A river reborn.
For more than a century, central Colorado's upper Arkansas River was afflicted with a near-terminal case of metal-mine-drainage pollution (see "Yesterday's Mines Poison Today's Rivers," American Forests, February 1984). But after a decade of work, an expenditure of $40 million, and an ongoing controversy over cleanup costs, this jewel of a mountain river has a new lease on life.
When I first saw the upper Arkansas near Leadville, Colorado, in 1970, it was already long dead. The effects of a century and a quarter of mining continued to reduce parts of the river to a sewer of toxic waste, devoid of fish and lined by stained, barren banks. Even in recent years, I witnessed occasional uncontrolled surges from an old mine-drainage tunnel that released a torrent of toxic, yellow-brown waste and discolored the Arkansas for 60 miles downstream.
Thanks to a massive, decade-long cleanup effort, the surges have finally ended, the toxic flow of mine drainage has been largely stemmed, and brown trout will soon return to the river. I'll be fortunate enough to experience something not even Leadville's old-timers' fathers could remember: a clean, healthy upper Arkansas River.
Questions about the cost-effectiveness of the solution and liability for the damage will linger for years. Nevertheless, the work established legal and technical precedents for cleaning up other metal-mine-drainage problems across the West.
River cleanup is often equated simply with improved water quality, but it also benefits everything from fisheries, recreation, and aesthetics to soil quality, vegetative restoration, and rehabilitation of riparian habitat.
Metal-mine drainage adversely affects more than 4,500 miles of western streams and rivers. Mine-drainage water--characterized by excessive levels of acidity and heavy metals--is created by the oxidation of metal sulfide minerals. The primary culprit is pyrite, or iron disulfide, an abundant mineral associated with most precious and base metal ore deposits.
When exposed to atmosphere and water, pyrite reacts with oxygen to form sulfuric acid, which, in turn, liberates iron ions. When the acidic, iron-rich drainage flows into normal streams, dilution raises its pH. This decrease in drainage acidity renders the iron ions insoluble, causing them to precipitate, or separate from solution, in the form of brightly colored iron hydroxide, called "yellow boy." Large quantities of iron hydroxide can clog stream beds and discolor rocks and banks a telltale rusty orange. Mine-drainage water often carries excessive loads of other dissolved heavy metals such as zinc, lead, silver, copper, and cadmium; in sufficient concentrations, these are toxic to various forms of aquatic life.
The upper Arkansas, a classic example of mine-drainage pollution, is pristine until it passes Leadville, once one of the nation's greatest metal-mining districts. By 1900, Leadville's 400 individual mines had yielded $200 million in gold, silver, lead, zinc, and copper. More than 100 miles of underground workings and enormous heaps of pyrite-rich mine and mill wastes generated an endless stream of mine-drainage water.
Leadville miners completed the Yak Tunnel, a major mine-dewatering project, in 1906. The Yak, a four-mile-long combination ore-haulage and drainage tunnel, drained 60 miles of underground workings within a 16-square-mile area. The acidic, heavy-metal-laden drainage water flowed into California Gulch, then into the Arkansas River. Such "free" disposal of mine-drainage water was legal and in full accordance with then-prevailing concepts of land and water use.
During World War II, the War Production Board ordered many Leadville mines to speed up to emergency production levels. To dewater more mines and boost output, the U.S. Bureau of Mines in 1943 used federal dollars to construct the Leadville Mine Drainage Tunnel. During the Korean War, the Bureau of Mines completed the two-mile-long Leadville Drain, which released acidic, metal-rich effluent directly into the East Branch of the Arkansas River. In 1959, the Bureau of Reclamation acquired the Drain as a 3.5-million-gallon-per-day supplementary source of general-use water for diversion projects.
Most Leadville mines closed by the 1960s, but the tunnel drainage continued--a total of four million gallons a day, containing about one ton of dissolved metals. At Leadville, the effect on the Arkansas was devastating. The upstream fish count--3,200 per mile--dropped abruptly to zero; for several miles downstream, the Arkansas remained biologically dead. The mine drainage lowered fish population counts, curtailed longevity, caused erratic growth, and elevated metal levels in the flesh of fish as far as 40 miles downstream.
Views on mine drainage, and on the environment in general, changed radically in the early 1970s with passage of the Clean Air and Clean Water Acts and creation of the Environmental Protection Agency. Leadville's mine drainage was formally classified as "pollution," and extensive federal and state field testing determined that more than 90 percent of the effluent impacting the upper Arkansas originated at the two old drainage tunnels.
Attention focused first on the federally constructed and owned Leadville Drain. In accordance with new guidelines, the Bureau of Reclamation was issued the required discharge permit limiting effluent pollutant levels. Since those limitations were grossly exceeded, EPA formally ordered the Bureau of Reclamation to comply.
Work on the partially caved-in Drain began in 1980 with structural rehabilitation. Miners used concrete forms to shore up and stabilize one mile of the crumbling tunnel, eliminating the possibility of future cave-ins that might block and "back up" the flow. When the EPA approved a cleanup plan in 1988, the Bureau of Reclamation began constructing a small $250,000 pilot plant to prove the basic design of a permanent plant that would be capable of treating the entire tunnel drainage.
Work at Leadville progressed smoothly as a public-works project under Clean Water Act guidelines. But cleanup was far more complex and controversial at the privately owned Yak Tunnel and California Gulch, where hundreds of individually owned mine properties contributed to the drainage.
In 1983, California Gulch was among the first metal-mine-drainage sites named to the EPA's national Superfund priority cleanup list. The EPA, with few precedents to follow, moved to identify "responsible parties" to share in cleanup costs, under authority of the Comprehensive Environmental Response Compensation Liability Act (CERCLA).
