An estimated one billion litres — or about 264 million gallons — of muck from an Alberta, Canada coal mine broke out of its containment pond on Halloween. The liquid flowed down two creeks and across 25 kilometers from the Obed Mountain coal mine to the Athabasca River, and is now headed downriver.
“There’s actually quite a noticeable change of color [in the river],” said Alberta Environment spokeswoman Jessica Potter. “It’s like muddy water… murky, muddy water.”
Staff from the Alberta Health Services are now analyzing water samples to check if any of the sediments could cause environmental or health damage. The water contained coal dust, clay, mudstone, sandstone, shale and dirt, though the Edmonton Journal quoted an anonymous Sherritt official claiming “the materials in the pond are inert and aren’t toxic to humans or fish.”
According to the Journal, such containment bodies are generally designed so that water runoff from the operations flows into the ponds, and then stays until the sediments settle to the bottom, leaving the water safe to release. Operations at the mine, which is owned by Sherritt International, were actually suspended last November, and it since been undergoing reclamation.
Fortunately, most of the nearby communities don’t draw their drinking water from the river, and the municipal water systems are designed to filter out these sorts of solids, according to Potter. Ten communities were alerted about the spill, including Whitecourt, Athabasca, Hinton, Yellowhead and Woodland counties, and the Alexis Nakota Sioux and Alexander First Nations, and Hinton.
On the opposite end of the energy production life cycle, similar containment ponds are used to hold the toxic coal ash and other waste generated by coal-fired power plants. As of 2010, there were 285 active ponds in the United States, according to a Huffington Post review of federal Mine Safety and Health Administration data.
The American ponds have seen their share of noteworthy spills. In 2008, a spill at the Tennessee Valley Authority’s Kingston plant spilled around 300 million gallons of coal ash sludge across 400 acres of Roane County, Tennessee. Earlier, in 2000, about 250 million gallons of sludge leaked into the waterways of Kentucky and West Virginia from a a Martin County Coal Corp. containment pond, eventually entering the Big Sandy River and the Ohio River. Back in 1972, a dam collapse at another pond near Buffalo Creek, West Virginia, killed 125 people, destroyed 500 homes, and led to the Surface Mining Control and Reclamation Act five years later. A spill in 1967 released 130 million gallons in Virginia, and a 2005 spill sent about 100 million gallons into Pennsylvania and the Delaware River.
All told, there were 22 such spills between 2000 and 2010, though most were relatively small.
In contrast to the sediment from the Alberta coal mine spill, there’s evidence coal ash slurry from power plant spills is toxic: multiple studies show it contains significant levels of carcinogens such as arsenic, and poses “risks to human health and ecosystems.”