Renewed Thunder Bay Harbour Cleanup Effort
Posted on: February 15, 2019
This undated photo shows the Thunder Bay North Harbour site when the adjacent mill was in operation (mill since demolished). Richardson’s grain elevator and a ship berthed at the shipyards, now owned by Heddle Marine, are visible to the right in the picture. Photographer unknown.

Strong Interest in Harbour Cleanup

On February 5th, approximately 40 people attended an open public meeting at Lakehead University hosted by the Public Advisory Committee to the Thunder Bay Remedial Action Plan (PAC). At the meeting, potential options were presented for cleanup of contamination in the northern portion of Thunder Bay Harbour near the mouth of the Current River. The main contaminant of concern in this area is mercury, which is contained within some 400,000 cubic meters of pulp material that is up to 4 meters thick in sections and sits on the harbour floor. The pulp material was expelled from the former mill that, until its recent demolition, was situated on the harbour shore near this contaminated harbour area.

Samuel Pegg of the North Shore of Lake Superior Remedial Action Plans office at Lakehead University provided background information on this Thunder Bay environmental “Area of Concern,” one of several around the Great Lakes. A presentation about North Harbour cleanup was provided by Tera Yochim Hope of Transport Canada (TC) (owner of the harbour bottom at the site in question, other than any private water lots, and at federally designated ports across Canada) and Roger Santiago, sediment remediation specialist for Environment and Climate Change Canada. Ontario Ministry of the Environment, Conservation and Parks‘ Great Lakes Advisor Dawn Talarico clarified points that arose concerning the former mill site. Dr. Rob Stewart of Lakehead University’s Department of Geography and the Environment facilitated the session, which included questions from the audience.

Cleanup Options Fall Into Two Main Groupings

Presenters pointed out that potential options for cleanup could be grouped into two main categories:

A) on-site or near-site containment

B) transport 12 km across the harbour by barge and disposal at the Mission Bay Confined Disposal Facility (CDF) — This facility is located near Chippewa and is comprised of a series of large cement cells with entryways through which tugs and barges can enter to dispose of material. The Mission Bay CDF is managed by the Thunder Bay Port Authority and has already operated for decades, acting as a deposition and containment facility for dredged material from navigational dredging for harbour shipping. The facility has abundant capacity, even beyond the material from North Harbour.

Presenters noted that each of the two main categories of options described above have several variations. In case A), they said that on-site/near-site options could potentially include deposition of the contaminated material in the effluent lagoons associated with the former mill, a containment cell or large “box” in the contaminated area, or a berm surrounding a larger area — the area of highest contamination.

As for case B), with disposal at the Mission Bay CDF, presenters noted that due to the nature of the contaminated material, further study would be required to determine whether modifications or enhancements to the facility would be necessary. Such modifications could include construction of a smaller cell within one of the larger existing containment cells, at the CDF. The smaller cell could be specially designed and built to hold mercury contaminated material from North Harbour.

How Have Other Great Lakes Sites Been Cleaned Up?

By way of comparison, another Great Lakes site with serious contamination issues is Hamilton Harbour. This site was severely impacted by the steel industry. The basic concept underlying Hamilton’s “Randle Reef” environmental project is quite simple; that is to “box-in” the area of highest harbour contamination with steel sheet piling and then scoop any remaining contaminated material located outside the box into the box, which could then be sealed to create a long-term containment unit.

Presenters pointed out that in the Thunder Bay North Harbour situation, the various options would be examined by the Sediment Management Options Working Group, who would recommend a preferred option. Additionally, they pointed out that further research was necessary on a number of aspects for the intended project. They explained that detailed engineering, design and costing would come later in the process, while initially, only cost estimates would be made in order to compare options. Presenters said that public input would be integral to the process and that public engagement in this regard could continue next winter.


This 2013 photo shows an excavator on a barge undertaking work to quantify the nature of the contaminated pulpy material that sits up to 4 meters thick on the Thunder Bay North Harbour floor over an area of some 26 hectares or 64 acres. Photo: Environment and Climate Change Canada

Public “Q and A”

Attendees at the session raised a number of questions ranging from the impact of the project on future economic development through to the potential for added costs if underwater debris like logs and cables are encountered during dredging. Presenters said they were very aware of these concerns. They also affirmed that ongoing monitoring and maintenance of the site upon project completion was a key aspect. They said that due to these considerations, clarification of site ownership was a pivotal factor in putting together the project, especially since some on-site and near-site cleanup options might straddle land presently held by two different owners. Presenters said that the City of Thunder Bay was part of the Sediment Management Options Working Group and might be able to assist when zoning for future use of the area is considered.

A question was raised as to whether only the contaminated pulp material would be dealt with or if contaminated sediment on the harbour floor would also be addressed. Presenters answered that the project would include the bottom sediment and estimates of overall volume would need to include this material.

When asked whether incineration of the contaminated pulp was a viable option, presenters answered that this option had already been examined and was deemed to be ineffective, largely due to the high costs of dewatering. They said further research would be done in this regard because incineration technology has advanced over time since eliminating the option.

The option of depositing the contaminated material on an upland portion of the former mill site was also broached. Presenters pointed out that a permitted landfill existed on the mill site but that it was full or even over capacity. They explained that, in 2015, material dredged from the mill’s harbour-side effluent lagoons had been placed in the upland former mill landfill. The process of developing another permitted landfill on the site was described as being especially arduous and costly, likely making some of the other options more cost-effective.

Questions about bioaccumulation and the potential impacts of the contamination on aquatic and other organisms were also asked. Presenters answered that questions such as these had been answered in the 2013 Franz Environmental Report, which documented various impacts to aquatic organisms, animals and human health, concluding that cleanup was warranted. They said that peer review of this report would be undertaken.

Working Group Broadens Membership

The Sediment Management Options Working Group is currently responsible for developing solutions at North Harbour and has added important participating organizations to its ranks, but groups have been working toward resolving the North Harbour situation since before it was formed. The Public Advisory Committee to the Thunder Bay Remedial Action Plan (PAC) has been pushing for cleanup for years and one of their fundamental tenets is open communication with the public about environmental issues in Thunder Bay Harbour, including North Harbour contamination.Tera Yochim Hope of Transport Canada pointed out that a previous committee, the North Harbour Working Group, had also worked to address the North Harbour situation and included federal and provincial government agency representatives, as well as former mill owners. The Thunder Bay Port Authority attended meetings of this group as “observer.”

The current Sediment Management Options Working Group has been broadened with several additional organizations now participating. The most important addition is Transport Canada, the owner of the harbour bottom at the site in question. This change in group composition is significant because carrying out cleanup without the participation of the owner would have been difficult, if not impossible. Transport Canada has stated publicly, on a number of occasions, that they are committed to cleanup. The Public Advisory Committee to the Thunder Bay Remedial Action Plan (PAC) is also represented on the new working group.

The North Harbour Sediment Management Options Working Group is comprised of representatives from the following organizations:


This 1977 photo shows the mill and effluent lagoons adjacent to the North Harbour site. Photo: Ontario Ministry of the Environment, Conservation and Parks

Next Steps for North Harbour

According to representatives of the Sediment Management Options Working Group, technical studies, clarification of site ownership and further public engagement will continue through spring 2020. Once these activities have been completed, the working group will recommend a sediment management option to senior management at Transport Canada, the Thunder Bay Port Authority, Environment and Climate Change Canada and the Ontario Ministry of the Environment, Conservation and Parks.

Links:


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