Colorado’s Abandoned Mines Need Regulatory Reform

Note: This is a modified excerpt from my forthcoming book, Where Land Becomes Sky: Life and Death Along the Colorado Trail, available for preorder now.

Climb toward the heights of Colorado’s Kokomo Pass, some 20 miles northeast of Leadville and 12,000 feet above the sea, and you’ll be treated to spectacular views. The Sawatch Mountains sail in the distance, snow-capped and picturesque. The Collegiate Peaks rise beyond the depths of the Arkansas River Valley, and to the south, the Sangre de Cristos undulate and fade to faint blue hues in the distant sky. Nearer slopes are smothered by tundra and thickets of lodgepole pine, Engelmann spruce and subalpine fir. Meadows are abloom with wildflowers — mountain bluebells, alpine daisies, blue columbines, golden asters and arctic gentians, among others. The landscape is stunningly beautiful and seemingly pristine.

And if you were to trek just south of Kokomo Pass’ apex, and you stopped and gazed still further south, you’d see a landscape that is anything but pristine. You’d see a reservoir half full of copper-orange sludge, stained with the runoff of acid mine drainage. Other reservoirs of dark and murky water dot the floors of nearby valleys and gulches. Rust-colored mine tailings blemish crumbling slopes surrounding pits of darkened runoff. More distant mountains, too, bear rust-colored hues, where entire mountain sides have been turned inside out, quarried into steppe-like formations; devoid of vegetation. Across the valley, straddling the Continental Divide along Fremont Pass is the Climax Mine, where a large, orb-like structure resembling the Death Star sits at the center of the largest molybdenum mine in the world. From 1925 through the 1970s, more than half of the world’s molybdenum (a metal used in the production of steel and other strong, sturdy alloys) was mined from these mountains. Surrounding slopes are timbered by pine, but vast expanses of the landscape are lifeless in appearance, scarred by mining operations beginning in the late 1800s.

Behold: The Leadville Mining District, home to some of the richest lead, zinc and silver deposits in all the world.

The bulk of Colorado’s mountain towns were settled by frontier folk in pursuit of a fortune, Leadville among them. It all began with the discovery of gold along the banks of the South Platte River, near Denver, during the year of 1850. Then, larger, more promising deposits were unearthed, and the Pike’s Peak Gold Rush was on. By 1860, more than one hundred thousand miners and prospectors had crawled across the Great Plains, bound for the mountains of Colorado. From a bird’s eye view, they must have looked something like ants on a pheromone trail. The settlers came in search of gold, silver and other precious metals. They constructed tens of thousands of mines across Colorado, probing the state’s mountain ranges for gold and silver, iron and copper, lead and molybdenum, among other metals and minerals. A select few of these mines proved successful, their prospectors striking it rich and going on to establish nearby towns — like Leadville, for example, home to the National Mining Hall of Fame and Museum.

Mining boomed for decades in the state of Colorado. By the late 1800s, however, the prices of gold and silver had plummeted. The minerals were being phased out as currency, and the stuff was becoming harder to mine as easily accessible deposits of ore were depleted. All the low hangin’ fruit had been plucked, and many mines could no longer turn a profit. With time, Colorado’s historic mining operations were abandoned.

A century on, and scientists from the Colorado Geological Survey (CGS) set out to see just how many neglected mines populate the state’s mountains. Throughout the 1990s, officials with the CGS identified 18,382 abandoned mine sites scattered across Colorado’s Rockies. And hundreds of these abandoned mines, they discovered, had been leaching acid mine drainage and heavy metals into the headwaters of the state’s major river systems for the better part of a century. The Arkansas, Las Animas, Rio Grande, Alamosa, and Uncompahgre Rivers; all were polluted — and were continuing to be polluted — with acid mine drainage flowing from the state’s forlorn mine sites. By the numbers, 672 of Colorado’s abandoned mines were found to pose “potentially significant hazards” to local watersheds, in the words of the Survey. Upwards of 200 abandoned mines had caused the “significant degradation” of local ecosystems, and 26 had caused “extreme degradation.”

When mining operations upturn the Earth, minerals like pyrite (otherwise known as iron sulfide, or “fool’s gold”) — a common mineral ore in the Rocky Mountains — are exposed to the atmosphere. This process happens naturally, of course, at the slow, steady pace of erosion. But mining accelerates the process drastically. When water and oxygen encounter pyrite, a chemical reaction occurs, generating a solution of sulfuric acid and dissolved iron. Other metals like copper, lead and mercury dissolve in the runoff, as well. The end result is known as acid mine drainage — a concoction of highly acidic water and exorbitantly high quantities of heavy metals.

