The MARPOL
Convention
The International
Convention for the Prevention of Pollution from Ships was adopted
in 1973 and entered into force ten years later. It contains
regulations designed to prevent pollution of the sea, land and
air caused accidentally or during routine operations by ships
transporting oil cargoes, by noxious or harmful cargoes, and
by sewage and garbage. It also aims at cleaning up the oceans
and saving millions of precious oil. There are requirements
in it for storing, treating and discharging of the above mentioned
substances as well as procedures for reporting of incidents
involving dangerous goods, harmful substances and/or marine
pollutants. The convention includes the following six annexes:
I. Prevention of Pollution by Oil
II. Prevention of Pollution by Noxious Liquid Substances in
Bulk (e.g. chemicals)
III. Prevention of Pollution by Harmful Substances Carried in
Packages (e.g. containers, tanks)
IV. Prevention of Pollution by Sewage
V. Prevention of Pollution by Garbage
VI. Prevention of Air Pollution from Ships
The original MARPOL Convention 73 together with the 78 Protocol
are collectively known as MARPOL 73/78. However, it is constantly
subject to amendments designed to introduce new developments
and improve the way it is implemented.
Annex I: Prevention of pollution by oil
Annex I deals with the requirements for tankers to be capable
of operating the method of retaining oily wastes on board through
the "load on top" system or for discharge to shore
reception facilities. This involves the fitting of appropriate
equipment, including an oil-discharge monitoring and control
system, oily-water separating equipment and a filtering system,
slop tanks, sludge tanks, piping and pumping arrangements. Oil
tankers must be fitted with segregated ballast tanks (SBTs)
large enough to provide adequate operating draught without the
need to carry ballast water in cargo oil tanks. The Clean Ballast
Tank (CBT) System, and Crude Oil Washing (COW) are an alternative
to SBTs on existing tankers. Second, new oil tankers are required
to meet certain subdivision and damage stability requirements
so that, in any loading conditions, they can survive after damage
by collision or stranding. Third, both tankers and non-tankers
are obliged to carry and maintain an Oil Record Book of Machinery
Space Operations. An important point is the introduction of
"special areas" (such as the Mediterranean Sea, the
Black Sea, the Baltic Sea, the Red Sea and the Gulfs area),
which are considered to be so vulnerable to pollution by oil
that discharges of oil or oily mixtures within them have been
prohibited. Amendments made in 1992 brought in the double-hull
requirements for tankers. As an alternative, tankers may incorporate
the "mid-deck" design which means they will have double
sides but not a double bottom. Instead, another deck is installed
inside the cargo tank with the venting arranged in such a way
that there is an upward pressure on the bottom of the hull.
Strict provisions for inspection and certification procedures
are made to ensure that all ships comply with pollution prevention
measures. All but the smallest vessels must undergo an initial
survey before being issued with an International Oil Pollution
Prevention (IOPP) Certificate. Periodical surveys at intervals
not exceeding five years must be carried out, and also, at least
one intermediate survey half-way through the period of validity.
Existing tankers are to be subject to an enhanced programme
of inspections during their periodical, intermediate and annual
surveys.
Annex II: Control of pollution by noxious liquid substances
Annex II gives in detail the discharge criteria and measures
for the control of pollution by noxious liquid substances carried
in bulk. Some 250 substances were evaluated and included in
the lists of chemicals in appendices to the Convention. The
discharge of their residues is allowed only to reception facilities
until certain concentrations and conditions (which vary with
the category of substances) are complied with. In any case,
no discharge of residues containing noxious substances is permitted
within 12 miles of the nearest land. More stringent restrictions
apply to the Baltic and Black Sea areas. Further amendments
affect the International Code for the Construction and Equipment
of Ships Carrying Dangerous Chemicals in Bulk (IBC Code) making
it mandatory. This is important because the Annex itself deals
only with discharge procedures while the Code contains carriage
requirements. A second group concerns the Code for the Construction
and Equipment of Ships Carrying Dangerous Chemicals in Bulk
(BCH), which is also made mandatory under MARPOL 73/78.
Annex III: Prevention of pollution by harmful substances carried
in packaged form, or in freight containers or portable tanks
or road and rail tank wagons
Annex III contains general requirements for the issuing of detailed
standards on packing, marking, labelling, documentation, stowage,
quantity limitations, exceptions and notifications for preventing
pollution by harmful substances. The International Maritime
Dangerous Goods (IMDG) Code has, since 1991, included marine
pollutants.
Annex IV: Prevention of pollution by sewage
Annex IV deals with sewage storage, treatment and discharge
as well as the equipment approved to comply with the set regulations.
An International Sewage Pollution Prevention Certificate is
issued to this effect and states that the vessel is fitted with
a sewage treatment plant/ a comminuter/ a holding tank and a
discharge pipeline to meet the operational requirements.
Annex V: Garbage
As far as Annex V is concerned, it sets out limitations for
garbage disposal into the sea at specific minimum distances
and in “special areas”. It also takes into account
garbage handling and storage procedures, garbage processing
using incinerators, comminuters, grinding machines, etc., port
reception facilities and various other measures to ensure compliance
with the convention.
Annex VI: Air Pollution from Ships
This new Annex was added in 1997 to set limits on sulphur oxide
and nitrogen oxide emissions from ship exhausts and prohibit
deliberate emissions of ozone depleting substances. For this
purpose ships must fit an exhaust gas cleaning system or use
any other technological method to limit SOx emissions. As for
emissions of nitrogen oxides (NOx) from diesel engines a mandatory
NOx Technical Code is to be developed by IMO defining how this
is to be done. The Annex also prohibits the incineration on
board ship of certain products, such as contaminated packaging
materials and polychlorinated biphenyls (PCBs). It includes
the form of the International Air Pollution Prevention Certificate,
information for inclusion in the bunker delivery note, approval
and operating limits for shipboard incinerators, details of
surveys and inspections to be carried out, etc.
