deployment of the PLA Navy ships in the - Information Resource ...

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handler”. The details of garbage discharged into the
sea, to shore reception facility and incinerated could
be recorded in the ‘Garbage Record Book’ (sample
page is appended at the end of this paper).
Sewage Disposal and MARPOL 73/78
Annexure IV of the protocol entered into force
on 27 Sep 2003 and stipulates regulations for
discharge of sewage by ships. A gist of these
regulations is appended.
• It is prohibited to discharge sewage into
sea except when it is disinfected and discharged
at a distance of more than 4 Nm from nearest
land.
• Sewage which is not disinfected could be
discharged in to sea at a moderate rate at a
distance of more than 12 Nm from the nearest
land when the ship is enroute and proceeding
at not less than 4 knots.
Sewage Disposal in Water Bodies and
Harbours
The current practice of discharging raw
untreated sewage into water bodies and harbours
has ominous outcome for us in future. By far, the
greatest volume of waste discharged into harbours
and seas is raw and untreated sewage, which is
primarily organic in nature and subject to bacterial
decay and dilution to harmless concentrations over
a period of time. Aerobic bacterial degradation of
sewage (bacteria that uses oxygen to act upon organic
matter) results in oxidation of faecal matter to stable
inorganic compounds like H 2
O and CO 2
at the cost of
dissolved oxygen in water. However, the sheer
volume and concentration of sewage discharged in
to harbours overwhelms the natural regenerative
capacity of the water and renders it septic (severely
deprived of O 2
). The enmasse death of fish and
absence of life in harbours is a testimony of our
misdoings and a direct consequence of extremely low
levels of dissolved O 2
in water. There is yet another
process, the anaerobic oxidation in which anaerobic
bacteria decomposes the organic (faecal) matter
without using oxygen resulting in release of Hydrogen
sulphide H2S and Methane CH 4
. These gases in higher
concentration have potential to wreak havoc as H 2
s
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NAVAL DESPATCH
with an offensive rotten egg smell severely impairs
central nervous system of its victim and causes instant
death whereas CH 4
is one of the most powerful Green
House Gas with an ‘atmospheric persistence time of
12 years and having 21 times the potential of CO 2
to
warm the globe’.
Public Health Hazards
Human sewage contains enteric bacteria,
pathogens and viruses of varied and complex nature
and has enormous potential to contaminate food and
water sources. The chief health hazard is associated
with inadvertent ingestion by personnel carrying out
diving and sea bathing. Food contamination also
takes place by way of consuming sea food infected
with such pathogens while water contamination takes
place due to percolation of infected water into
ground water. As of now, there is no known natural
phenomena that can churn these super saturated
waters (with faecal matter) and result in a thorough
purging. Its a matter of time when their concentration
rises to an unmanageable level and cause wide
spread deleterious consequences, both to humanity
and other living beings.
Possible Solutions
As brought out, we need to urgently resuscitate
our water bodies and harbours . While discharging
raw sewage is a definitive No – No, partial treatment
by passing it through STPs is not a viable option either,
as the sheer volume of sewage impairs the self repair
capability of water. The other possible solutions could
be :-
• Sewage from ships could be collected into
large holding tanks ashore through a grid of
under ground pipe system where it is disinfected
and diluted before discharging deep into sea.
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