And when rainfall and snowmelt flow into the thousands of abandoned mine shafts Swiss-cheesed throughout the mountains of Colorado, the water tends to form acid mine drainage en masse (or, rather, en gros volumes — “in large volumes”). As acid mine drainage accumulates in abandoned mine shafts, the solution tends to leak and flow through the old, porous, haphazardly constructed forms. Some shafts collapse entirely. And with time and erosion, the resultant acid mine drainage flows still further on into rivers, streams, lakes and groundwater downslope, where the health of fish and other aquatic organisms — along with human drinking water — are threatened.

California Gulch, for example, the site of the Leadville Mining District, is home to 75 mills and 44 smelters held over from the region’s ole’ mining days. More than two thousand waste rock piles blanket some 600 acres across the gulch, where the blowouts of mine drainage tunnels, combined with seasonal spring runoff, have carried approximately 115,000 cubic yards of fluvial tailings to the floodplain of the Arkansas River. Today, as a result of this historic pollution, the floodplain of the Arkansas “seasonally exceeds state aquatic life standards for several metals including zinc, lead, cadmium, and copper,” in the words of the United States Fish and Wildlife Service.

Peru Creek, as another example, which flows downstream from the Pennsylvania Mine in the mountains northeast of Breckenridge, has been rendered functionally extinct — devoid of fish and other marine life — in the wake of more than a century of acid mine drainage polluting the waterway. The same can be said of several creeks and streams across Colorado and the greater American West. Hundreds of defunct gold, copper and silver mines bestrew the mountains surrounding Helena, Montana, for instance, the pollution from which renders the “drinking water” of hundreds of residents undrinkable. And the 500,000 abandoned mine sites scattered about the United States pose similar threats to drinking water supplies across a considerable fraction of the country. According to the Environmental Mining Council of British Columbia, acid mine drainage flowing from the United States’ abandoned mines has, to date, contaminated more than 135,000 acre feet of reservoirs and 9,000 miles of the nation’s rivers and streams. Meanwhile, more than 40 percent of Western watersheds have been (and are being) polluted by historic mining operations, according to the Environmental Protection Agency.

Issues of abandoned mines and acid mine drainage pollution have been known to science for decades. Yet, no clear solution seems to be in sight. More recent studies have only further illustrated the scale and severity of the problem, in fact. “Most recent data reports there are over 23,000 abandoned mines across the state and 1,800 miles of streams impaired due to acid mine drainage related pollutants,” a 2017 joint report from the Colorado Department of Public Health & Environment and the Colorado Department of Natural Resources Division of Reclamation states. And of the tens of thousands of historic mines strewn about the state of Colorado, few have been so much as assessed for effects on water quality and ecological health.

Even fewer abandoned mines — in Colorado and elsewhere — have attracted the attention of the Environmental Protection Agency. Historically, Colorado has been home to hundreds of Superfund sites — locations so thoroughly polluted that the EPA, among other federal agencies, deem it necessary to step in and clean up the mess. Many such sites were abandoned mining operations. At present, the EPA acknowledges 25 National Priorities List (NPL) sites in the state of Colorado; which are, in effect, Superfund sites in need of further assessment and cleanup. And ten of these sites (otherwise known as Comprehensive Environmental Response, Compensation, and Liability Act, or CERCLA, sites) were directly polluted by historic mining operations.

The Gold King Mine is perhaps the most well known. Located near the town of Silverton, established in 1887 and abandoned in 1923, the EPA began cleanup operations at the site in 2006. In 2015, while EPA restoration crews worked in attempts to fortify and seal the abandoned mine shafts, the weakening, rotting structures held over from the mine’s operating days collapsed. An estimated three million gallons of toxic, heavy-metal laden sludge flowed into the Animas River, and flowed further on into the San Juan. For days, waterways ran orange, from Colorado down to New Mexico and on over to Utah. The pollution flowed as far as Lake Powell, where the San Juan confluences with the Colorado River. In the wake of the Gold King blowout, the EPA constructed a $1.5 million water treatment plant to rid the Animas of acid mine drainage-related pollutants. The plant costs upwards of $3 million per year to operate. And still, water quality downstream of the Gold King Mine remains an ongoing concern among those living along the Animas River — the River of Souls.

Leadville’s California Gulch is yet another one of Colorado’s Superfund Sites — a site where historic mining operations contaminated more than 18 square miles of soil, surface water, and groundwater, including those in and around the town of Leadville itself. Thousands of piles of heavy metal-rich mine tailings once layered the floor of California Gulch. Some still do. In the mountains above town, tunnels were carved into mountain sides like the boring holes of bark beetles, and the discharge of dozens of mines was channeled down into California Gulch and its resident ravine, which flows further on, straight through the town of Leadville. California Gulch was assigned Superfund status back in 1983, and to date, the EPA has removed “350,000 cubic yards of contaminated soils, sediments and mine-processing wastes.” And still, cleanup operations remain ongoing in the Leadville Mining District.

