More than 3 million of gallons of wastewater from the Gold King Mine spilled into the nearby Animas River, turning it an alarming mustard hue.
The photos of the yellow-orange river were widely shared and have brought attention to a longstanding challenge that many were unaware of: how to regulate, treat and pay for the upkeep of abandoned and dormant mines in Colorado and across the country.
The Gold King Mine hasn't operated since 1923.
The EPA has been overseeing abandoned mine lands -- which can include bodies of water and surrounding watershed -- for many years. The mines can pose "serious threats to human health and the environment," the EPA says on its website, so the agency initiates and supervises the examination of these sites and tries to maintain or clean them up. The agency lists more than 15 case studies it has conducted of abandoned mines across the country, mostly in the West in states such as Colorado, Montana and California, but also in Vermont and Tennessee.
is a Washington-based nonprofit environmental group that works with communities near mines. The scientists and activists who work for the group have been concerned since the 1990s about contamination leaking from old, inactive or abandoned mines.
How dangerous could these mines be?
Those half a million mines, Earthworks says, have produced 50 billion tons of untreated, unreclaimed mining wastes on public and private land. The report notes that wastes can include arsenic, asbestos, cadmium, copper, cyanide, iron, lead, mercury and sulfur, among other material, and produce airborne pollutants.
In Colorado this week, leading toxicologists say there could be health effects for many years from heavy metals such as mercury and lead that spilled into the water of the Animas River. Exposure to high levels of these metals can cause many health problems, including cancer and kidney disease, and also lead to developmental problems in children.
"Oh my God! Look at the lead!" said Joseph Landolph, a toxicologist at the University of Southern California, after looking at the amount of lead in the Animas River, which was nearly 12,000 times higher than the acceptable level set by the EPA.
"This is a major, major problem," said Jonathan Freedman
, a toxicologist at the University of Louisville.
"Based on the data we have seen so far, (the EPA doesn't) anticipate adverse health effects from exposure to the metals detected in the river water samples from skin contact or incidental (unintentional) ingestion," the agency said. "Similarly, the risk of adverse effects to livestock that may have been exposed to metals detected in river water samples from ingestion or skin contact is low."
How did the leak happen and how did the EPA initially respond?
On August 5, Environmental Protection Agency workers were trying to place a pipe
into the opening of the mine to collect wastewater and prevent it from polluting Cement Creek and the Animas River. Before the spill, water carrying "metals pollution" was flowing into a holding area outside the mine.
Though it's unclear still exactly how the mistake was made, the EPA said the spill occurred when one of its teams was using heavy equipment to enter the mine near Durango, Colorado.
EPA Administrator Gina McCarthy apologized Tuesday for the spill and said, "I don't have a complete understanding of anything that went on in there. If there is something that went wrong, we want to make sure it never goes wrong again."
The amount of polluted water spilled was triple what the EPA originally estimated. The EPA first said 1 million gallons had rushed out. The U.S. Geological Survey then reported the size of the spill to be more than 3 million gallons. Blue water turned mustard-yellow and coursed into New Mexico within days. The EPA said this week it is helping provide water delivery to areas where water sources are contaminated.
How concerning was the Gold King Mine before the leak?
Earthworks' policy director Lauren Pagel
, who gave congressional testimony
about abandoned mines in 2013, told CNN that the Gold King Mine had been leaking acid mine drainage for years.
Acid drainage into water "often will make it too acidic for aquatic life to exist," she said.
But the Gold King Mine is not the only mine that is leaking.
Meeting minutes of the Animas River Stakeholders Group
show monthly discussions over wastewater leaks, pollution levels and efforts to address the problem.
The pollution from the mines has generally decreased since the 1990s and 2000s, according to reports, but has gotten worse in some areas.
How are locals reacting?
Several political leaders have expressed outrage at the EPA spill and declared states of emergency, but the Navajo Nation was the first to say
it would take legal action against the federal government.
"They are not going to get away with this," Navajo Nation President Russell Begaye said. "The EPA was right in the middle of the disaster, and we intend to make sure the Navajo Nation recovers every dollar it spends cleaning up this mess and every dollar it loses as a result of injuries to our precious Navajo natural resources."
Begaye also instructed the Navajo Nation Department of Justice to take action against the EPA.
In a release from the New Mexico Environment Department, state engineer Tom Blaine pulled no punches, saying, "Despite the fact that EPA did not notify New Mexico directly and took no action to alert New Mexicans to the potential danger, we took steps to ensure the protection of our water users in the area."
The attorneys general for Colorado, Utah and New Mexico said they might sue the federal government individually or collectively, though Colorado Attorney General Cynthia Coffman said, "It is too early to know if litigation is necessary or appropriate."
In a statement, the Utah attorney general's office said that all three states support an independent review of the mishap in addition to the EPA's review.
Can a state or individuals sue the EPA?
Citizens and others can sue any responsible party under the Clean Water Act citizen suit provision, said Pagel. The Clean Water Act and case law surrounding liability under that law is clear, but while the EPA team caused the disaster, the company that currently owns the mine site and any company associated with the pollution previously are also liable under the law, she said.
"It's sort of like suing yourself because any money the EPA pays out comes from us, the taxpayers," said Pagel.