This map shows polluted water discharge flow from 43 U.S. mining sites and levels of treatment of polluted discharge. Red locations indicate discharge for sites with zero treatment or storage of contaminated water. Graphic: Phil Holm / AP Graphic
This map shows polluted water discharge flow from 43 U.S. mining sites and levels of treatment of polluted discharge. Red locations indicate discharge for sites with zero treatment or storage of contaminated water. Graphic: Phil Holm / AP Graphic

By Matthew Brown
20 February 2019

RIMINI, Montana (AP) – Every day many millions of gallons of water loaded with arsenic, lead and other toxic metals flow from some of the most contaminated mining sites in the U.S. and into surrounding streams and ponds without being treated, The Associated Press has found.

That torrent is poisoning aquatic life and tainting water supplies in Montana, California, Colorado, Oklahoma and at least five other states.

The pollution is a legacy of how the mining industry was allowed to operate in the U.S. for more than a century. Companies that built mines for silver, lead, gold and other “hardrock” minerals could move on once they were no longer profitable, leaving behind tainted water that still leaks out of the mines or is cleaned up at taxpayer expense.

Using data from public records requests and independent researchers, the AP examined 43 mining sites under federal oversight, some containing dozens or even hundreds of individual mines.

The records show that at average flows, more than 50 million gallons (189 million liters) of contaminated wastewater streams daily from the sites. In many cases, it runs untreated into nearby groundwater, rivers and ponds — a roughly 20-million-gallon (76-million-liter) daily dose of pollution that could fill more than 2,000 tanker trucks.

The remainder of the waste is captured or treated in a costly effort that will need to carry on indefinitely, for perhaps thousands of years, often with little hope for reimbursement.

The volumes vastly exceed the release from Colorado’s Gold King Mine disaster in 2015, when a U.S. Environmental Protection Agency cleanup crew inadvertently triggered the release of 3 million gallons (11.4 million liters) of mustard-colored mine sludge, fouling rivers in three states.

At many mines, the pollution has continued decades after their enlistment in the federal Superfund cleanup program for the nation’s most hazardous sites, which faces sharp cuts under President Donald Trump.

Federal officials have raised fears that at least six of the sites examined by AP could have blowouts like the one at Gold King. [more]

50M gallons of polluted water pours daily from US mine sites