Environment Canada says it's exploring 2 new options for proposed Thunder Bay harbour cleanup

Officials with Environment and Climate Change Canada say two new options are being considered for possible remediation efforts to clean up a patch of toxic historical industrial pollution in Thunder Bay's north harbour.

Additionally, one previous proposal capping the estimated 400,000 cubic metres of mercury-contaminated pulp fibre with clean material and a specialized fabric barrier called a geotextile is now off the table, according to Roger Santiago, the head of the federal department's sediment remediation group.

A rebuilt steering committee is taking a fresh look at how the legacy pollution in Thunder Bay's harbour, identified as an "area of concern" under bilateral efforts between Canada and the United States to clean up the Great Lakes, can best be cleaned up. The committee includes representatives from Environment Canada and Transport Canada, Ontario's environment ministry, the Thunder Bay Port Authority and numerous business, municipal, not-for-profit and Indigenous stakeholders.

The five proposals being considered now include:

• Dredging the lake and disposing of contaminated material in a new secure facility,
• Dredging the lake and using existing lagoons on the former mill property for disposal,
• Dredging the lake and transporting contaminated material to an existing facility on Mission Bay,
• Dredging the lake, reconfiguring the mill site lagoons and disposing of contaminated material there,
• Creating a rock berm in Lake Superior, containing about 80 per cent of the contaminated material.

The last two options are new, Santiago said, adding that further study on potential environmental effects is being done on the berm option.

Now, researchers are comparing the new options "with the previous options we looked at back in 2014, so we have a draft report of that work," he told CBC News.

"The consultants were up in Thunder Bay a couple weeks ago and they presented their preliminary findings from those studies," Santiago continued.

"So at this point now, the working group has those draft reports and they are reviewing those to get back to us with comments later in the summer and then to finalize those reports in early fall, along with any additional recommendations ... for additional work that we should be undertaking."

The pollution in the harbour was dumped into Lake Superior during decades of industrial activity. The site was home to a pulp mill that passed through several owners; the current owner of the site itself isSuperior Fine Papers, however a progress report on the ongoing remediation study from Environment Canada shows the company never operated it and the mortgage is currently assigned to a holding company.

The report says the mill closed in 2007.

The polluted patch in the harbour is classified as being most in need of remediation, Environment Canada said.

"The plan at this point is once we've completed updating all five ... sediment management options, then we'll take that back to the public," Santiago said, adding that "would be the final step of information we would need so that the working group could go forward with their recommendation."

After a preferred option is recommended, Santiago said stakeholders will have to sit down to figure out how an actual cleanup plan is drafted, including how it would be funded. Previous estimates pegged cleanup costs in the tens of millions of dollars; Santiago said, given those estimates are at least five years old, new ones will have to be established.

Additionally, complex jurisdictional issues regarding the ownership and management of the site would also need to be worked out.

Open houses to gather public feedback on the existing options are tentatively scheduled for either late fall or early winter, Santiago said, adding that a preferred option is still scheduled to be chosen by 2020.