What should we do with sewage water?

The discharge of raw sewage into the sea can create a health hazard. Annex IV contains a set of regulations regarding the discharge of sewage into the sea from ships, including regulations regarding the ships' equipment and systems for the control of sewage discharge, the provision of facilities at ports and terminals for the reception of sewage, and requirements for survey and certification. It also includes a model International Sewage Pollution Prevention Certificate to be issued by national shipping administrations to ships under their jurisdiction.

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.

The amendment introduces the Baltic Sea as a special area under Annex IV and adds new discharge requirements for passenger ships while in a special area. The discharge of sewage from passenger ships within a special area are generally prohibited under the new regulations, except when the ship has in operation a sewage treatment plant which shall be of a type approved by the national Administration.

 

5. What is MARPOL? / Annex V?

The MARPOL Convention is the main international convention covering prevention of pollution of the marine environment by ships from operational or accidental causes. The International Convention for the Prevention of Pollution from Ships (MARPOL) was adopted on 2 November 1973 at IMO and covered pollution by oil, chemicals, harmful substances in packaged form, sewage and garbage.

Revised MARPOL Annex V sets new regulatory requirements regarding the disposal of garbage from ships and will come into force on 1 January 2013. The new amendments prohibit the disposal of almost all kinds of garbage at sea with the exemption under specific requirements of food waste, animal carcasses, cargo residues contained in wash water and environmental friendly cleaning agents. As a result of these regulations more and more ships will dispose their ship-generated waste to reception facilities ashore. MARPOL Annex V applies to all ships.

Generally, discharge is restricted to food wastes, identified cargo residues, animal carcasses, and identified cleaning agents and additives in washwater which are not harmful to the marine environment. Garbage discharge regulations do not apply when the discharge of garbage from a ship was a necessary action for the purpose of securing the safety of a ship and those on board or saving life at sea. In such cases an entry should be made in the Garbage Record Book, or in the ship’s official log-book for ships of less than 400 gross tonnage.

According to revised MARPOL Annex V shipboard generated garbage is to be grouped into the following categories:

1. Plastics - Garbage that consists of or includes plastic in any form, including synthetic ropes, synthetic fishing nets, plastic garbage bags and incinerator ashes from plastic products. Garbage under this category is prohibited to be discharged at sea.

2. Food wastes – Spoiled or unspoiled food substances. Food wastes may be discharged at sea under specific circumstances/requirements (refer to the simplified overview of the discharge provisions of the revised MARPOL Annex V developed by IMO).

3. Domestic Wastes – Garbage generated mainly in the accommodation spaces on board the ship (e.g. drinking bottles, papers, cardboard etc). Garbage under this category is prohibited to be discharged at sea.

4. Cooking Oil – Edible oil or animal fat used for the preparation or cooking of food. Garbage under this category is prohibited to be discharged at sea.

5. Incinerator ashes - Ash and clinkers resulting from shipboard incinerators used for the incineration of garbage. Garbage under this category is prohibited to be discharged at sea.

6. Operational wastes - Solid wastes (including slurries) that are collected on board during normal maintenance or operations of a ship, or used for cargo stowage and handling. Operational wastes also includes cleaning agents and additives contained in cargo hold and external wash water that may be harmful to the aquatic environment. Operational wastes does not include grey water, bilge water, or other similar discharges essential to the operation of a ship (boiler/economizer blowdown, gas turbine washwater, machinery wastewater etc). Garbage under this category is prohibited to be discharged at sea.

7. Cargo residues - Remnants of any cargo which remain on the deck or in holds following loading or unloading. This category does not include cargo dust remaining on the deck after sweeping or dust on the external surfaces of the ship. Such garbage may be discharged at sea under specific circumstances/requirements (refer to the simplified overview of the discharge provisions of the revised MARPOL Annex V developed by IMO). It is essential to remember that besides other requirements (e.g. distance from shore) cargo residues in order to be discharged at sea they should not be harmful to the marine environment. Cargo residues which are considered harmful to the marine environment are classified according to the criteria of the United Nations Globally Harmonized System for Classification and Labelling of Chemicals (UN GHS) meeting parameters such as: acute aquatic toxicity category 1, chronic aquatic toxicity category, carcinogenicity, mutagenicity, reproductive toxicity etc

8. Animal Carcasses – Bodies of any animals that are carried on board as cargo and that die or are euthanized during the voyage. Discharge of such wastes permitted at sea under specific circumstances/requirements (refer to the simplified overview of the discharge provisions of the revised MARPOL Annex V developed by IMO).

9. Fishing Gear - Physical device that may be placed on or in the water or on the sea-bed with the intended purpose of capturing marine or fresh water organisms. Garbage under this category is prohibited to be discharged at sea.