1 INTRODUCTION
These best practices are intended to assist both ship operators and port States in
assuring the proper management and disposal of EGCS residues from exhaust gas cleaning
systems (EGCSs) into port reception facilities.
2 DEFINITIONS
Discharge water: Any water from an EGCS to be discharged overboard.
Washwater: Cleaning medium brought into contact with the exhaust gas stream for
the reduction of SOX and particulate matter.
Bleed-off water: Aqueous solution removed from the washwater of an EGCS operating
in closed-loop mode to keep its required operating properties and efficiency.
EGCS residue: Material removed from the washwater or the bleed-off water by a
treatment system or discharge water that does not meet the discharge criterion, or other
residue material removed from the EGCS.
Emissions: according to regulation 2.1.12 of MARPOL Annex VIfootnote, means any release of substances, subject to control by
this Annex, from ships into the atmosphere or sea.
3 BEST PRACTICE
Discharge water from open and closed-loop EGCSs
3.1 In sea areas including ports, harbours and estuaries where the discharge of EGCS
discharge water is prohibited, ships using an EGCS should keep their discharge water on
board in dedicated holding tank(s) for delivery to port reception facilities, either in
the port of call or in the next port of call able to accept the discharge water
accordingly. However, outside these areas, the temporary stored discharge water could be
discharged into the sea in accordance with the discharge criteria given in paragraph
10.1.7 of the 2021 Guidelines for Exhaust Gas Cleaning Systems (resolution
MEPC.340(77)).
3.2 Port States should provide adequate reception facilities for this discharge.
However, depending on the number of ships that will need this service and the frequency
and amount of discharge water to be delivered, the port, in conjunction with the port
State, may decide if the appropriate reception facilities at their berths should be
permanent or provided on an individual basis.
3.3 In cases where discharge water is to be disposed of in non-permanent facilities,
ports should have arrangements with a hazardous waste contractor(s), who can supply a
suitable portable/mobile facility depending on the amount of discharge water to be
collected. For EGCS discharge water collected in either permanent or mobile facilities,
the water should be disposed of according to the appropriate and environmentally sound
waste disposal methods.
EGCS Residues
3.4 Residues generated by the EGCS should be appropriately managed on board and
delivered ashore to adequate reception facilities according to the 2011 Guidelines
for Reception Facilities under MARPOL Annex VI
(resolution MEPC.199(62)). Such residues should not be discharged into the sea.
Additionally, they should not be mixed with other waste streams and not be burnt in the
ship's incinerators.
3.5 As EGCS residues are not to be discharged into the sea, the ships that produce these
types of waste should have on board:
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.1 where applicable, evidence of a contract to prove that arrangements are in
place to deliver the waste in the region where the ship is operating;
-
.2 waste receipts from the use of that contract to prove previous deliveries of
such waste; such receipts should be kept on board for a period of 12 months after
the delivery has been made; and
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.3 an estimation of the amount of EGCS residues the produced on a daily basis,
with records of the volume of solids and sludge produced.
3.6 This information will allow the master of the ship to prove that there are
appropriate mechanisms in place to dispose of this waste in an environmentally sound
manner.