Could the Hungarian tailings dam tragedy happen in Alberta?
Sadly, the tailings dam failure in Hungary is not unique. Every year between two and five of the more than 3,500 tailings dams in the world experience major failures….Could the Hungarian tailings dam tragedy happen in Alberta?
| Document | Responsible Government Department | Availability |
|---|---|---|
| Emergency Preparedness Plan | Dam Safety Section – Alberta Environment | Confidential |
Why have so many tailings dams failed in recent years?
The number of tailings dam failures has doubled in the past 20 years. Advances in mining technology have made it possible to exploit lower grade deposits despite decreasing commodity prices, which means disposing of more rejects and putting more pressure on tailings facilities.
What is tailings dam failure?
On the 22nd February 1994 the Merriespruit tailings dam failed by overtopping as a consequence of heavy rains causing a flowslide (static liquefaction) of part of the embankment (Davies 2002). Small slips had caused the impoundment to close temporarily, and only mine water with small amounts of tailings were deposited.
What caused the Mount Polley mine disaster?
Less than two decades after the Mount Polley mine in British Columbia opened, disaster struck. An investigation into the cause of the spill revealed mine engineers failed to account for glacial silt underneath the tailings containment pond, leading to structural insufficiencies that caused the dam’s collapse.
Why are tailing dams unsafe?
The storage of tailings under water can effectively hinder the chemical reactions that they undergo. However, tailings dams frequently fail, resulting in the discharge of significant quantities of tailings into the natural environment, thereby causing grievous casualties and serious economic losses.
Why are tailings dams notoriously unstable and at risk for failure?
Tailings are typically composed of sand, silt and clay particles that are suspended in a water-based slurry. The fact that tailings may contain chemicals used for mineral extraction makes these failures of particular concern beyond that of a typical dam.
Who owns Imperial Metals?
N. Murray Edwards
Imperial Metals’ majority owner, N. Murray Edwards, currently boasts a net worth of $2.9 billion, making him one of the wealthiest Canadians. Companies owned by Edwards have historically been major donors to the BC Liberals, who governed the province for 16 years until one year ago.
What are tailing ponds used for?
Tailings ponds are engineered dam and dyke facilities used for storage of tailings materials. Tailing ponds are also used to enable water to separate from the tailings. Water from the tailings ponds is recycled back into the extraction process, reducing the use of fresh water from the Athabasca River and other sources.
How does a tailings pond work?
Why are tailing ponds good?
Tailings ponds serve the dual purpose of storing water and tailings. Eventually the solids in suspension settle, which allows the water to be reused several times.
What happens when a catastrophic tailings dam fails?
A catastrophic tailings dam failure can have significant financial and environmental consequences—financial from cleanup and environmental from metals contamination to surface and ground waters, and to soils.
How many tailings dams are there in the world?
There are more than 3,500 tailings dams located around the world (Davies 2002) and between 25,420 and 48,000 large water supply dams worldwide (WCOLD 2000). Yet tailings dam failures (events resulting in the escape of tailings and/or water from the tailings dam) have occurred more frequently than water supply dam failures.
What happened when the Mount Polley dam failed?
The dam failure and its impacts. On Aug. 4, 2014, the tailings dam of Imperial Metals Corp.’s Mount Polley copper and gold mine near Likely, British Columbia, Canada, failed, releasing 7.3 million m 3 of tailings, 10.6 million m 3 of water, and 6.5 million m 3 of interstitial water into the environment.
What happened to the Guadiamar dam in 1998?
The dam failure in April 1998 released approximately 528 million gallons (2 million cubic meters) of pyrite sludge and another 1 billion gallons (4 million cubic meters) of acid water containing high concentrations of heavy metals (zinc, lead, arsenic, copper, antimony, thallium, and cadmium) into the Guadiamar River.
