The person in charge of a tank barge exempted under Sec. 157.08(g) from the requirements in Secs. 157.11, 157.13, 157.15, and 157.23 shall ensure that while the barge is proceeding en route:
(a) Cargo tanks are not ballasted or washed; and
(b) Oil or oily mixtures are not discharged. [CGD 74-32, 40 FR 48283, Oct. 14, 1975, as amended by CGD 76-088b, 48 FR 45721, Oct. 6, 1983; CGD 90-051, 57 FR 36244, Aug. 12, 1992]