Dirty ballast is water which may contain residual fuel and other constituents as a result of sea water being stored in fuel tanks. Dirty ballast is discharged to the environment after being processed through OCMs (Oil Content Monitors) and/or OWS (oily water separator) systems that ensure the ballast water fuel/oil concentrations are below Federal standards. The discharge is infrequent and occurs just above the waterline of the ship. The possible sources of the constituents of dirty ballast are seawater, fuel remaining in the tank, fuel additives, materials used in the ballast system, and the zinc anodes in the fuel tanks.

The Gulf Area - is the special area and protected by IMO regulation and rules. By these rules all ships in Gulf Area`s ports should discharge dirty ballast water through waste management organizations. Ballast water contains a variety of organisms including bacteria and viruses and the adult and larval stages of the many marine and coastal plants and animals. While the vast majority of such organisms will not survive to the point when the ballast is discharged, some may survive and thrive in their new environment. These ‘non-native species’, if they become established, can have a serious ecological, economic and public health impact on the receiving environment. (Learn more)

Tankers may be prohibited from discharging ballast water in the port area. Similar procedures have been noted in other Gulf area ports and members are advised to note previous problems relating to alleged off-spec ballast water particularly as the port authority has noted that 'violation of the above requirements may cause considerable delays and huge losses'. Tankers will be prohibited from discharging ballast water until a ballast exchange has been carried out outside the ecological zone.