In a standpipe system within a building, water outlets on multiple floors are supplied by what means?

• A. Pumped to supply standpipe outlets
• B. Gravity-fed from rooftop tanks
• C. Only connected to external hydrants
• D. Not connected to the building's water supply

Answer: (A)

Standpipe water on multiple floors needs a pressure-boosting supply, so it is pumped to the standpipe outlets. A fire pump within the building (or a dedicated standpipe/fire pump) provides the necessary pressure to push water up through the vertical risers and overcome elevation and friction losses on higher floors. Gravity alone generally cannot deliver adequate pressure to upper levels, except in uncommon designs with large rooftop storage designed specifically for gravity feed. Standpipes are connected to the building’s water supply (often via the fire pump or an adequate municipal supply), not fed only from external hydrants or left disconnected.