The Integrated Bilge Water Treatment System (IBTS) concept was promoted by Japan and recognised by the IMO through its MEPC.1/Circ 642 as an excellent concept to minimise the amount of oily bilge water generated in machinery spaces and with an integrated means to process the oily bilge water and oil residue (sludge).
In principle, the IBTS is a concept of an installation containing a bilge primary tank and proper control of the flow of drain streams, aiming to segregate as much as possible oily streams from the drain streams of clean water, and avoid their admixture.
Unfortunately, ships which use oily water separator systems based on the IBTS concept have reported negative experiences with port state control officers who are not convinced that ships can generate significantly low oily water volumes.
To avoid this, Japan and the International Association of Classification Societies (IACS) have suggested that ships equipped with installations based on the IBTS concept are given a Statement of Fact, which is a check list acknowledging that the installation follows the IBTS as described in MEPC .1/Circ. 642.
INTERTANKO and other ship owner organisations supported the promotion of IBTS. INTERTANKO recommended that Governments invite ship designers and ship builders to include IBTS as standard systems in all new buildings.
Source : INTERTANKO