Though the mining operations along a stretch of northwest Colorado were shut down decades ago, the lingering toxic pollution continues to plague state and federal officials who are grappling to protect two waterways and prevent continued fish stock declines and contamination of water for a burgeoning metropolitan area.
The long-abandoned Pennsylvania Mine continues to pollute Peru Creek with toxic metals, including lead and copper. The pollution in the creek has flowed miles downstream and contaminated sections of the Snake River, which winds for miles through the pristine White River National Forest and past first-rate ski lodges before emptying into a massive reservoir that provides drinking water for the Denver metropolitan area.
The mine pollution has decimated once thriving stocks of rainbow and brook trout, turning Peru Creek into the most polluted waterway in the Snake River watershed, said Jean Mackenzie, a remedial project manager at the U.S. EPA regional office in Denver who is overseeing the cleanup effort.
"There are no fish living in Peru Creek," Mackenzie said.
The polluted site has garnered national attention in recent years, due in part to efforts by local leaders and activists to use the EPA brownfields grant program to remediate Peru Creek. Though the brownfields program was originally designed to remediate old industrial pollution sites in urban areas, interest in applying the program more broadly has grown in recent years.
Environmental regulators are not sure how to clean up the mess, and they are also considering designating the area a Superfund hazardous waste site. Doing so would place a negative stigma on the area that could harm efforts to promote the region's recreational opportunities.
Either way, cleaning the site will be difficult.
A toxic legacy
The Pennsylvania Mine stands as just one example of the the toxic legacy left by thousands of abandoned mines that once formed the backbone of the economy in Colorado and other Western states in the 19th and early 20th centuries.
The federal Government Accountability Office estimates there are as many as 250,000 abandoned mines nationwide, the vast majority of which are in the western United States. The Mineral Policy Center calls these abandoned mines the greatest water quality threat in the region.
While the Western Governors' Association estimates that less than 20 percent pose an environmental problem, the U.S. Bureau of Mines has calculated that 12,000 miles of rivers in the western United States -- about 40 percent -- are contaminated with metals from mining operations. EPA projects it could cost as much as $50 billion to clean these rivers.
An estimated 15,000 deserted mines are on public lands managed by the Forest Service and the Bureau of Land Management. Congress allocates about $30 million annually to the two agencies to clean as many as 50 abandoned mine sites each year, according to federal records.
The Pennsylvania Mine began operation in the late 1800s. Like all hardrock mines of the time, it sought the gold and silver found in veins of metal sulfides buried underground. After the valuable metals were extracted, the leftover rocks were usually thrown into piles. The rain hitting the exposed rocks loaded with mineral sulfides allowed the metals to be released into streams, creeks and rivers, a process called acid rock drainage.
While the mine operation closed in 1940, it continued to pollute. By the late 1980s, the abandoned mine was discharging roughly 200 gallons per minute of "highly acidic water" into Peru Creek, according to studies, and the Colorado Division of Minerals and Geology started designing and constructing a treatment system for the Pennsylvania Mine.
But that project was abandoned in the early 1990s out of concerns about pollution liability and who would be required to maintain the cleanup for the decades it will take to complete.
Efforts to clean the site kicked back into high gear about eight years ago when local groups, state regulators and federal agencies including EPA and the Forest Service banded together to form the Snake River task force and find a solution.
Looking at a range of cleanup options
The question is how to achieve that cleanup.
About five years ago, Trout Unlimited proposed adopting a "Good Samaritan" cleanup in which it would raise the money and install a water treatment system in which they would construct a natural barrier, similar to a wetland, that would use microbes to consume the metals, thus filtering them out of the creek.
Meanwhile, the local community would apply for grants under the EPA brownfields program. But those plans were wiped out in the August 2007 rainstorm that washed huge volumes of metals into the creek and river, essentially killing all trout in both waterways for miles. The blowout demonstrated that more invasive treatment options must be employed, such as building a bulkhead near the outfall from the mine to control the volume of water that discharged into the creek. And that likely means an end to the "Good Samaritan" cleanup proposal.
"We realized that to design a system to account for something like that we'd have to have more money than we could ever raise," said Russell, the mine restoration project manager for Trout Unlimited.
The water treatment plant would have cost more than $1 million just to run electrical cables to the remote area, said Lane Wyatt, director of the water quality program for the Northwest Colorado Council of Governments.
And nobody wants electric transmission lines, roads and trucks cutting through the pristine area near the national forest. The ultimate goal is to design a passive treatment system in which pollutants are naturally filtered out of the creek over decades, said Elizabeth Russell, mine restoration project manager for Trout Unlimited in Boulder, Colo.
"To have some huge water treatment system out there would be ridiculous," Russell said.
