MINTURN, Colorado — Crews on Wednesday continued their efforts to thaw a pipeline that transports water contaminated by zinc, cadmium and other heavy metals from the Eagle Mine to a water treatment plant.

The 10-inch pipeline, held aloft by trestle as it crosses Rex Flats and the Tigiwon Road, froze solid during December. Without that pipeline, there is some risk of water from the mine seeping out and into the Eagle River, similar to what happened in 1990, if at diminished concentrations.

To reduce the potential for such a spill, CBS, the company legally responsible for cleanup of pollution from the mine, has been hauling contaminated water from the mine by truck to the treatment plant.

State and county officials say they believe the trucking of water has substantially reduced the risk of a spill.

“The level of risk (of a spill into the Eagle River) is pretty low at this point,” said Wendy Naugle, project manager for the Colorado Department of Health and Environment.

Ray Merry, Eagle County's director of environmental health, similarly downplayed the risk, describing the potential for contamination of the river as “pretty remote.”

“Does this reverse the progress of the last 20 years? No. This is a bump in the road,” he said.

Even if polluted water from the mine began leaking out, he added, backup systems are in place to mitigate the risk. Moreover, water in the mine is cleaner.

Precautions taken

But Eagle River Water and Sanitation District, which delivers water to communities from Vail through Edwards, has taken precautions. First, it topped off all storage tanks, to better ensure sufficiency of supplies. As well, operators of treatment plants in Avon and Edwards have been taking the extra step of sampling water in Minturn before drawing water from their plants downvalley.

The district has also stopped pumping water from the treatment plant in Avon to Vail, which is common in winter, and is instead relying entirely on water from its wells near the Vail Golf Club. If those wells should have trouble meeting demand, water could be released from Black Lakes, located at Vail Pass.

“Yes, there are backup systems in place (at the mine), but we don't know if it will work, and we feel it's better to be prudent,” said Diane Johnson, spokeswoman for Eagle River Water and Sanitation.

The potential for damage also caused the Colorado Division of Wildlife on Monday to lower trout in cages into the river, to serve as sentinel fish. If the fish die, explained Bill Andree, an Eagle-based biologist with the agency, toxicology tests will be conducted to determine what killed them.

Fish can tolerate far less zinc than humans, and some species of fish are less tolerant than others.

Crews have been working since at least mid-December to thaw the existing 10-inch pipeline by flushing it at high pressure with hot, salty water. With temperatures nightly descending below zero, they have had only partial success so far.

To provide a second backup, trucks carrying pipeline have arrived. Officials have said they expect the new pipeline will be laid by next week.

‘This is unacceptable'

This potential for polluted water draining into the Eagle River comes after two spills in the last year, the most recent on Dec. 1. In both cases, say officials, drinking water supplies were not tainted, although the water district did take precautions in one case.

Minturn gets its drinking water from Cross Creek, upstream from the confluence with the Eagle, and hence is unaffected.

Impacts of that December spill to fish are uncertain. State wildlife officers found no dead or distressed fish, but the ice cover made that conclusion only tentative. They expect to have a better idea in April, when fisheries biologists conduct their annual population sampling of the river.

But some officials say a disturbing pattern has emerged.

“This is unacceptable. They have an obligation to keep their treatment process operating continuously. We do,” said the Water and Sanitation District's Johnson.

She reported that the district is drafting letters that will be sent to state and federal officials in hope that changes will be effected to eliminate potential for spills.

“The bottom line is that we want to get this taken care of,” she said.

A similar sentiment was expressed by Melissa Macdonald, executive director of the Eagle River Watershed Council.

“We would like to see the state and EPA look a lot more closely at what has been going on,” she said.

A flawed plan

Pollution from the mine and then the cleanup has been an ongoing story for the last 30 years. And some local officials, such as Macdonald, think that more work will be needed to further remove contaminants to allow a greater variety of fish to survive.

Mines on Battle Mountain began operation in the 1870s and 1880s. The Eagle Mine consolidated some of these operations, producing zinc, silver, lead and other metals until 1977. The last inhabitants of Gilman, a company settlement, left in 1985.

The mining companies that caused the pollution were absorbed by Gulf + Western, a media conglomerate that is now part of CBS.

Under the federal Superfund legislation, an agreement to clean up the mine tailings that had discolored the Eagle River and killed fish was struck by state negotiators with company representatives in 1988.

That plan was deeply flawed. Water from the sealed mine began seeping through fissures in the rock, causing contaminated water to flow into the river. By March 1990, the river looked like old antifreeze, an unseemly mixture of green and orange. Fish disappeared entirely on sections of the river, and were scant on other sections. Upwards of several hundred people turned out at meetings in Minturn to angrily demand changes.

At that point, the Environmental Protection Agency became directly involved, overseeing a cleanup that resulted in a small mountains of spent ore — as processed rock is called — being moved into a consolidated pile near Minturn Middle School and then capped.

Officials declared the cleanup substantially complete in 2003. The cost has been unofficially estimated at $70 million to $80 million.

But to prevent further pollution, such as occurred in 1990, water from the mine must be treated into the forseeable future. Operation of such plants typically cost $1 million a year.

Changes sought

The Eagle River downstream from the river now supports brown trout, although levels of zinc — some from non-mine sources — remain too high for rainbow trout or the even more sensitive sculpin.

Ironically, while the water from the mine has had lower concentrations of heavy metals through the years, it has become more difficult to treat. Indirectly, that's what caused the current problem. Shipment of water into the plant was reduced to 17 gallons a minute down while the equipment at the plant was evaluated.

In past years, 17 gallons a minute was enough to prevent the pipe from freezing solid. This year, for reasons unknown, it was not.

The pipe collects water from two places: at Belden, the railroad siding deep in the canyon; and from Rock Creek, which is the small valley to the north of Gilman.

The danger has to do with whether the water in the lower levels of the mine reaches to the level that it begins seeping through fractures in the rock, emerging primarily in Rock Creek. That's what happened in 1990.

Water in the mine has been rising at an estimated foot a day, said Mike Holmes, project manager for the federal government's Environmental Protection Agency. But even should the tainted water emerge, it would be awhile before it caused levels of metals in the Eagle River to impact drinking water supplies, he said.

But even if no pollution results this time, officials say they want changes.

“The spill on Dec. 1 was due to an operator error,” said Holmes. “We're working through these things so they don't occur again,” said Holmes.

Local officials, meanwhile, say they also want improved communication from state and federal officials. Communication, said Jim White, the Minturn town manger, “wasn't very effective.” Merry, from Eagle County, and Johnson, from the Water and Sanitation District, had similar complaints.

As well, local officials believe that the treatment plant for the mine relies too much on automation.

Taking a longer view, local officials hope to push state and federal representatives to enter into new negotiations with CBS to embark on new efforts to further reduce levels of zinc in the Eagle River. The river has improved, said the Watershed Council's Macdonald, but it's still not the river it could, and should, be.

CBS, asked for comment Monday evening, had no comment by Tuesday night.