Which set lists four types of water storage?

• A. Pipes, mains, valves, hydrants
• B. Pipes, pumps, tanks, reservoirs
• C. Ground storage, elevated tank, stand pipe, and hydro-pneumatic tank
• D. Ground storage, reservoirs, basins, cisterns

Answer: (C)

The main idea here is identifying the standard kinds of water storage used in distribution systems. The set that lists four recognized storage structures—ground storage, elevated tank, stand pipe, and hydro-pneumatic tank—covers the common ways utilities hold and pressurize water. Ground storage refers to tanks located at or below grade that store treated water; elevated tanks use height to create gravity-driven pressure; a stand pipe is a tall vertical pipe used to add storage and head; and a hydro-pneumatic tank stores water while maintaining pressure in the system. Together, these four represent the typical storage configurations you’d expect to encounter in practice and exams. The other options mix components or storage forms that aren’t grouped in this standard four, so they don’t align with the conventional set of storage types.