The point is, even among sites warranting the funding and attention of the Environmental Protection Agency, the problems posed by historic mining operations often prove complex and difficult to solve.

But the vast majority of Colorado’s 23,000-plus abandoned mine sites and their discharge of acid mine drainage escape the scrutiny of the EPA. Officials have yet to perform even basic risk assessment analyses on an estimated 80 percent of historic mines populating the nation’s public lands. And among the mines that have been studied, cleanup actions have yet to be initiated in locales failing to meet Superfund criteria. And here’s the thing: the fact that an abandoned mine site isn’t assigned Superfund status doesn’t mean that such a site poses no threat to the environment. In Colorado’s San Juan Mountains alone, upwards of 400 neglected mines have been leaking a combined 15 million gallons of acid mine drainage into the San Juan and Animas watersheds per day, every day, for more than a century. And still, nothing is being done to stop them.

I’m reminded of that Rumsfeld line: “There are known knowns. There are things we know we know. We also know there are known unknowns. That is to say, we know there are some things we do not know. But there are also unknown unknowns, the ones we don’t know we don’t know.” Colorado’s problem with abandoned mines, and the severity of the ecological consequences posed by these forlorn mine sites, are a known unknown. We know that these mines are a problem, and we know that the full scope of the problem remains unknown to science.

Most of Colorado’s historic mine sites were established in accordance with the General Mining Act of 1872 — a long-standing federal law authorizing and governing prospecting and mining claims on America’s public lands. The act is riddled with loopholes, permitting lax environmental safety protocols and hazardous concentrations of acid mine drainage to be discharged into a given mine’s surroundings without recourse. Even America’s wildernesses aren’t immune to the sweeping implications of the General Mining Act. Since its enactment in 1964, the Wilderness Act has allowed historic mining claims to remain open in the wilderness areas of the United States, and until 1984, allowed new claims to be staked in the wilderness; “an area where the earth and its community of life are untrammeled by man, where man himself is a visitor who does not remain,” in the words of the federal government itself. And with respect to historic mines within the boundaries of America’s wilderness areas and greater public lands, the founders and operators of these mines — individuals and, in many cases, corporations alike — died and disbanded long ago. Thus, identifying who, exactly, should be held accountable for these forgotten mine sites and their ongoing pollution of Coloradan and American watersheds remains an open question.

“Because historic draining mines may continually discharge high concentrations of pollutants,” the 2017 Colorado Abandoned Mines Water Quality Study reads, “perpetual treatment or long-term remedies are required.” And such remedies cost a lot of money. “It is a long standing policy of the Water Quality Control Division to not pursue discharge permits for mining features that are inactive with undetermined ownership. There are also liability concerns over the treatment of discharge from abandoned mines.” Plainly, unless a site has already been assigned Superfund status, any agency or organization ambitious enough to so much as attempt to remedy the pollution flowing from a given mine site would, by laws specified in the General Mining Act of 1872, assume liability for reducing and maintaining pollution levels at that site to Clean Water Act standards, “for an indefinite period of time.” A costly, long-term project, to be sure.

It’d be an understatement to say that government agencies and environmental groups are financially disincentivized from cleaning up Colorado’s (as well as the nation’s) abandoned mine sites. But that is, in effect, what the issue boils down to. It’s a matter of incentives, on some level, and if taking on an issue means committing financial suicide, solutions to such issues are apt to remain illusive. Thus, until regulatory reform is enacted and legislation is passed that better incentivizes the cleaning up of Colorado’s abandoned mines, proper action effectively can’t be taken to remedy this issue, and untold volumes of acid mine drainage will continue to flow into Colorado’s watersheds for the foreseeable future — home to the headwaters of the country itself.

The full suite of downstream effects such pollution will have on the state’s flora, fauna, ecosystems and human drinking water supplies is another known unknown, so to speak. As are the particularities of the reform needed to solve these issues. I, for one, don’t know what such reform would look like. I’m not sure that anybody does. But the reform we need can only begin with an honest, unflinching acknowledgment of the problem at hand.

And of course, the problems posed by abandoned mines and acid mine drainage pollution aren’t unique to Colorado, though they are pronounced in the Centennial State. The regulatory reforms needed to resolve Colorado’s matter with abandoned mines must occur on the federal level, and the issue is nationwide. More than half a million abandoned hardrock mines litter Bureau of Land Management, National Park Service, and National Forest Service lands across the country, according to databases maintained by the Environmental Protection Agency. And with the current resources, staffing and funding allocated to this issue, the BLM estimates that it will take about 500 years to inventory all of these historic mine sites.

How long the cleaning up will take from there is anybody’s best guess; yet another known unknown.