Attention focused on Resurrection-Asarco Joint Venture, owner of the Black Cloud Mine, the last continuously active Leadville mine. Formed in 1955, Joint Venture held historic mining properties that contributed to the Yak Tunnel drainage. Even though modern operations complied fully with Clean Water Act regulations, Joint Venture was identified as the primary "potentially responsible party" (PRP).
Most Leadville residents questioned the fairness of holding Resurrection-Asarco Joint Venture--along with other minor PRPs, including mortgage companies and individuals--liable for environmental damage caused by early mining. Others feared that any resulting financial burden might jeopardize remaining mining jobs and ruin any chance for a revival of local mining. Merchants believed the Superfund designation would damage Leadville's developing tourism industry.
Turmoil within the EPA and a battle with the Colorado Department of Health over administrative control added to the problems. Nevertheless, despite time-consuming and costly litigation, alternative cleanup plans were developed and evaluated. The final plan, announced in 1989, called for partially plugging the Yak Tunnel to prevent "surges" and regulate flow, and constructing a large water-treatment plant. Under EPA order, all project design and construction costs were borne by Resurrection-Asarco Joint Venture.
Both the Leadville Drain and the Yak Tunnel-California Gulch water-treatment plants went on line in 1992. The Bureau of Reclamation spent $5 million to build the Leadville Drain plant in accordance with Clean Water Act requirements. The plant costs $600,000 annually to operate and treats an average tunnel flow of 1,500 gallons per minute. The recovered heavy-metal sludge is disposed of in approved landfills, and water released into the East Branch of the Arkansas now meets chemical standards for drinking water.
The California Gulch plant, which serves the same basic purpose but was built to comply with far more stringent Superfund requirements, cost $8.5 million. The plant treats an average of 350 gallons per minute, and the released water meets chemical standards for drinking water. The in-perpetuity operating cost, about $1 million per year, is also borne by Resurrection-Asarco Joint Venture.
Recovered metal-oxide sludge from California Gulch is mixed with local mill ore concentrates and shipped to an out-of-state smelter for metal recovery. Although the metals won't begin to cover operating costs, the principle of "environmental cleanup resource recovery" could play a big role in future environmental-cleanup planning.
Superfund controversies remain, but most of the 50,000 residents in three counties along a 70-mile stretch of the upper Arkansas River agree that the cleanup will provide long-term environmental and economic benefits. "We have great lakes here," comments Mike Cerise, a sporting-goods dealer and avid fisherman. "Now we'll have a great brown-trout river, too. That will attract fishermen and boost our image in tourism and outdoor recreation. But I don't think that making today's mining companies pay for something that happened a hundred years ago was fair."
Jim Hanley, EPA remedial project manager for the California Gulch Superfund site, believes that without Superfund action, the Arkansas would still be heavily polluted. "California Gulch has been a learning experience for everyone involved," Hanley concedes. "And the biggest lesson may be that Superfund is not necessarily the best way to tackle mine-drainage pollution. Cleanup goals might be met in a less rigid manner, possibly by granting the states more authority, and certainly by granting private industry, if it is to be held liable for cleanup, the flexibility and control to allow for more cost-effective cleanup."
The clear winner in all this has been the river itself. And the benefits of eliminating more than 90 percent of the metal-mine-drainage pollution extend far beyond improved fisheries, more appealing water recreation, and river aesthetics.
"The Arkansas cleanup will show the basic interrelationships and instructiveness of our environment," says Mac Berta, area manager of the U.S. Bureau of Land Management's Royal Gorge Resource Area. "Improved water quality is going to positively affect riparian habitat all along the upper Arkansas.
"We know that mine-drainage pollution adversely affected the entire aquatic food chain because of high metal levels in tissues. Although much more botanical study must be done, it seems certain that plant life is also adversely affected. Many of the original riparian vegetation that was not tolerant to the pollution are doing poorly or have disappeared entirely. In the long term, I believe elimination of the mine-drainage pollution . . . may permit a return of many historic natural species."
Though the river cleanup has been costly and controversial, it shows that more than a century of mine-drainage pollution can be overcome. And it bodes well for future efforts of this type.
"No matter how we go about it, environmental cleanup isn't going to be cheap," notes Colorado Division of Wildlife biologist John Woodling, who has spent years studying the upper Arkansas. "But there really isn't a choice. We can make a lot of things today, but rivers aren't one of them. So we're all going to have to begin taking better care of what we have. That's what is happening here. We're bringing back a river."
EPA DRAINAGE CLEANUP SITES
Across the West, mine-related pollution problems include not only acid-heavy metal-mine drainage but also cyanide and radioactive uranium wastes as well. The EPA is already involved in cleanup operations, similar to the one on the Arkansas, at 13 other pollution sites involving mining, milling, or smelting operations that adversely affect both groundwater and several hundred miles of western rivers.
Along with Leadville's California Gulch, other Colorado sites include Smuggler Mountain at Aspen, Clear Creek at Central City, the Eagle Mine at Gilman, the Lincoln Park uranium mill site near Canon City, uranium mill sites at Uravan, and a cyanide-leach open-pit gold mine at Summitville.
Cleanup is also underway at the Silver Mountain Mine near Tonasket, Washington; the Bunker Hill mine/mill-smelter complex near Kellogg, Idaho; smelter sites at East Helena, Montana; four sites in the Silver Bow Creek-Butte area of Montana; and a Midvale, Utah, steel-smelter site. The EPA is also investigating other mining-related pollution sites for possible future remedial action.
Stephen Voynick has authored mining-related books and wrote an American Forests feature about the Arkansas before the cleanup.
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|Title Annotation:||includes related article; Arkansas River|
|Author:||Voynick, Stephen M.|
|Date:||Sep 1, 1993|
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