30 CFR § 57.4430
Surface storage facilities.
The requirements of this standard apply to surface areas only.
(a) Storage tanks for flammable or combustible liquids shall be--
(1) Capable of withstanding working pressures and stresses
and compatible with the type of liquid stored;
(2) Maintained in a manner that prevents leakage;
(3) Isolated or separated from ignition sources to prevent
fire or explosion; and
(4) Vented or otherwise constructed to prevent development
of pressure or vacuum as a result of filling, emptying, or atmospheric
temperature changes. Vents for storage of Class I, II, or IIIA liquids shall
be isolated or separated from ignition sources. These pressure relief
requirements do not apply to tanks used for storage of Class IIIB liquids
that are larger than 12,000 gallons in capacity.
(b) All piping, valves, and fittings shall be--
(1) Capable of withstanding working pressures and
(2) Compatible with the type of liquid stored; and
(3) Maintained in a manner that prevents leakage.
(c) Fixed, unburied tanks located where escaping liquid could present
a hazard to persons shall be provided with--
(1) Containment for the entire capacity of the largest
(2) Drainage to a remote impoundment area that does not
endanger persons. However, storage of only Class IIIB liquids does not
require containment or drainage to remote impoundment.