In-water Cleaning of Vessels

Transport Canada is working to protect Canadian waters by limiting the introduction and spread of aquatic invasive species through marine shipping. One of the main ways that invasive species arrive in Canadian waters is from vessel biofouling.

“Biofouling” happens when microorganisms, plants, algae, and animals build-up on structures that are exposed to an aquatic environment, like a vessel’s hull. Vessel’s biofouling can transport foreign species to Canadian waters, or between ecosystems within Canada. These species can then become invasive and harmful in their new environments. This build-up can also increase vessel’s drag, which means it needs to use more power to move. This leads to more fuel consumption and higher operating costs.

Cleaning a vessel in-water to remove this build-up can be an important part of managing biofouling. It’s important to remember that cleaning a vessel in-water could also release organisms and contaminants into the environment. There are new technologies that can help manage these risks by capturing the organisms and contaminants that break-off during cleaning.

Transport Canada is collaborating with stakeholders and the public to develop Voluntary Guidance for Relevant Authorities on In-Water Cleaning of Vessels. Although all vessels should use best practices to manage biofouling, this voluntary guidance will apply to in-water cleaning for vessels that are more than 24 metres long.

Proposed voluntary guidance

The voluntary guidance includes best practices that can be used to manage the risks of cleaning vessels in-water.

The guidance suggests that:

• relevant authorities are responsible for deciding whether service providers should be allowed to operate in their waters and reviewing requests for vessel cleanings on a case-by-case basis
• service providers are responsible for any researching, testing, verifying, and documenting the in-water cleaning technology and coordinating with vessel owners and operators on cleaning requests
• vessel owners and operators are responsible for arranging underwater inspections and preparing all documentation related to biofouling

Overall, the guidance recommends that in-water cleaning is ideally done when only “microfouling” (a build-up of slime on a vessel’s hull made up of tiny organisms) is present, instead of doing it reactively, once a vessel has a build-up of “macrofouling” (an easy-to-see build-up of large organisms like barnacles and grass). Vessels with macrofouling have a higher-risk of transporting invasive species.

That being said, we understand that some vessels may need macrofouling cleaned from its hull. As such, the guidance proposes best practices for cleaning both microfouling and macrofouling, using two methods: clean with capture and clean without capture.

All technology used for in-water cleaning should be tested at a facility that’s approved, certified, and audited by an independent accreditation body. Testing should show that the discharge from cleanings meets all legal requirements in the jurisdiction where cleaning takes place. Technology should also follow all recommendations from the vessel’s coating manufacturer.

The guidance also includes stricter criteria for in-water cleaning with capture technology, as this technology could be used on vessels with higher risks of having invasive species.

Testing the clean with capture technology should:

• confirm that the cleaning unit has enough suction to capture build-up that breaks off 50 cm from the cleaning unit
• confirm that the system has a separation unit that can filter out particles with a diameter of 15 microns, or more
• treat cleaning waste to make sure any organisms are killed (for example, by exposing them to UV light, heat, or chemicals)
  • Systems that have a separation unit that can filter out particles with a diameter of 2 microns don’t need a secondary treatment unit
• remove or neutralize biocides and other contaminants before discharging the cleaning waste, and
• monitor its capture performance in real-time, using sensors or cameras

A vessel should only be cleaned without capture technology if the biofouling build-up:

• is only microfouling, or
• it can be confirmed that it happened locally

If a vessel doesn’t meet this criteria, it should be cleaned using a system with capture technology.

Select draft voluntary guidance to get a copy of the document.

We want to hear from you

Do you have opinions or comments about in-water cleaning or the proposed voluntary guidance? There are two ways to do it, first choose “Register” at the top of the page and then:

1. Join the discussion under the “Have Your Say” tab, or
2. Submit your comments to Transport Canada under the “Submissions” tab.