World’s Biggest Miners Push to Set New Standards for Dams

World’s Biggest Miners Push to Set New Standards for Dams


Some of the world’s largest miners said they would create a global standard for managing waste dams that will likely include a system for independent reviews of the structures, after one collapsed in Brazil killing at least 179 people.

The International Council on Mining & Metals, which represents 27 large mining companies, said it would establish an independent panel of experts to develop international guidelines, based on current best practices, for its member companies to follow in building and maintaining so-called tailings dams.

The plan so far includes little detail about how such standards would be enforced.

Since several global benchmarks already exist, miners will have to convince the industry’s critics that such standards would improve safety and that those monitoring the risks will have some form of enforcement power.

“They are only a lobbyist for a specific group of miners. They are not a global regulatory body,” Lindsay Newland Bowker, an environmental risk manager in Maine who studies accidents at mining dams, said of ICMM.

The ICMM said that, following the panel’s review, its standards could include a system for independent reviews of tailings facilities.

The Wall Street Journal first reportedclose ties between the owner of the collapsed Brazilian dam,

Vale
SA,

and its inspector, Germany-based TÜV SÜD. A Journal investigation found Vale and its inspectorswere aware of dangerous conditionsat the mine-waste dam months before it collapsed last month but that inspectors, worried about losing Vale contracts, certified the dam as safe.

TÜV SÜD couldn’t immediately be reached for comment and has previously declined to directly address questions of conflict of interest but said that had said there was “heightened uncertainty” about whether the system of safety audits in Brazil provided a reliable declaration of the stability of a dam. TÜV SÜD.

Vale wasn’t immediately available for comment.

A Vale spokeswoman has said previously that TÜV SÜD is an external auditor for the Brazilian company. She didn’t directly address whether the company’s dual consulting-inspecting role presented any conflict of interest.

She said the Brumadinho dam was repeatedly inspected and monitored not only by TÜV SÜD but by other external companies and Vale itself.

“The standard will become the baseline for best practice with the goal for eliminating accidents,” Donald Lindsay, who is chairman of the ICMM and the chief executive of Teck Resources Ltd, a Canadian miner, said on a conference call. There “will be a requirement for every company in the ICMM to follow these standards,” he said.

The ICMM offered few details on how the standards would be policed or how key issues such as independence would be ensured. Some miners said they would need assurances that companies would follow the standards. In a later email, Tom Butler, the ICMM chief executive raised the possibility that members who don’t follow the standards could be thrown out of the group.

The industry group didn’t rule out establishing an independent body to oversee tailings dams globally, although Mr. Butler said it wouldn’t second-guess the review’s outcome. “The aim will be to come up with something credible that is sufficiently independent to close the trust gap that we are facing,” he said.

Tailings Dam Risks

alistair.macdonald@wsj.com

Water

Rate of rise

Water is a tailings dam’s worst enemy. If it saturates the dam walls or the tailings beneath an upstream dam, the whole structure can liquefy and slide. Wetter tailings also travel farther and faster if they escape, causing more destruction.

Upstream tailings dams should be raised slowly, to allow the solid tailings time to dry and consolidate enough to support a new level of the dam.

Weak foundation

Height and angle

An undetected layer of clay or silt beneath a tailings dam can prove disastrous. In addition to being less sturdy than rock or sand, such materials drain poorly, allowing water to silently infiltrate the dam.

The taller the dam, the greater the catastrophe if it fails. The steeper the dam, the greater the risk. For an upstream dam made from tailings themselves, engineers recommend a 25% gradient—flat enough to walk up.

Anglo American PLC

Water

Rate of rise

Water is a tailings dam’s worst enemy. If it saturates the dam walls or the tailings beneath an upstream dam, the whole structure can liquefy and slide. Wetter tailings also travel farther and faster if they escape, causing more destruction.

Upstream tailings dams should be raised slowly, to allow the solid tailings time to dry and consolidate enough to support a new level of the dam.

Weak foundation

Height and angle

An undetected layer of clay or silt beneath a tailings dam can prove disastrous. In addition to being less sturdy than rock or sand, such materials drain poorly, allowing water to silently infiltrate the dam.

The taller the dam, the greater the catastrophe if it fails. The steeper the dam, the greater the risk. For an upstream dam made from tailings themselves, engineers recommend a 25% gradient—flat enough to walk up.

Germany

Water

Rate of rise

Water is a tailings dam’s worst enemy. If it saturates the dam walls or the tailings beneath an upstream dam, the whole structure can liquefy and slide. Wetter tailings also travel farther and faster if they escape, causing more destruction.

Upstream tailings dams should be raised slowly, to allow the solid tailings time to dry and consolidate enough to support a new level of the dam.

Weak foundation

Height and angle

An undetected layer of clay or silt beneath a tailings dam can prove disastrous. In addition to being less sturdy than rock or sand, such materials drain poorly, allowing water to silently infiltrate the dam.

The taller the dam, the greater the catastrophe if it fails. The steeper the dam, the greater the risk. For an upstream dam made from tailings themselves, engineers recommend a 25% gradient—flat enough to walk up.

Lindsay Newland Bowker

Water

Water is a tailings dam’s worst enemy. If it saturates the dam walls or the tailings beneath an upstream dam, the whole structure can liquefy and slide. Wetter tailings also travel farther and faster if they escape, causing more destruction.

Weak foundation

An undetected layer of clay or silt beneath a tailings dam can prove disastrous. In addition to being less sturdy than rock or sand, such materials drain poorly, allowing water to silently infiltrate the dam.

Rate of rise

Upstream tailings dams should be raised slowly, to allow the solid tailings time to dry and consolidate enough to support a new level of the dam.

Height and angle

The taller the dam, the greater the catastrophe if it fails. The steeper the dam, the greater the risk. For an upstream dam made from tailings themselves, engineers recommend a 25% gradient—flat enough to walk up.

Last month’s accident in Brazil has raised questions about whether safety auditors, like the one the dam’s owner Vale SA employed, can be independent when they also compete for consulting fees from the same company.

The dam’s collapse unleashed a torrent of sludge that swallowed an employee cafeteria, offices and nearby homes. Around 131 people are still unaccounted for.

In Brazil, the government has already clamped down on the type of upstream structure that failed.

The ICMM includes

BHP Group
Ltd.

,

Anglo American

PLC and

Glencore

PLC, whose chief executives recently said they would back an independent body to oversee dams. It also includes Vale.

Some global bodies, including the Mining Association of Canada and the World Bank, already have standards for tailings dams, and the ICMM itself has an existing set of guidelines.

BHP, the world’s largest mining company, earlier said it currently follows standards recommended by the Canadian Dam Association. The company said these are widely regarded as the most rigorous in the industry.

— Scott Patterson contributed to this article.

Write toAlistair MacDonald at[email protected]and Rhiannon Hoyle at[email protected]

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