“Containment sump” means a liquid-tight container, with or without secondary containment, that protects the environment by containing leaks and spills of regulated substances from piping, dispensers, pumps, and related components in the containment area. The term includes containment sumps located:

1. (a) At the top of the tank, known as tank top or submersible turbine pump sumps;
2. (b) Underneath the dispenser, known as under-dispenser containment sumps, dispenser sumps, and under-dispenser sumps; and
3. (c) At other points in the piping run, known as piping sumps, transition sumps, intermediate sumps, low-point sumps, and piping vaults.

Source. #12643, eff 10-10-18 (See Revision Note #2 at chapter heading for Env-Or 400)