40 CFR 139.25: Non-oily machinery.

(a) The requirements in paragraph (b) of this section apply to discharges from machinery that contains no oil, including but not limited to discharges from the operation of desalination systems, water chillers, valve packings, water piping, low- and high-pressure air compressors, propulsion engine jacket coolers, fire pumps, and seawater and potable water pumps.

(b) The discharge of untreated non-oily machinery wastewater and packing gland or stuffing box effluent containing toxic or bioaccumulative additives, or the discharge of oil in such quantities as may be harmful, is prohibited.