Mercury Contamination in Sediment of Thunder Bay, Ontario Harbour Awaits Clean-up

As reported in TB News Watch, the recommendations in a clean-up report of mercury in Thunder Bay, Ontario harbour have yet to be acted upon.  It has been more than three years since a consultant’s report identified options for the management of 400,000 cubic metres (14 million cubic feet) of mercury-contaminated sediment.

Thunder Bay is located at the northwest corner of Lake Superior and has a population of approximately 110,000.  It

The source of the mercury in the sediment was industrial activity along Thunder Bay’s north harbour for over 90 years including pulp and paper mill operations.  The sediment is contaminated with mercury in concentrations that range from 2 to 11 ppm at the surface of the sediment to 21 ppm at depth and ranging in thickness from 40 to 380 centimeters and covering an area of about 22 hectares (54 acres).

Approximate Area of Contaminated Sediment in Thunder Bay Harbour

The preferred solution in the consultant’s report was to dredge the sediment and transfer it to the Mission Bay Confined Disposal Facility (CDF) at the harbour’s south end.  That came with an estimated cost of $40 million to $50 million, and was considered the best choice based on factors such as environmental effectiveness and cost.  The consultants also looked at other options, including building a new containment structure on the shoreline adjacent to the former Superior Fine Papers mill.

Jim Bailey, a spokesperson for the Thunder Bay Remedial Action Plan, a public advisory committee that is partially funded by Environment Canada and the Ontario Government and oversees monitoring of the harbour pollution, says no solution has been chosen as yet, and there is no money for doing the work.

“One of the holdups is identifying a lead organization or agency to lead this cleanup.  Without a lead, obviously the project can’t go forward, so that is one of the sticking points,” Bailey said in an interview with tbnewswatch.com.

Contaminated Sediment Dredged from Thunder Bay Harbour

Thunder Bay RAP members have recently explored the feasibility of getting the contaminated area added to a federal list of contaminated sites, which might make its cleanup eligible for government funding.

The sediment site is adjacent to the mouth of the Current River, and has been described as layers of “pulpy” material up to four metres thick in some spots.

Bailey said being added to the federal list is one of the keys to getting closer to a cleanup, but the project would still require a cooperative effort involving a number of organizations.

The preferred option for disposal at the Mission Bay CDF near Chippewa Park seems unlikely to come to fruition in any case.

“That’s been used for decades to dispose of sediment collected for navigational dredging. It was never designed, to my knowledge, for contaminated material,” Bailey said.

He added that the Fort William First Nation has also made it clear that it doesn’t want to see the contaminated material disposed of near their community.

According to Bailey, the federal government is the legal custodian of the harbour bottom, but “at this point, Transport Canada has not been fully engaged in this process. Work needs to be done to hopefully get them engaged,” he said.