Great Lakes water quality agreement: discharges from vessels

An older ship sits docked near a rock break wall. In the distance, the Toronto skyline is hidden behind a clouded sheet of grey

An older ship sits docked near a rock break wall. In the distance, the Toronto skyline is hidden behind a clouded sheet of grey.

Photo: ©

Objective: To protect human health and the environment by preventing harmful, polluting substances from being discharged from vessels operating within the Great Lakes.

This annex consolidates previous entries pertaining to shipping activities under the 1987 Great Lakes Water Quality Agreement into a single annex. It includes a number of commitments to protect the Great Lakes from the discharge of sewage, garbage and harmful polluting substances from vessels and from aquatic invasive species in ballast water.

Various principles will guide work under this annex, such as taking into account standards and guidance issued by the International Maritime Organization (IMO) and implementing domestic laws and regulations for vessel discharges.

Why is action on vessel discharges important?

Shipping activities can affect Great Lakes water quality. This may come as a result of vessels discharging oil, hazardous polluting substances, garbage, wastewater or ballast water.

Commitment to key activities within the 2012 GLWQA

  • Prevent or prohibit harmful discharges from vessels by:
    • preventing the discharge of harmful quantities of oil or hazardous polluting substances;
    • prohibiting the discharge of garbage;
    • minimizing the discharge of cargo residues;
    • prohibiting the discharge of harmful amounts of wastewater;
    • controlling the discharge of sewage;
    • preventing the release of harmful aquatic invasive species and pathogens as a result of accumulation of microorganisms, plants, algae, or animals on ships;
    • preventing harm from anti-fouling systems;
    • preventing the discharge of aquatic invasive species in ballast water;
    • ensuring adequate facilities for receiving, treating and disposing of vessel wastes;
    • reviewing relevant shipping activities to maintain or improve Great Lakes water quality.

Expected outcomes

  • Healthier aquatic ecosystems with reduced threat of impact from aquatic invasive species, oil, and other hazardous polluting substances;
  • Compatible and consistent approach to address vessel discharges within the Great Lakes.
Report a problem or mistake on this page
Please select all that apply:

Thank you for your help!

You will not receive a reply. For enquiries, contact us.

Date modified: