231. Every pit for a submersible pump or the piping of a submersible pump installed in a motor fuel dispensing outlet after 30 April 1999 must be enclosed in a liquid-tight casing resistant to petroleum products.
The casing must be covered, located and serviced in such manner as to prevent external loads being transmitted to the pump, tank or piping.
The pit must be large enough to enable the pump to be inspected and serviced.