ALMA — Ninety miles west of Denver, 347 gallons a minute of acidic heavy metals leak into a tributary of the South Platte River every day from the defunct London Mine. Not even the bugs that fish eat have survived in South Mosquito Creek west of Alma, let alone the trout local leaders hope to restore for the South Park recreational economy.
The London Mine is one of many that leach toxic materials into Denver's watershed. Municipal water treatment plants keep contaminants from flowing out taps in homes; ecosystems, however, continue to be poisoned.
For years, state agencies and contractors worked on a cleanup at the London Mine, including installation of a water treatment plant.
But the resurgent discharge into Denver's watershed shows how difficult cleanup of old mines can be.
"You're never going to walk away from these things," said Bruce Stover, director of Colorado's inactive mine reclamation program. "Things happen inside mines that are unpredictable. Wood can rot. There's rock stress. Old mines are constantly changing. Gravity rules.
"You cannot just cork these up so it all goes away. That's not going to happen."
In one case, state officials have known for 22 years about a mine leaking 150 gallons a minute of metals-laced waste into a stream west of Boulder.
On Tuesday, state lawmakers at a legislative committee hearing began investigating the broader problem. Colorado health and natural resources officials told them it is so complex that state agencies have yet to prepare a full inventory and assess which mines are most prone to the kind of blowout that occurred Aug. 5 at the Gold King Mine above Silverton.
Other mines in the metro Denver watershed where state records show continuing contamination of streams and rivers include:
• The Perigo Gold Mine near Nederland discharges toxic liquid at a rate of 174 gallons per minute into Gamble Gulch, which flows into South Boulder Creek above Gross Reservoir, according to a March 2015 assessment by the Colorado Division of Reclamation, Mining and Safety.
In 1993, the Colorado Geological Survey conducted a study of inactive mines on U.S. Forest Service land west of Boulder and ranked cleanup at the Perigo Mine the top environmental priority. In May, backed-up water behind a collapsed portal surged out, spewing several thousand gallons of carrot-orange acid metal-laced water. State records show another blowout in 2011.
• At the Waldorf Mine west of metro Denver, a blowout in 2013 triggered a cascade of hundreds of gallons of orange liquid waste into Clear Creek. State officials said elevated levels of zinc and lead have leaked from this mine for years, about 70 gallons per minute, and records show cleanup is not completed. A mine opening "continually drains and intermittently discharges large surges of contaminated water that erode the mine waste pile."
• At Geneva Mine above Georgetown, a "belch" in 2013 sent a surge of metals-laced drainage that turned Geneva Creek yellow.
• At the Puzzle Mine above Breckenridge, EPA and state officials have known since 2006 about draining water, at least 50 gallons a minute, laced with zinc and cadmium at levels several times higher than the state standard, records show. A few years ago, Breckenridge residents watched the Blue River turn orange after ice melted inside the mine and pooled contaminants gushed through town toward Dillon Reservoir.
Colorado mining officials "are just beginning to investigate" possible action to address the leaking Puzzle Mine, Stover said.
Congress is giving greater attention to the problem in the wake of the Gold King disaster, which unleashed a deluge of 3 million gallons of mustard-colored liquid into the Animas River.
Sen. Martin Heinrich, D-New Mexico, said he'll introduce legislation to reform the 1872 Mining Law and create a national cleanup fund drawn from industry royalties.
"If we don't create a reclamation program, then this situation is going to happen again and again," Heinrich said.
Colorado Sen. Michael Bennet has supported action to encourage cleanups by shielding companies and conservation groups from liability, but he has not committed to help create a national cleanup fund drawn from mining industry royalties. Heinrich said he'll press Bennet, D-Colo., and Republican Sen. Cory Gardner for support.
Bennet's staffers say the senator is supporting efforts to reform the mining law, including charging mining companies royalties to create a cleanup fund and he is "working with" Heinrich and New Mexico Sen. Tom Udall.
Environmental groups contend that, beyond liability reform, better funding is essential to deal with the West's estimated 500,000 inactive mines, which have tainted 40 percent of watersheds at a time when residents increasingly seek more water.
"The federal and state governments should wake up and fix the problem before more spills occur," said Alan Septoff of Earthworks, a Washington D.C.-based advocacy group. "This matters because the mines drain acid into water that we use for drinking and that drives economies, like the economy in La Plata County."
Colorado officials said they do as much as they can with limited legal power and resources.
"We know where the draining mines are, but a statewide prioritization has not been done. That's something we're talking about now," Stover said.
Nor does the state keep a list of mine site owners. Most owners are not "viable" as sources of funding for cleanups, state natural resources spokesman Todd Hartman said. Only the EPA can determine whether "potentially responsible parties" may exist and are viable, he said.
Meanwhile, three or four inactive mines blow out each year, spewing backed-up metals-laced waste into waterways. That's in addition to trickles and seeps from scores of inactive mines that, by state and federal estimates, inject the equivalent of a Gold King disaster every two days.
At the western edge of South Park, the London Mine mess shows how, even when state and federal agencies do embark on a cleanup, solutions are prone to coming undone.
The Colorado Department of Public Health and Environment on July 30 ordered an estate trust responsible for London Mine LLC to stop the toxic discharges, detailing cancer-causing cadmium at levels up to six times higher than the state health limit and zinc at three times the limit.
"It is loading the creek. That is our concern," said Pat Pfaltzgraff, director of CDPHE's water quality control division.
CDPHE is pursuing a $240,000 penalty against the estate of the now-deceased owner.
In the past two decades, state officials relied on EPA help to target London Mine LLC as a potentially responsible owner. The state in 1997 built a water treatment plant and settling ponds along South Mosquito Creek, systems that intermittently have removed contaminants from mine water before they reached the creek and the watershed.
Last summer, state crews finished consolidating 80,205 cubic yards of tailings. Colorado and EPA officials publicly hailed a successful reclamation of the mine, enlisting youth volunteers in June 2014 to plant 2,000 trees.
But the collapse of a tunnel and removal of a concrete wall — attorneys for London Mine LLC and a third party dispute what exactly happened and who is at fault — have led to the flow of cadmium, zinc, manganese and other contaminants into creeks, state records show.
"We're going to be dealing with this forever," said Bill Dvorak, public lands organizer for the National Wildlife Federation. Dvorak surveyed the London Mine area last week on an Eco-flight over Mosquito Creek.
Park County officials increasingly bristle at the seeming inability of state and federal authorities to compel a final fix at festering inactive mines.
"I've been hearing the same saga for a long time: 'How do you regulate an old mine? You have got to wait for the governor to call for designation as a superfund site,' " county administrator Tom Eisenman said.
This month, county commissioners are considering tougher county-level regulations that could help hold companies accountable for full restoration of land and water by collecting more bond money.
"We want another tool in our box," Eisenman said.
Locals say contaminants from the London Mine flow into the Middle Fork of the South Platte, threatening "gold medal" fisheries. They say they're also frustrated that a toxic spill in October from an active mine — the Alma Placer Mine — further degraded Mosquito Creek. Yet state mining regulators suspended much of fine they imposed on the owner — evidence some say of a lax approach.
"We should be considering what steps can be taken at the state level," said Sen. Ellen Roberts, head of the legislature's water resources committee and a resident of Durango, who stood on the yellow-caked banks of the Animas River after the Gold King blowout.
"We're going to have more of these spills around the state," Roberts said. "I've heard people talking about Gilpin County, Boulder County. It's a statewide issue. It is of a magnitude that all state legislators and the governor should be seeking a way to remediate the problems that are out there."
Bruce Finley: 303-954-1700, email@example.com or twitter.com/finleybruce