Mine Tailings Storage
There are over 30,000 large-scale mines in the world, providing industrialized nations with their minerals and metals. China alone has over 12,000 mines. Mines manufacture massive ecological devastation.
The tremendous amounts of waste rock, sand, and chemicals from mines are termed tailings. Tailings are ‘permanently’ stored behind dams built near the mine. All tailings storage ponds seep, extensively polluting groundwater.
The technical knowledge to build and maintain tailings storage facilities exist, but there has been an inadequate commitment to safe storage, combined with poor management. ~ United Nations Environment Programme
Some tailings lakes are huge. Tailings storage for the Fort Knox gold mine in Alaska is a valley that is home to a toxic lake covering 395 hectares, with 270 million tonnes of tailings.
From 1985 to 2017, there were 139 major tailings dam failures. 44% of them wreaked serious environmental destruction.
The Germano mine in southeast Brazil is exemplary. There are over 300 mineral mines in that area (the state of Minas Gerais), extracting gold, diamonds, manganese, and many other ores and gems. Industrial mining in Minas Gerais dates to the 18th century.
On the afternoon of 5 November 2015, one of the tailings dams at Germano mine broke, discharging 33 million cubic tonnes of iron ore tailings. The slurry flowed down the valley, inundating a nearby village, killing 19 people. The lethal slurry then mixed with the 5th-largest river basin in Brazil, where it polluted all downstream waters. Finally, with no response to contain it, the slurry, having traveled 650 kilometers, dumped itself into the Atlantic Ocean, 17 days after its devastating journey began.
The mudflow from the slurry release destroyed over 1,469 hectares of riparian forest. All aquatic life populations were decimated. The contaminated soil prevents plants from growing back. 37 human population centers were severely affected, including a polluted water supply which cannot be restored.
The Germano tailings dam had been poorly constructed, inadequately maintained, and not monitored. There was no warning system in place in case of a spill. This is typical.
On 25 January 2019, a tailings dam for an iron mine in Minas Gerais broke, unleashing a wave of sludge that killed over 350 people. The toll included hundreds of the company’s own employees, many of them having lunch in the cafeteria, recklessly sited below. This was the 2nd such tailings tragedy for Vale, the iron mine owner, in 3 years.
Tailings dams are prone to failure. Unlike water-retaining dams, tailings dams incorporate inferior materials, including tailings. Further, tailings dams are lackadaisically engineered. Unlike water dams, tailings dams are built incrementally over decades, with unaddressed problems passed on as personnel change. Finally, whereas a water-retaining damn is regarded as an asset, tailings storage is considered a cost, and so the incentive is to minimize the effort and materials put into it.
The US has had the most mine tailings dam failures, followed by China and the Philippines.
The consequences on the civil side and criminal side are very weak around the world. ~ Canadian ecologist Ugo Lapointe