A satisfactory means of preventing solvent leakage from the enclosure shall be provided. This shall include some method of diking completely around the dry cleaning machine base and service area. A masonry dike or a recessed floor area is recommended. The frontal projection of the dike shall be sufficient to catch any solvent which leaks from the loading door of the machine. The dike shall have a minimum height of two inches. The floor area within the dike shall be sloped to a gravity drain which connects to a properly sized solvent holding tank.
(1974 Code § 7.238)