(a) The direct discharge of elevator pit effluent is prohibited.

(b) Notwithstanding the prohibition of direct discharges of elevator pit effluent overboard, if the elevator pit effluent is commingled with any other discharge for the purposes of treatment prior to discharge, then under no circumstances may oils, including oily mixtures, be discharged from that combined discharge in quantities that:

(1) Cause a film or sheen upon or discoloration of the surface of the water or adjoining shorelines; or

(2) Cause a sludge or emulsion to be deposited beneath the surface of the water or upon adjoining shorelines; or

(3) Contain an oil content above 15 ppm as measured by EPA Method 1664a or other appropriate method for determination of oil content as accepted by the International Maritime Organization (IMO) (e.g., ISO Method 9377) or U.S. Coast Guard; or

(4) Otherwise are harmful to the public health or welfare of the United States.