If a tank vessel having a COW system meeting § 157.10a(a)(2) or § 157.10c(b)(2) does not have segregated ballast tanks or dedicated clean ballast tanks that meet § 157.10c(c)(2) , the owner, operator, and master shall ensure that the vessel carries only the grades of crude oil that can be used for crude oil washing.
33 C.F.R. §157.172