IBTS

An Integrated Bilge Treatment System (IBTS) is a machinery-space arrangement that keeps clean and oily bilge streams separate, reducing the volume of oily bilge water that must pass through the oily water separator. It is addressed in the IMO guidance for the integrated bilge water treatment system in MEPC.1/Circ.642 (and its revision MEPC.1/Circ.642/Rev.1), which clarifies how the design interacts with MARPOL Annex I. The Annex I 15 ppm discharge standard under Regulation 14 and the oil record book under Regulation 17 still apply. The IBTS is design guidance, not a separate Annex I regulation.