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Remediation of the Giant Mine, one of the most contaminated sites in Canada, is expected to be the most expensive federal environmental cleanup.ANGELA GZOWSKI/The Canadian Press

With a cost estimate of $4.38-billion, remediation of the Giant Mine, one of the most contaminated sites in Canada, is also expected to be the most expensive federal environmental cleanup in the country’s history.

The figure, recently approved by the Treasury Board of Canada, spans costs from 2005 until 2038, when active remediation at the former Yellowknife gold mine is anticipated to end. That includes $710-million the federal government said has already been spent, but does not include costs for long-term care and maintenance.

“It doesn’t bother me so much that it’s going to cost $4-billion to clean up Giant Mine. What really bothers me is that the taxpayer is covering that cost,” said David Livingstone, chair of the Giant Mine Oversight Board.

It indicates the federal government failed to ensure private developers provided financial security to remediate sites. He said while that has improved over time, there will likely be more issues in the future.

“We as a society need to get a better handle on what it costs us to support mining industry and oil and gas industry,” he said. “If the numbers suggest that it’s going to cost more to clean up a site than that site generated in revenue to the Crown, we’ve got a problem.”

There are more than 20,000 locations listed in the federal contaminated sites inventory, from dumps and abandoned mines to military operations on federal land.

Environment and Climate Change Canada says that after Giant Mine, the four most expensive cleanups are the Faro Mine in Yukon, the Port Hope Area Initiative in Ontario, Esquimalt Harbour in British Columbia and Yukon’s United Keno Hill Mine.

More than $2-billion has been spent on the five sites so far, and it’s anticipated they will cost taxpayers billions more in the coming years. Their final price tags are not yet known.

The most recent numbers from the Treasury Board of Canada indicate more than $707-million has been spent on remediation, care and maintenance at Faro Mine, a former open pit lead-zinc mine. Its remediation project is expected to take 15 years to complete and is currently estimated to cost $1-billion, plus $166-million for the first 10 years of long-term operation and maintenance.

Parsons Inc. was awarded a $108-million contract in February for construction, care and maintenance at Faro Mine until March 2026, with the option to extend the contract for the duration of active remediation. The company said the contract could ultimately span 20 years and exceed $2-billion.

In 2012, Ottawa committed $1.28-billion in funding over 10 years for the cleanup of historical low-level radioactive waste in the municipalities of Port Hope and Port Granby, Ont. To date, more than $722-million has been spent on assessment and remediation.

The Port Granby Project was completed earlier this year and has moved into long-term monitoring for hundreds of years. The Port Hope cleanup, which started in 2018, will continue into 2030.

The cleanup in the Esquimalt Harbour seabed in Victoria currently has a budget of $162.5-million. Roughly $214-million has already been spent on remediation and assessment. The Department of National Defence said that may include costs before 2015, when the remediation project began.

Cleanup of United Keno Hill Mine, a historical silver, lead and zinc mining property near Yukon’s Keno City, is estimated to cost $125-million, including $79-million during its active reclamation phase. That is expected to begin in 2023 and take five years, followed by a two-year transition phase, then long-term monitoring and maintenance. More than $67-million has been spent on remediation, care and maintenance at the site so far.

Other costly federal sites that have been cleaned up include the Cape Dyer Dew-Line, 21 former radar stations across the Arctic, for $575-million, the Sydney tar ponds and coke ovens on Cape Breton Island, N.S., for nearly $398-million, and the 5 Wing Goose Bay air force base in Labrador, for $142.9-million.

The 2022 public accounts state the gross liability for the 2,524 federal contaminated sites where action is required is nearly $10-billion based on site assessments. Of the 3,079 unassessed sites, 1,330 are projected to proceed to remediation with an estimated liability of $256-million.

The federal contaminated sites action plan was established in 2005 with $4.54-billion in funding over 15 years. That was renewed for an additional 15 years, from 2020 to 2034, with a commitment of $1.16-billion for the first five years.

Jamie Kneen with MiningWatch Canada said the contamination from Giant Mine highlights the importance of the planning and assessment process for development projects.

“If you don’t actually do any planning around something, you can end up with a pretty horrible mess,” he said. “In this case, it killed people before they started even capturing the arsenic. We don’t want that to happen anymore.”

Five most expensive federal remediation projects

The federal government is responsible for more than 20,000 contaminated sites in Canada.

Here is a breakdown of the top five most expensive environmental cleanups where taxpayers are footing the bill. In some cases, public cost estimates have not been updated for several years.

Giant Mine

Estimated to cost $4.38-billion between 2005 and 2038.

The former gold mine within Yellowknife city limits had several owners during operations from 1948 to 2004. The federal government took responsibility for environmental liabilities in 1999, when Royal Oak Mines Inc. went into receivership.

Cleanup at the site, which spans nine square kilometres, includes demolition of the townsite, freezing underground chambers containing 237,000 tonnes of highly toxic arsenic trioxide dust, filling open pits and treating contaminated water.

Active remediation began in 2021 and is expected to end in 2038. The site will then require perpetual care and maintenance.

Faro Mine

Estimated to cost $1-billion over 15 years.

Located in south central Yukon, it was once the world’s largest open pit lead-zinc mine. It spans 25 square kilometres. Seventy million tonnes of tailings and 320-million tonnes of waste rock were left behind.

The mine was abandoned in 1998 after Anvil Range Mining Corporation declared bankruptcy. The federal government took over the site in 2018.

A remediation approach was selected in 2009 and submitted to the Yukon Environmental and Socio-Economic Assessment Board for review in 2019. The proposal includes covering ore, waste rock and tailings, re-vegetation, diverting clean water away from contaminated sites and treating contaminated water.

Port Hope Area Initiative

Estimated to cost $1.28-billion over 10 years.

Roughly 1.7 million cubic metres of historic low-level radioactive waste in the municipalities of Port Hope and Port Granby, Ont., needs to be managed. The contamination resulted from radium and uranium refining by Eldorado Nuclear Limited, a former Crown corporation, and its predecessors from the 1930s to the 1980s.

Between 2016 and 2020, about 1.3 million tonnes of waste and contaminated soil was removed from the former Port Granby waste management site and relocated to an aboveground mound. That was capped and closed in September, 2021.

The Port Hope project involves the cleanup of about 1.2-million cubic metres of waste at various sites throughout the municipality. It is being relocated and contained in a separate aboveground mound.

Esquimalt Harbour

Estimated to cost $162.5-million. Roughly $214-million has already been spent.

Located in Victoria, contamination accumulated in the harbour seabed after almost 175 years of commercial, military and industrial use.

Nearly 215,000 cubic metres of contaminated sediment and more than 1,000 tonnes of debris has been removed from the sea floor.

United Keno Hill Mine

Estimated to cost $125-million.

United Keno Hill Mines Limited stopped mining in Yukon’s Keno Hill silver district in 1989 due to declining silver prices. While the company tried to resume production in the 1990s, Keno never reopened and was declared abandoned in 2001.

Alexco Resource Corporation purchased United’s former assets in 2006 and continued mining at the site. The company and its subsidiary also took over responsibility for reclamation of historical mining activities and the federal government agreed to pay for remediation. The exact terms of the deal are private. Hecla Mining Company acquired Alexco earlier this year.

The site stretches 150 square kilometres and includes multiple open pits, waste rock dumps and tailings facilities. The reclamation project includes relocating mine waste, constructing water treatment facilities and reclaiming mine workings.

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