The tank dyke design is intended to contain what in the event of a leak?

• A. Only rainwater
• B. The entire contents of the tank
• C. Only the vapor
• D. Only the leaking portion

Answer: (B)

Tank dykes are built as secondary containment around a storage tank so that any liquid that escapes stays within a barrier and can be recovered. The design is meant to hold the full volume of what’s in the tank, in a leak scenario, rather than just rainwater, vapor, or only the portion that leaks first. This ensures there’s enough capacity to contain a worst‑case release and prevent environmental damage. (In practice, you also consider rainfall that may collect in the dyke, but the main purpose is to contain the entire tank contents.)