Deadly impacts to fish
Local leaders believe that cleaning up the polluted mine site, and thus vastly improving water quality for miles downstream, would translate into an economic boon to the area.
In Colorado, where there are an estimated 20,000 abandoned mines, the widespread pollution has had a tremendous economic impact on local communities, said Timothy Brown, a historian at the University of Colorado at Boulder. Brown was one of the principal authors of a recent study detailing the effects of mining in the West that was conducted by the University of Colorado at Boulder and the Center of the American West.
"The streams in Colorado and across the West support fisheries that are very valuable to local communities," Brown said. "When you wipe out a fishery with acid mine drainage, it adds a real recreational loss to a community."
Local officials in Summit County, where the mine is located, say that by cleaning the creek and restoring trout to the Snake River they could better market the immediate area near the old mine as a fishing and recreational destination.
"Recreation is our bread and butter, the primary driver of our economy," said Brian Lorch, director of Summit County's Open Space and Trails Department.
The Keystone Ski Resort in the nearby town of Keystone stocks thousands of pounds of rainbow trout into the Snake River every summer for fishing. But the trout don't stay long; the fish leave -- or die -- because of the poor water quality created mostly by the abandoned mine, according to a study by Andrew Todd, a research biologist with the U.S. Geological Survey.
To determine the effects of the pollution on fish in the Snake River, Todd placed multiple cages, each containing 25 stocked rainbow trout, in three sections of the Snake River. The cage closest to the Pennsylvania Mine was about 4.5 miles from the site, and a second one was nearly 2 miles farther downstream.
Almost all the trout in the cage nearest the mine were dead within three days, according to the study published in July 2007 in a peer-reviewed journal. In addition, "significant mortality" of fish was observed at the second site downstream. None of the fish were dead at a third site on a fork of the Snake River that is not affected by the mine pollution.
When the gills of some of the trout nearest the mine site were analyzed, researchers found significantly high levels of lead and copper, according to the study.
"Over this short timeframe the water in the river was acutely toxic to these fish," Todd said in an interview. "Any reduction of metals loading in Peru Creek through a cleanup of the Pennsylvania Mine has the potential to get you closer to where you need to be for those communities of fish to survive year to year."
The search for solutions
The continued pollution and the anticipated expense to clean it up has led federal officials, and even some activists and local leaders, to concede that the area may need to be designated a federal Superfund hazardous waste site, which would require the Summit County Commission to formally request the governor to ask EPA to place the mine on the list of the country's most polluted sites.
Some locals are not thrilled with the idea. "There's some concerns about once things become Superfund, local and state control is really lost," said Wyatt, the Northwest Colorado Council of Governments official.
The negative stigma also concerns some at the U.S. Forest Service, which deals with the contamination to the Snake River portions running through the White River National Forest. "It would be nice to deal with the pollution without it having to be escalated to that level," said Jan Cutts, the Forest Service ranger for the Dillion District of the White River National Forest.
In addition, turning to the Superfund hazardous waste program to clean up the mess would come with a negative stigma, several interested parties noted. "When you're in a recreational economy, it certainly is a concern," Lorch commented.
Russell said a public meeting is scheduled for January to discuss the Superfund idea with local leaders and the community. She said Trout Unlimited would likely support designating the area as a Superfund site.
"In order to clean it up, I don't see any other way to make that happen," Russell said.
There remain, however, a number of potential alternatives to designating the area a Superfund site.
EPA is studying the flow of water from upstream areas that move through the abandoned mine and out into the creek.
EPA, working with the state of Colorado, is also studying whether it is feasible to close various portals inside the old mine to prevent flow into the creek, Mackenzie said. That project will be carried out this summer, she said.
One strategy that is almost certain to be employed is placing a bulkhead at the point where water flows out of the mine and into Peru Creek, Mackenzie and others say. The bulkhead would allow regulators to control the volume of water that comes out from the mine, which is particularly important during heavy rain events that can wash huge volumes of contaminated water into the creek.
"It's an amazingly complicated effort," Mackenzie said. "But if we could divert flow that would help the treatment system."
Trout Unlimited, the Northwest Colorado Council of Governments and another group have applied for a $200,000 grant to study the possibility of diverting the flow of water from Cinnamon Gulch upstream so that it does not come into contact with the contaminated rock. Another inexpensive cleanup measure involves removing tons of waste rock left by mine operators on the White River National Forest.
EPA will compile a list of alternatives, but that report will not be available until at least December 2009, Mackenzie said.
"It's slow going," Wyatt said. "But I think it would be a mistake to feel pressured to do something before you know what you need to do."
Scott Streater is a freelance journalist based in Colorado Springs, Colo.