The Animas River turned a sickly orange-brown as waste from an abandoned mine near Silverton, Colorado flowed into the river. The water with high level of heavy metals has made its way down the river into New Mexico.
The cause? A breach from a team working for the Environmental Protection Agency that was trying to treat some of the contaminants in the mine. Here are a few things you should know about the spill as well as some other background.
The spill is now three times the original estimate
The EPA originally estimated that the spill was one million gallons of contaminated water. This weekend, the EPA revised the estimation and now says the spill was closer to 3 million gallons.
Contaminated water is still leaking from the abandoned mine. From the Farmington Daily-Times:
The mine continues to discharge 500 gallons per minute, EPA Region 8 administrator Shaun McGrath said in a teleconference call Sunday afternoon, but the polluted water is being contained and treated in four ponds at the site of the spill near Silverton, Colo.
After the plume passes, the river appears to be moving closer to normal.
The #AnimasRiver today at noon, 3.5 days after contamination reached Durango. Clearing up but cloudier than norm. pic.twitter.com/jRAQpJCYTd
— Kim Hannula (@stressrelated) August 10, 2015
So how much IS 3 million gallons?
Intel at last count used roughly 2.5 million gallons a day at the Rio Rancho plant, down from 4M as late as 2012;
— David Nelson (@DavidNelsonNM) August 10, 2015
A golf course uses about 270,000 gallons a day according to golf documents, so 3 million gallons is about 11 golf courses’ daily use; — David Nelson (@DavidNelsonNM) August 10, 2015
ABQ residents use roughly 75 million gallons of water a day, based on ABQWUA info.
— David Nelson (@DavidNelsonNM) August 10, 2015
Assuming 75 golf courses in the Denver area, daily use by them is roughly 20 million gallons. — David Nelson (@DavidNelsonNM) August 10, 2015
(To blow your mind on a Monday, ABQ residents use about 32 billion gallons of water a year.)
— David Nelson (@DavidNelsonNM) August 10, 2015
So not to minimize the Gold King mine disaster in any way, or go all @jfleck on everyone, but hopefully that helps visualize the amount. — David Nelson (@DavidNelsonNM) August 10, 2015
3 million gallons equal to all the water in the rec center (441,260 gallons) times seven: http://t.co/GgLGEVwGUZ pic.twitter.com/HeNTb2jxFW
— Shane Benjamin (@Shane_Benjamin) August 10, 2015
Why is it so toxic?

Photo Gold King Mine. Photo by EPA.
Chemical reactions.
OK, a better explanation:
For most of the West’s history, miners were basically allowed to run willy-nilly across the landscape, burrowing for gold, silver, or other valuable minerals. According to Ronald Cohen, an environmental engineer at the Colorado School of Mines, whenever you dig into a mountain, “at some point you are going to hit water.”
That water, when it runs through the rocks in a mine, hits a mineral called pyrite, or iron sulfide. It reacts with air and pyrite to form sulfuric acid and dissolved iron. That acid then continues through the mine, dissolving other heavy metals, like copper and lead. Eventually, you end up with water that’s got high levels of a lot of undesirable materials in it.
And that’s why there are now elevated levels of heavy metals in the river.
Abandoned mines are common
Until 1981, when a mine shut down for whatever reason, the owners could just essentially board them up and walk away. There was no requirement for rehabilitation plans or any plans to deal with the toxic materials left behind.
From Reveal, part of the Center for Investigative Reporting:
By some estimates, there are as many as half a million abandoned mines in the U.S. These sites have the potential to contaminate water, pollute soil, kill wildlife and sicken humans, to say nothing of the risks of falling down a hidden mine shaft. (This is a legitimate concern in some areas – in California, the state employs teams that scour the state looking for abandoned mines and plugging them up. There was even a “Dirty Jobs” episode about these folks.)
Spills aren’t uncommon either
The striking visual of the orange water flowing downriver, along with the massive size and cause of the spill, has created massive national interest in this spill. Smaller spills are relatively common throughout the West, as the Associated Press noted.
The federal government says 40 percent of the headwaters of Western waterways have been contaminated from mine runoff.
And Wired notes the same thing.
The abandoned mines in the area have long been a problem, filling up with acidic wastewater that leaches heavy metals out of rock and leaks into the river—a slow-motion environmental debacle. And the EPA has been trying to designate the mines a Superfund site for years, only to come up against local resistance. The mines still aren’t on the Superfund list, but the EPA has been trying to them clean up anyway.
In fact, the mine where the pollutants filled the Animas was itself leaking. The personnel were looking at the mine because of the pollutants that were seeping into the surrounding areas.
“These are historic abandoned mines that have had acid drainage for decades. That is the very reason why we were up there,” EPA regional chief McGrath said. “We were trying to reach that drainage coming off the Gold King Mine. They were trying to put in a treatment system.”
States of Emergency
The spill of pollutants has prompted areas to declares states of emergency. On Sunday, La Plata County and the City of Durango, both in Colorado, declared a state of emergency.
San Juan County in New Mexico declared a state of emergency this weekend as well.
The Navajo Nation declared a state of emergency and has already announced intentions to sue the Environmental Protection Agency over the spill that has disrupted life in the Four Corners area.
The state of New Mexico also will file suit.
Gov. Susana Martinez was the latest to declare a state of emergency, doing so Monday afternoon.
And one bonus thing, from another mine spill from over three decades ago.
Church Rock uranium mine spill
The Animas River spill is massive, but the 3 million gallons pales in comparison to another spill that slammed the Navajo Nation, 36 years ago.
A spill of radioactive material from the Church Rock Uranium Mine in 1979 leaked 94 million gallons of radioactive waste into the Rio Puerco.
New Mexico In Depth wrote about the spill last year, shortly before the 35th anniversary of the spill.
The radioactive material was a mixture of water and mill tailings, leftovers that retained toxic contaminants from the mining process that converted mined uranium into yellow slurry, known as yellow cake. The tailings were “placed in unlined evaporation ponds at the mill site,” the report says, meaning the radioactive goop that washed into the Puerco River and flowed through communities downstream was a public health hazard.
In 2009, shortly after the 30th anniversary of the spill, the Navajo Times wrote about the disaster, noting the health effects that have continued to impact the area decades later.
The Navajo Times story says the radioactivity was so bad that those who stepped in the water had blisters and and burns on their feet.
Update: Added that New Mexico also declared a state of emergency.