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Guidance on the use of exhaust gas cleaning systems (scrubbers) for ports, regional authorities and ships

There are global concerns over the potential impacts of scrubber contaminants on the marine environment. This page has the current guidance on the use of these systems in New Zealand territorial waters.

The Ministry for the Environment supports the use of precaution

The Ministry for the Environment supports the use of precaution by ships operating scrubbers in NZ territorial waters, whilst we undertake further monitoring to address key uncertainties related to the use of these systems.

This guidance will be updated as New Zealand establishes a formal position on the use of equivalents such as scrubbers in our waters, once we have signed up to Annex VI.

While this guidance is non-statutory, we encourage industry to implement the following measures.We request that all ships carrying scrubbers and operating in New Zealand’s territorial waters follow any measures as advised by the relevant port and regional authorities.

This may include being asked to avoid discharging scrubber washwater close to shore by utilising alternate options such as:

  • preparing for entry into New Zealand waters by carrying compliant low sulphur fuel in order to use when operating in sensitive environments, as identified by the relevant regional authorities
  • operating closed loop scrubbers in zero discharge mode and retaining any waste sludge on board until able to dispose of at the next available port facility
  • discharging any open loop scrubber washwater outside territorial waters.

Work happening under the IMO in relation to scrubbers

In 2019, the IMO requested that the United Nations’ Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP) establish a task team. The task team undertook a review of all relevant scientific literature and oversaw a modelling study to assess the impacts of discharges from scrubbers on the environment.

In February 2020 GESAMP provided the IMO with a report on the outcomes of this work at a meeting of the IMO's Pollution Prevention and Response (PPR) Sub-Committee. This meeting approved the start of work to evaluate and harmonise rules and guidance on scrubbers, and updated the existing guidelines on their use. The updated guidelines are yet to be adopted by the IMO’s Marine Environment Protection Committee (MEPC).

The work to be undertaken by GESAMP will address concerns over the potential negative impact on the marine environment. The Ministry for the Environment will continue to monitor the progress and outcomes of this and other international work on the use of scrubbers.

Find out more about Annex VI and our marine environment

The new Annex VI sulphur limit [International Maritime Organisation website]

Current IMO guidelines on the use of scrubbers (PDF, 374 KB) [International Maritime Organisation website]

Our activities at sea are affecting the marine environment, see Issue 3 in Our Marine Environment 2019

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