Story highlights A federal cleanup crew accidentally caused a big, and potentially hazardous, mess in Colorado.

Officials believe the mine waste carried heavy metals, mainly iron, zinc and copper, from the mine into the Animas River.

(CNN) A federal cleanup crew accidentally caused a big, and potentially hazardous, mess in Colorado, according to the Environmental Protection Agency.

An estimated 1 million gallons of wastewater spilled out of an abandoned mine area in the southern part of the state on Wednesday, turning the Animas River orange and prompting the EPA to tell locals to avoid it.

"When I first saw it, I was speechless, [the river] didn't look real," said Durango, Colorado, resident Ian Lucier. "But in person, it truly looks like the river was turned into carrot juice."

Accounts of the spill's striking appearance flooded social media as the waste pushed its way downriver. Lucier posted a clip he took of the river with his drone to Instagram.

A short clip with some of the footage I got of the #orangeriver here in #durangocolorado #colorado #drone #dji #phantom #video A video posted by Ian Lee (@lli_photography) on Aug 6, 2015 at 9:28pm PDT

According to the EPA, the spill occurred when one of its teams was using heavy equipment to enter the Gold King Mine, a suspended mine near Durango. Instead of entering the mine and beginning the process of pumping and treating the contaminated water inside as planned, the team accidentally caused it to flow into the nearby Animas River. Before the spill, water carrying "metals pollution" was flowing into a holding area outside the mine.

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