As informed previously by ClassNK Technical Information No. TEC-0494 issued on 15 December 2002, Annex IV of MARPOL 73/78 (Regulations for the prevention of pollution by sewage from ships) would become effective on 27 September 2003.

This technical information provides the outline of Annex IV of MARPOL 73/78 and the details for the implementation at the present.

1. The Outline of Annex IV of MARPOL 73/78
Annex IV of MARPOL 73/78 was adopted on 17 February 1978 and had not met the conditions of entry into force for many years. To assist the entry into force of Annex IV of MARPOL 73/78, while maintaining the same level of protection of the marine environment, the text of the revised Annex IV of MARPOL 73/78 was approved by the 44th session of Marine Environment Protection Committee (MEPC44, March 1990), and the MEPC Resolution (Res. MEPC.88(44)) to request the implementation of the revised Annex IV of MARPOL 73/78 immediately after entry into force of the existing Annex IV of MARPOL 73/78 was adopted at that session. At MEPC49 (July 2003), the Circular to request the port States not to apply, for the purpose of port State control, the requirements of the original Annex IV was approved and circulated.
ClassNK will apply the revised Annex IV in accordance with the above resolution immediately after entry into force of the existing Annex IV unless otherwise instructed by Flag Administrations.
The revised Annex IV is expected to be adopted by MEPC51 (March 2004) and would become effective 16 moths after the adoption (July 2005).

The following outline is based on the provisions of the revised Annex IV:

(1) Terminology (Reg.1)
(I) "New ship" means a ship:
(a) for which the building contract is placed, or in the absence of a building contract, the keel of which is laid, or which is at a similar stage of construction, on or after 27 September 2003; or
(b) the delivery of which is on or after 27 September 2006.


(To be continued)
(ii) "Existing ship" means a ship which is not a new ship.
(iii) "Sewage" means:
(a) drainage and other wastes from any form of toilets and urinals;
(b) drainage from medical premises (dispensary, sick bay, etc.) via wash basins, wash tubs and scuppers located in such premises;
(c) drainage from spaces containing living animals; or
(d) other waste waters when mixed with the drainages defined above.
(iv) "Holding tank" means a tank used for the collection and storage of sewage.

(2) Application (Reg.2)
The provisions of Annex IV of MARPOL shall apply to the following ships engaged in international voyages:
(I) new ships of 400 tons gross tonnage and above; and
(ii) new ships of less than 400 tons gross tonnage which are certified to carry more than 15 persons; and
(iii) existing ships of 400 tons gross tonnage and above, 5 years after the date of entry into force of this Annex; and
(iv) existing ships of less than 400 tons gross tonnage which are certified to carry more than 15 persons, 5 years after the date of entry into force of this Annex.

(3) Equipment for the prevention of pollution by sewage (Reg.9, 10)
The following equipment is required by the provisions of Annex IV of MARPOL 73/78:
(I) One of the following sewage systems:
(a) a sewage treatment plant which type approved by the Administration in compliance with Res.MEPC.2(VI), or
(For existing ships, national specifications are acceptable.)
(b) a sewage comminuting and disinfecting system approved by the Administra