Thunder Bay: Area of Concern

Thunder Bay, located on the north shore of Lake Superior and one of Canada’s largest inland shipping ports, was identified as an Area of Concern (AOC) in 1987. Today, through the efforts of Environment and Climate Change Canada and its partners, there have been significant improvements at this AOC.

Why it was listed as an Area of Concern

Thunder Bay was designated as an AOC because a review of available data indicated that water quality and environmental health were severely degraded. There has been a long history of discharges into the harbour, primarily from the forest products industry (e.g., pulp and paper mills). Over the years, industrialization, dredging, waste disposal, the release of pollutants, and channelization (channels made in the area) adversely impacted water quality and eliminated a significant amount of fish and wildlife habitat along the waterfront which resulted in 10 of the Great Lakes Water Quality Agreement's 14 beneficial use indicators of ecological quality being deemed as impaired. 

What has been accomplished

Through the combined efforts of Environment and Climate Change Canada, the Province of Ontario, local industry, concerned citizens and other partners, there has been significant improvement to water quality and ecosystem health in the Thunder Bay AOC. 2 of the original 11 beneficial use impairments (BUI) have been re-designated to “not impaired” status: added costs to agriculture or industry; and restrictions on dredging activities.

The 9 BUIs that remain impaired or require further assessment are: restrictions on fish consumption; degradation of fish and wildlife populations; degradation of benthos; beach closings; loss of fish and wildlife habitat, fish tumours or other deformities; bird or animal deformities or reproduction problems; degradation of aesthetics; and degradation of phytoplankton and zooplankton populations. Assessments are underway to evaluate the status of these BUIs.

The environmental improvements in the Thunder Bay AOC are the result of numerous remedial actions. Through the collaborative effort of industry and the Governments of Canada and Ontario, the $20 Million Northern Wood Preservers Alternative Remediation Concept (NOWPARC) project was completed in 2003. The project resulted in 32,000 cubic metres of highly contaminated sediment being contained or removed, treated and reused; and, 5 hectares of fish habitat being created. Assessments of the fish community around the NOWPARC site indicate the area now supports diverse and abundant fish populations.

All remedial actions have been completed for municipal and industrial wastewater treatment. The implementation of federal and provincial pulp and paper regulations and the Province of Ontario’s Municipal Industrial Strategy for Abatement regulations in the mid-1990s resulted in improvements in mill processes and upgrades to wastewater treatment facilities at pulp and paper mills. Upgrades in municipal wastewater treatment were also completed. Together, this resulted in improved water quality, fish habitat, fish populations, and wildlife health.

With funding from the federal and provincial governments, EcoSuperior (a not-for-profit organization) implemented Low Impact Design features in local waterways to mitigate adverse impacts stormwater has on water quality and fish habitat in the AOC. Initiatives like this, and the City of Thunder Bay’s efforts to develop and implement a stormwater management plan, help to mitigate non-point sources of pollution to the AOC.

The federal and provincial governments, working alongside local governments and other agencies completed many habitat rehabilitation projects in the AOC, including:

  • In 1991, increasing the abundance of fish populations by building and rehabilitating fish spawning sites and nursery habitats in the Current River Estuary totaling 1,700 square metres in area
  • In 1993, restoring and creating aquatic habitat in 5 tributaries flowing into Thunder Bay Harbour, such as on the Current River, Kaministiquia River, and McIntyre/Neebing River, and creating island habitat at the mouth of McVicar Creek
  • In 1994, rehabilitating the littoral zone (the area close to the shore) in McKellar River by stabilizing wetlands and also planting more than 4,000 native trees, shrubs and grasses near the mouth of the river, which created 3 hectares of wetland and more natural habitat for wildlife

Progress has also been made to address the beach closings BUI through rehabilitation efforts that include beach regrading, improving drainage systems and removing a portion of the break wall to increase water circulation at Chippewa Beach.

What is left to do

Environment and Climate Change Canada and the Province of Ontario are working with local citizens and community, industry and other government partners to address remaining environmental issues affecting the AOC.

The Remedial Action Plan will strive for further enhancements of fish and wildlife habitat in the AOC. Habitat assessments suggest coastal wetlands and other wetlands are healthy within the AOC relative to those outside the AOC. Riparian zone habitat could be the focus of future restoration work.

Completing the development of a contaminated sediment management strategy for the Thunder Bay North Harbour is also a priority. The area is contaminated with organic materials (wood fibres/pulp) and mercury. Extensive site investigations and an ecological and human health risk assessment have been completed, which represents a $1.5 Million investment with $550,000 coming from Environment and Climate Change Canada. Options for managing the contaminated sediment have been identified, and a 13-member Working Group has been formed to recommend a preferred management option by 2019-2020. The Working Group has representatives from Environment and Climate Change Canada, Transport Canada, Thunder Bay Port Authority, Ontario Ministry of the Environment, Conservation and Parks, local Indigenous communities, the City of Thunder Bay, and area landowners. The public and Indigenous communities are being engaged throughout the process. 


Under the Canada-Ontario Agreement on Great Lakes Water Quality and Ecosystem Health, Canada and Ontario will continue to make significant progress towards remedial action implementation, environmental recovery and restoration of beneficial uses in the Thunder Bay AOC. It is anticipated that actions will be completed beyond 2020.


Efforts in Thunder Bay are undertaken in a partnership between the Government of Canada, other levels of government and non-government groups, including members of the public. 

Undertaking environmental restoration requires a large amount of scientific and technical expertise, local knowledge and hard work. One agency or group cannot engage in such a large task on its own without the help of others.

Listed below are participants that have contributed to efforts in Thunder Bay:

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