3.8 HULL CLEANING OF DRY-DOCKED VESSELS

It is a legal requirement that ships be dry-docked for cleaning, repair and maintenance of hulls at least once every five years⁵⁵ When a vessel is dry-docked, the hull is usually cleaned by high pressure water jets and grit blasters⁵⁶ In Victoria, there is one dry-dock facility at Williamstown, and two commercial slipways; one at Victoria Dock in Melbourne and one at Rippleside in Geelong. Operators are required by the EPA to dispose of hull cleaning waste to appropriate on-shore sites⁵⁷ It has been suggested, however, that at some shipyards, biological materials and fine particles from on-shore cleaning of hulls are washed back into the water⁵⁸ The Committee notes that disposal of biological and chemical waste in such a manner negates any benefit derived from the prohibition of in-water hull cleaning.