Sewage Prevention for DCVs

In accordance with section 53 of the Marine Pollution Act 2012, vessels must not discharge sewage into State waters. Owners and operators need to ensure their vessel(s) systems are maintained in good condition and no modifications are made prior to approval from TfNSW Maritime.


All vessels in NSW with a toilet or sink on board are to have means in place for preventing pollution. Class 4 commercial vessels  with a toilet on board are to be fitted with a sewage system in accordance with the Marine Pollution Regulations 2014. Holding tanks of a suitable volume are to be provided on board or a Plan of Management for waste is to be approved for the vessel and its operation.

Owner responsibilities

In addition to the requirements to prevent pollution, the owner may have the following responsibilities to ensure environmental and safety issues are addressed:

  • ensure that any toilet, holding tank and associated fitting on the vessel is maintained in good condition
  • ensure that when all removable gas-tight covers are secured in position, the holding tank and its fittings (except for the vent pipe) are thoroughly gas-tight under normal operating conditions
  • ensure that any greywater tank on the vessel is maintained in a good and serviceable condition
  • any holding tank on the vessel should not be modified or removed unless consent is obtained from TfNSW Maritime
  • if a vessel is installed with an on-board certified sewage treatment system the owner must ensure that it is maintained in good condition and does not exceed its maximum treatment capacity as specified by the manufacturer.

Hydrogen Sulphide gas exposure

Hydrogen sulphide collects in confined spaces and poorly ventilated or enclosed areas in a vessel that contains a sewage holding tank or other parts of sewage systems. Exposure to this gas can be lethal. Hydrogen Sulphide gas can escape if organic matter or sludge is disturbed in a sewage system that is damaged, malfunctioning or connections are not tight enough The Hydrogen Sulphide gas exposure factsheet provides information to help prevent risks of exposure.

Further information

For further information contact or visit some of the sites listed below:

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