Great Lakes water quality agreement: chemicals of mutual concern

Commercial plant in Sarnia Ontario

Commercial factory plant with tall smoke stacks, located across the water, close to the shoreline.

Taken by: Carole Swinehart, Michigan Sea Grant Extension.

Credit: United States Environmental Protection Agency Great Lakes National Program Office.

Objective: To eliminate or reduce harmful chemicals in the Great Lakes in order to reduce future costs associated with water treatment and treating illnesses related to chemical exposure, while improving Canadians' quality of life and better protecting the environment.

The Chemicals of Mutual Concern Annex consolidates all commitments regarding chemicals and replaces the previous, static list of chemical substance objectives with a new binational process for identifying chemicals of mutual concern.

Under this annex, Canada and the United States commit to developing binational strategies for addressing chemicals of mutual concern. These strategies may include research, monitoring and surveillance actions, as well as pollution prevention and other control mechanisms and actions.  Both countries also commit to monitoring and reporting on progress towards implementing these strategies.

Canada and the United States continue to recognize the need to manage chemicals of mutual concern by implementing measures to reduce or eliminate their releases into the environment, including, as appropriate, measures to achieve virtual elimination and zero discharge. Furthermore, both countries also recognize that a life-cycle management approach is important for addressing chemicals of mutual concern. This means that the environmental impacts at all stages of a chemical’s life-cycle -- from import or manufacture, through use, re-use and disposal -- are recognized and managed appropriately.

Why is action on chemicals of mutual concern important?

Some chemicals in the Great Lakes basin ecosystem continue to pose a threat to human health and/or the environment. Action in both Canada and the United States is necessary in order to ensure that these “chemicals of mutual concern” are addressed.

For more information on what the Government of Canada is doing to assess and manage chemical substances across Canada, please visit

Commitment to key activities within the 2012 Great Lakes Water Quality Agreement

  • Identify chemicals of mutual concern that originate from anthropogenic (human) sources, and that are agreed to by both countries as being potentially harmful to human health or the environment;
  • Target these chemicals of mutual concern for action by preparing binational strategies and coordinating the development and application of domestic water quality standards, objectives, criteria and guidelines, as appropriate;
  • Reduce anthropogenic releases of chemicals of mutual concern and products containing chemicals of mutual concern throughout their entire life cycles;
  • Promote the use of safer chemical substances and the use of technologies that reduce or eliminate the uses and releases of chemicals of mutual concern;
  • Continue progress toward the sound management of chemicals of mutual concern using approaches that are accountable, adaptive and science-based;
  • Monitor and evaluate the progress and effectiveness of pollution prevention and control measures for chemicals of mutual concern and adapt management approaches as necessary;
  • Regularly exchange information on monitoring, surveillance, research, technologies, and measures for managing chemicals of mutual concern;
  • Coordinate and collaborate with various stakeholders on science priorities, research, surveillance and monitoring activities in the Great Lakes basin ecosystem; and
  • Report on progress toward implementation of this Annex every three years through the Progress Report of the Parties. 

Expected outcomes

  • Identification of chemical substances of mutual concern for which Canada and the United States will take cooperative and coordinated actions; and
  • Reduction or elimination of the uses and/or releases of these chemicals of mutual concern.

Levels of persistent toxic and other harmful chemicals have been significantly reduced, and unlike in the past, today numerous regulatory and non-regulatory programs exist for effectively managing chemical substances at the federal, state, provincial and local levels.

Some chemicals continue to pose a threat despite reductions in both uses and releases, for example fish tissue concentrations of chemicals such as mercury and polychlorinated biphenyls (PCBs) remain at levels requiring consumption advisories in some regions of the basin.

Emerging classes of chemicals of potential concern, including pharmaceuticals, personal care products and synthetic musks could adversely affect the health of the Great Lakes basin ecosystem.

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