Overview

This report summarizes learnings and recommendations from more than 120 scientific research projects carried out between 2014 and 2021 under the Harmful Pollutants Annex of the 2014 Canada-Ontario Agreement on Great Lakes Water Quality and Ecosystem Health (COA).

Canada and Ontario have been working together for more than 50 years under COA to promote a healthy, prosperous and sustainable Great Lakes Basin ecosystem for current and future generations. This work includes a focus on reducing or eliminating the release of harmful pollutants into the Great Lakes Basin.

Harmful pollutants are chemicals or pathogens that may cause harm to human health or the environment. These can include Chemicals of Concern, identified in the 2014 COA as priority pollutants, as well as other pollutants such as pharmaceuticals, chloride and tire wear compounds. The ten Chemicals of Concern are:

The scientific studies and research projects covered in this report address priorities related to the release of harmful pollutants from industrial, agricultural and wastewater treatment plants into rivers and lakes in the Great Lakes Basin.

Report findings

Key findings from the report include:

  • harmful pollutants continue to reach our lakes through stormwater run-off, industrial and municipal wastewater discharges
  • although levels of legacy pollutants have declined, PCBs and mercury continue to be a concern as they are remobilized from sediment and continue to cause fish consumption advisories
  • additional monitoring is needed to address knowledge gaps on the effects and sources of some harmful pollutants new monitoring tools and chemical analysis called “non-target analysis” provide an opportunity to identify new harmful pollutants that would otherwise not be detected and allow us to take actions to reduce their presence in the Great Lakes Basin
  • more action is needed to manage litter and sources of plastic pollution to reduce the amount of plastics detected in our waterways
  • biological testing continues to be a good complement to chemical analysis as it can show effects resulting from all chemicals present

Results and recommendations

Results from these research projects led to:

  • an improved understanding of pollution sources and releases
  • technological advances for enhanced monitoring and analysis of harmful pollutants in the Great Lakes

Recommendations in the report are driving new research and decision making to deliver on commitments identified under the Harmful Pollutants Annex of the 2021 COA.

The report is also serving as an important resource for the provincial and federal governments by assisting with and improving ongoing program implementation to protect and restore the Great Lakes.

Disclaimer

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