Great Lakes: Areas of Concern

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Objective: To restore water quality and beneficial uses of the ecosystem by cleaning up severely contaminated and degraded locations around the Great Lakes.

What are Areas of Concern?

These are locations within the Great Lakes identified as having experienced high levels of environmental harm. 

Under the 1987 Great Lakes Water Quality Agreement between Canada and the United States, 43 such areas were identified, 12 of which were Canadian and 5 of which were shared binationally. 

The 2012 Great Lakes Water Quality Agreement reaffirms both countries’ commitments to restoring water quality and ecosystem health in Great Lakes Areas of Concern.

Map of Canadian and U.S. Areas of Concern

The map shows the location of 43 Areas of Concerns around the Great Lakes basin - 12 are in Canada, 26 are in the United States, and 5 are shared by both countries. The international boundary between Canada and United States runs through the middle of the lakes. The map also shows the boundary of the Great Lakes watershed.

Canadian Areas of Concern on Lake Superior are: Thunder Bay, Nipigon Bay, Jackfish Bay (in Recovery), and Peninsula Harbour. The St. Marys River is a binational Area of Concern shared by Canada and the United States. On Lake Huron, Canadian Areas of Concern are: Spanish Harbour (in Recovery), Severn Sound (delisted), and Collingwood Harbour (delisted). The St. Clair River and Detroit River are binational Areas of Concern shared by Canada and the United States. On Lake Erie, Wheatley Harbour is the only Area of Concern and it has been delisted. Niagara River is a binational Area of Concern shared by Canada and the United States. On Lake Ontario, Canadian Areas of Concern are: Hamilton Harbour, Toronto and Region, Port Hope Harbour, and Bay of Quinte. The St. Lawrence River is a binational Area of Concern shared by Canada and the United States.

Areas of Concern in the United States on Lake Superior are: St. Louis Bay/River, Torch Lake, and Deer Lake (delisted). Areas of Concern in the United States on Lake Michigan are: Manistique River, Menominee River, Fox River/Southern Green Bay, Sheboygan River, Milwaukee Estuary, Waukegan Harbor, Grand Calumet River, Kalamazoo River, Muskegon Lake, and White Lake (delisted). The Saginaw River and Clinton River Areas of Concern are in the United States on Lake Huron. Areas of Concern in the United States near Lake Erie are: Rouge River, River Raisin, Maumee River, Black River, Cayuhoga River, Ashtabula River, Presque Isle Bay (in Recovery), and Buffalo River. Areas of Concern in the United States on Lake Ontario are: Eighteenmile Creek, Rochester Embayment, and Oswego River/Harbor (delisted).

Why is action needed?

Cleaning up Areas of Concern contributes to the environmental, social and economic well-being of local communities and to improving water quality and ecosystem health throughout the Great Lakes.

What is the Government of Canada doing?

Since 1987, the Government of Canada has supported local action to clean up Areas of Concern. Presently, the Government of Canada provides $8 million per year to fund local cleanup actions in Areas of Concern. This support has been ongoing since 2010, and adds to a previous one-time commitment of $48.9 million to remediate contaminated sediments in Areas of Concern.

This money has been put to good use. Work has been completed in five Canadian Areas of Concern, and by 2019 we anticipate being able to complete all required remedial actions in a further five Canadian Areas of Concern: Nipigon Bay, Niagara River, the Bay of Quinte, St. Lawrence River (Cornwall) and Peninsula Harbour. To date, we have:

  • cleaned up and confirmed restoration of water quality and ecosystem health in three Areas of Concern - Severn Sound, Collingwood Harbour and Wheatley Harbour - which allowed the Government of Canada to remove these sites from the list of Areas of Concern
  • completed all clean-up actions in two Areas of Concern - Spanish Harbour on Lake Huron and Jackfish Bay on Lake Superior - allowing these sites to be designated as Areas of Concern in Recovery, which means that all actions are complete and the areas now need more time for the environment to recover naturally.

To date, over 900 restoration projects have been completed by Environment and Climate Change Canada and community partners in the Areas of Concern. With financial and scientific support provided by Environment and Climate Change Canada, these projects were undertaken at the community level and they have enhanced water quality, restored fish and wildlife populations and habitats, improved management of municipal waste waters, and investigated and developed options to manage contaminated sediments in the Areas of Concern. These projects have served to remediate environmental quality at the local scale, leading us ever closer to completing all required remedial actions.

Contaminated sediment management projects have been completed in the St. Lawrence River (Cornwall), Niagara River, Detroit River, Bay of Quinte and the Peninsula Harbour Area of Concern.

Randle Reef in the Hamilton Harbour Area of Concern is the largest Canadian contaminated sediment site in the Great Lakes, and clean-up is now underway. This project is a major step in the process to restore Hamilton Harbour and remove it from the list of Areas of Concern. The project will improve water quality and make it safer to consume fish caught in the harbour. When completed, current restrictions on navigation will be removed and economic returns will be generated through the creation of valuable port lands. The estimated cost of the Randle Reef sediment remediation project is $138.9 million. In addition to the $46.3 million in funding from the Government of Canada, the Province of Ontario has committed to provide $46.3 million, and $14 million is being contributed by the City of Hamilton, $14 million by U. S. Steel Canada and $14 million by the Hamilton Port Authority, as well as $2.3 million from the City of Burlington and $2 million from Halton Region.

How can you get involved?

There are many community and municipal groups engaged in cleaning up Areas of Concern in their area. The success of many of the projects undertaken are in large part the result of enduring partnerships at binational, national, provincial and local levels. Without the dedicated effort and commitment of all of our partners, we could not have accomplished all that we have in these areas. If you are interested in participating in your area, please contact Environment and Climate Change Canada via email at

To see more specific information on individual Areas of Concern, click on the appropriate link below:


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