‘To prevent more dam spills, you have to spend money’

AS miners globally review the way they store waste after another horrific dam spill, the solution may be as simple as it is dramatic: spend a lot more.

Images of sludge spewing into towns and rivers could be a thing of the past if mines use different types of storage – like removing water or building on more stable ground. While that can be as much as 10 times costlier for companies already squeezed by slumping prices, the cost is much higher when things go wrong.

The clean-up bill for the November 5 spill at the Samarco iron-ore venture in Brazil, owned by BHP Billiton and Vale, will probably exceed $1 billion (R14.3bn), said Deutsche Bank.

“A failure is a lot more expensive than doing it right,” said Dirk van Zyl, professor of mining engineering at the University of British Columbia and an expert on a panel into a dam spill in Canada last year.

The Samarco breach, which propelled about 13 billion gallons of mud into communities below, comes a year after Imperial Metals’ Mount Polley mine in Canada also dumped billions of gallons into lakes and rivers. A common trait in the two cases was the waste’s fluidity.

‘Thorough review’

Samarco says its dams were deemed safe in a July inspection and that it’s too early to determine reasons for the spill. On Monday, BHP chief executive Andrew Mackenzie said the company was “carrying out a thorough review of all of our dam facilities of scale”. On the same day, Vale said it was open to improvements, even after concluding its other installations, which use state-of-theart safety practices, were fully compliant.

Tailings are the ground rock and effluent left after milling. And when it comes to storage, the dryer the better, said Van Zyl. Dry-stack tailings facilities, used in Chile where earthquakes are common, can cost 10 times more than so-called upstream ponds, he said.

The next best option, building storage on virgin ground and limiting the amount of water, could cost twice as much.

Still, those higher investment and operating costs pale next to the expenses associated with a catastrophic accident.

“When you allow economics to be the primary driver, we’re going to see more safety-related incidents,” said David Chambers, president of the Center for Science in Public Participation, a non-profit group based in Bozeman, Montana.

Alberto Sayao, a civil engineering professor at the Catholic University in Rio de Janeiro and a board member of non-governmental organisation Brazilian Dam Committee, said whatever the cause, there was no doubt the damage from both breaches would have been much less had the tailings been less fluid. – Bloomberg BRAZILIAN miner Samarco said on Tuesday it was conducting real-time monitoring and emergency repairs on two of its tailings dams. The dams were damaged in the wake of the November 5 collapse of another dam which killed 11 people and left 12 missing.

Officials of Samarco, an iron ore venture owned by miners Vale and BHP Billiton, said on Tuesday the company’s Santarem dam was most at risk of collapse and its teams were racing to transport 500 000 cubic metres of stone to shore it up.

Samarco’s operations director Kleber Terra said he expected repairs to Santarem to take 45 to 90 days.

But a local weather forecaster A BHP Billiton and Vale joint venture in Brazil is facing its first civil lawsuit after a dam collapse on November 5 that buried a town and contaminated the region’s main river.

Pedro Eduardo Pinheiro Silva, a lawyer who represents a community association in another state, filed the case on Monday, according to the Minas Gerais court website.

Silva is demanding that joint expected heavy rains in the region on Tuesday.

Jose Vasconcelos, civil engineer at the company, said Santarem had been overrun by about 40 million cubic metres of mud and water released after the collapse of the Fundao dam above it.

He estimated that 20m cubic metres of mud and mine debris had settled in the valley below, but about 5.5m cubic metres remained contained by the Santarem dam.

Soon after the collapse of Fundao, the company reported that Santarem had also given way. Inspection officials later discovered, however, that Santarem’s dike was intact but had suffered considerable damage. – Reuters venture, Samarco Minerãçao, pay 10 billion reais (R37.5bn) as compensation for environmental damages.

Silva is based in Bahia but said Brazilian law allowed him to file a case in another state. The judge assigned to the case is Rosilene Sousa Ferreira.

According to the court website, the case number is 0060017-58.2015.4.01.3800. – Bloomberg