An EPA-supervised crew working inside the abandoned Gold King Mine in Colorado accidentally breached a wall holding back wastewater containing heavy metals, such as arsenic and lead.
The breach resulted in three million gallons of yellow/orange-colored waste spilling into the Animas River, which supplies drinking water to residents of Durango, Colorado (population 17,000). The river also flows through or near communities in New Mexico (Farmington, Aztec and Kirtland) and Utah’s Bluff, which is popular with tourists.
EPA initially said one-million gallons of contaminated water had flowed into the river before revising its estimates. The rate of the leak out of the mine was calculated at 1,200 gallons per minute.
EPA toxicologist Deborah McKean told reporters the “risk associated with exposure to a chemical is a matter of how much of the chemical you are exposed to.” Testing of water collected at sample stations along the Animas showed increased levels of arsenic, lead, aluminum, copper and other potentially toxic heavy metals, officials reported. “Those numbers are high and they are scary because they seem so high,” said McKean.
Discolored water had traveled 100 miles from where it originated within days, reaching municipalities in New Mexico. Two Colorado counties declared states of emergency. Durango city officials said an intake valve had been turned off prior to the spill. Durango Mayor Dean Brookie told the town’s citizens. “Your water never has been and never will be contaminated. Your water is safe to drink.”