Sewage Water testing according to the Annex IV of MARPOL

MARPOL Annex IV controls:

  • Discharge of sewage into the sea 
  • Ships equipment and systems
  • Provision of facilities at ports and terminals
  • Requirements for survey and certification 

The Annex entered into force on 27 September 2003. A revised Annex IV was adopted on 1 April 2004 and entered into force on 1 August 2005.
The revised Annex applies to new ships engaged in international voyages of 400 gross tonnage and above or which are certified to carry more than 15 persons. Existing ships are required to comply with the provisions of the revised Annex IV five years after the date of entry into force of Annex IV, namely since 27 September 2008. The Annex requires ships to be equipped with either an approved sewage treatment plant or an approved sewage comminuting and disinfecting system or a sewage holding tank.

The discharge of sewage into the sea is prohibited, except when the ship has in operation an approved sewage treatment plant or when the ship is discharging comminuted and disinfected sewage using an approved system at a distance of more than three nautical miles from the nearest land. Sewage which is not comminuted or disinfected has to be discharged at a distance of more than 12 nautical miles from the nearest land.

Resolution MEPC.159(55), which entered into force on 1st January 2010, consists of the revised guidelines for implementation of effluent standards and performance tests for sewage treatment plants.

Vessels which fall under the above mentioned categories will need to demonstrate compliance with the regulations, with the relevant certification (ISPPC).

ISPCC (International Sewage Pollution Prevention Certificate) are issued upon successful inspection and are valid for 5 years.

Non-compliance or failed inspections can result in vessel detention

According to MEPC.159(55) below mentioned parameters have to be controlled to prove the vessels sewage treatment plants functionality.