Peninsula Harbour

The International Joint Commission (IJC) first identified peninsula Harbour as an Area of Concern (AOC), in 1987. Peninsula Harbour’s Area of Concern is located approximately 290 km from Thunder Bay on the north shore of Lake Superior. The AOC is comprised of two regions: Peninsula Harbour and a portion of open Lake Superior immediately south of the Peninsula; it is roughly bounded by the watershed of the harbour and Pebble Beach, includes the Town of Marathon and extends four kilometers into Lake Superior.

In 1991, Marathon community members came together to form a Public Advisory committee, which assisted federal and provincial agencies in developing the first stage of the RAP for Peninsula Harbour. This plan was developed to identify environmental problems and determine sources of pollution in the AOC.

The harbour was identified as an AOC as a result of problems associated with:

bacterial contamination
aesthetic impairment
degraded fish and benthic communitied
high levels of toxic contamination (i.e. mercury and PBCs) in fish and bottom sediments.



Peninsula Harbour Remedial Action Plan Timeline

1991: The Stage 1 Remedial Action Plan (RAP) Report for the Peninsula Harbour AOC identified 6 beneficial uses as “impaired”, 11 as “not impaired” and 2 as “requiring further assessment”.

Over the last few years Environment Canada and the Ontario Ministry of the Environment have been working towards the goals identified in the Peninsula Harbour RAP. This has involved characterizing the extent of environmental risk from mercury and polychlorinated biphenyl (PCB) contamination of harbour sediments, as well as monitoring and assessing trends in fish and wildlife health in the AOC.

The complete Environmental Risk Assessment for Peninsula Harbour, prepared by Environ Inc. can be accessed here.

Peninsula Harbour Area of Concern Sediment Capping Project

Elevated levels of mercury and PCBs accumulated in the Jellicoe Cove portion of Peninsula Harbour adjacent to a former pulp mill. The source of harbour mercury was a chlor-alkali plant which at one time operated beside the pulp mill.  To create clean habitat for plants and animals and to accelerate natural recovery, Environment Canada and Ontario Ministry of the Environment put in place a project to cap this contaminated sediment with clean sand. The project was completed during the summer of 2012. The integrity of the cap and “re-colonization” of the area by bottom dwelling organisms, including plants, will be monitored for the next 20 years. The capping project is the last major action required to address environmental concerns in Peninsula Harbour.

View an online presentation, including photos, about the capping project.

View photos of the project taken during a public tour organized by the Peninsula Harbour Remedial Action Plan.

Share This!