An Acid-Spilling Mine Turned This Colorado River Bright Orange

By Alissa Walker on at

This time of year kayaks and inner tubes usually crowd the crystal-clear waters of the Animas River, which flows through the western Colorado city of Durango. A couple of nights ago the river was quickly abandoned as nearly 3.8 million litres of wastewater from a local mine seeped in and slowly trickled downstream, eventually colouring the entire river an eerie electric orange.

The wastewater was accidentally spilled by the Environmental Protection Agency as they attempted cleanup work on Gold King Mine, upstream from Durango. The long-abandoned mine had a collapsed entrance which had been known to release contaminated water into a nearby creek, so a crew of workers was installing a pipe to divert the flow. As they dug a hole they realized the wastewater in the mine was higher than they thought. A wall of yellow-orange sludge—4,540 litres per minute—began flowing downstream.

 

As a ribbon of orange made its way downstream yesterday afternoon, the river was closed to recreational use and the city of Durango stopped its intake of water for public consumption. The city’s drinking water quality is not at risk, however, since the river is only a secondary source.

The orange colour was caused not only by the highly acidic water but also the presence of heavy metals like iron, aluminium, cadmium, zinc, and copper, an EPA worker told the Durango Herald. The dramatic shade made for some stunning and scary images of a river turned toxic.

Testing will begin today to see how fish and other wildlife has been affected, with a mobile lab arriving on site to determine the chemical makeup of the spill and decide how to treat it. But really the only fix is time: Officials said that the purification of the river will happen naturally as some of the larger solids settle and fresh water flows from upstream.

Check out the before and after shots of the river to see just how much work there is to do.

[Durango Herald]