Utah is well-known as a mining state; the industry has a long history here dating back to the mid-1800s. Silver, gold, lead, copper and zinc were among the first metals excavated in the Beehive State, and mining for coal, hydrocarbons and other minerals has also contributed to Utah’s economic and social growth. Famously, the state is home to the Bingham Canyon Mine, among the largest and deepest open-pit mines on Earth.
Various types of mining leave behind tailing ponds – these bodies of water that essentially serve as disposal facilities for the by-products of mining – slurry from tar sands mining being one example. Tailing ponds make use of the fact that many solids – at least those extracted through mining – weigh more than water: sedimentation takes place, with heavier particles settling at the bottom of the pond. According to an estimate from 2000, there are around 3,500 active tailing ponds worldwide.
The use of tailing ponds is not without its benefits. For example, toxic fine tailings used to separate various minerals and heavy metals from rocks are stored in the ponds, with the dangerous particles thus prevented from being carried through the air to cities and towns where they might impact on human health. However, such uses notwithstanding – and regardless of how colorful they may look in these pictures – tailing ponds also pose environmental threats that are hard to ignore.
For one, harmful pollutants in the wastewater can seep into groundwater or contaminate rivers, particularly if a tailing pond overflows. Tailing ponds can thus have an adverse effect on human settlements over a long period of time, and local wildlife is also thought to be at risk. According to some sources, wild birds and large mammals are liable to be drawn to the ponds as they might a natural pool, oblivious to that fact that the sludge might contain poisonous minerals such as arsenic, mercury or cyanide.
Moab Tailings is a uranium-waste tailing pond in Utah at the site of the largest uranium deposit in the US, discovered in 1952. At one point, the pile of tailings at the mine reached a height of 90 feet (27m). The mine was eventually closed and the unlined tailing pond capped in 1984. End of story? Unfortunately not. Fish in the adjacent river have had to deal with the deadly effects of the ammonia pollutants that have leached into the river. After deferring a decision for years, in March of 2010 the Department of Energy announced that it had moved 1 million tons of the waste. For the remainder, the deadline is 2028.
Many other environmentally concerning tailing ponds can be found in Canada and Venezuela due to the large quantities of oil sands in those countries. Also known as tar sands, these petroleum deposits consist of a mixture of sand, clay, water and bitumen, a form of extremely heavy crude oil.
Oil sands had not been considered part of the world’s oil reserves until relatively recently because oil wells were easier to exploit. However, with higher oil prices and better technology available – meaning bitumen can be profitably extracted and processed – oil sands mining looks as though it is here to stay. And, according to recent reports, the first US tar sands mine could open in Utah soon.
According to Greenpeace Canada, the water pollution and water wastage caused by oil sands mining is massive. Each cubic meter of bitumen produces 3-5 cubic meters of wastewater in the form of tailings. Greenpeace says that the tailing ponds are so humongous that they can actually be spotted from space by the naked eye.
What’s more, petroleum byproducts are known to kill the microorganisms in rivers and wetlands. Say Greenpeace: “Scientists state that the most dangerous contaminant in tar sands tailings water is naphthenic acid, a natural constituent of petroleum that becomes dissolved and concentrated in the hot water used to process the tar sands.”
Continued exposure to naphthenic acid and other tar sands tailing products can have serious consequences on the health of humans and animals alike. Liver problems and brain hemorrhaging can occur; birds end up deformed; and increased instances of cancer and multiple sclerosis have been observed in communities where tar sands mining has been growing apace. The First Nations community of Fort Chipewyan in Alberta, Canada, for example, is downstream from some of the largest tar sands projects. Its citizens have had to find out the hard way why rates of cancer are higher than normal in their community, which is situated in a region where tailings are believed to have seeped into the groundwater.
Even the mining companies themselves admit to some of the detrimental effects of tailing ponds, even if taking responsibility for the hazards to human health just mentioned is a step too far. The Canadian Association of Petroleum Producers (CAPP), for example, concedes that “the tailing ponds created are large and impact the landscape” and that “[r]eturning a tailings pond to a sustainable landscape takes many years.”
According to CAPP, efforts are underway to decrease the size of tailings ponds and the time it takes to turn them back into livable sites. Thickeners added to the tailings, for instance, can aid in recapturing the water from them, thus wasting less water and reducing the sizes of the ponds.
Another new approach is to capture carbon dioxide and mix it with silts in the tailings, causing the formation of a solid mass that allows the silts to settle faster. This allows water to be recycled while still hot, reducing greenhouse gas emissions, tailing pond sizes, and the energy expenditure that would be needed to reheat the water. Whether such measures serve as prevention or cure for the ills of tailing ponds remains to be seen.
As necessary as some mining processes may be – and as beautiful as their tailing ponds appear in these images – they are far from sustainable. Yet, with our ongoing thirst for oil together with the need for other resources like minerals and metals in spite of dwindling resources, tailing ponds show little sign that they will disappear any time soon. Let’s hope that research into mining methods produces more favorable alternatives, and that, one day, colorful pools such as these are attractive-looking features we can do without.