculated system demand for at least 30 minutes. The term “system demand” refers to the flow rate the standpipe is designed to deliver under expected conditions, determined by hydraulic calculations that account for fittings, elevation losses, and outlet use. Having this duration ensures firefighters have enough water to operate the standpipe and continue suppression efforts while additional water sources or pumps come online. Options proposing 60 minutes, 15 minutes at a fixed flow, or infinite supply don’t align with the standard baseline; the typical requirement is the system demand sustained for 30 minutes.