Colo. Treatment Plant Improves French Creek and Blue River

After nearly a decade of effort and anticipation, the Wellington Oro water treatment plant turned on the pumps on Nov. 18. Officials from the town of Breckenridge, Summit County government, the U.S. Environmental Protection Agency, the Colorado Department of Public Health and Environment, and BioteQ Environmental Technologies dedicated the new water treatment plant to treat water discharging from the abandoned Wellington Oro silver-zinc mine site near Breckenridge, Colo.

The treatment plant is expected to remove cadmium and zinc from drainage entering French Creek at the mine site, resulting in improved water quality in the creek and an improved brown trout fishery in the Blue River. The design and construction of the plant was overseen by the federal and state environmental agencies.

"This is a decisive step in the effort to restore clean water to French Creek and the Blue River," said Bill Murray, director of EPA's Superfund Remedial Program in Denver. "This collaborative effort offers a precedent for overcoming obstacles to mine site cleanups, and today we celebrate an achievement that will improve habitat for fish and aquatic life for miles downstream."

The Wellington Oro site, once the largest mine in Summit County, is an abandoned silver and zinc mine three miles east of downtown Breckenridge in French Gulch. Although the mine ceased operating in 1972, water draining from more than 12 miles of tunnels, adits, and associated mine workings is contaminated with high levels of zinc and cadmium.

In 1989, EPA identified the Wellington Oro mine as a potential Superfund site. Since that time, the governing bodies and others have developed a plan to address the area's water quality problems while protecting alpine habitat and open space. This collaboration resulted in an alternative approach to Superfund, a first-of-its-kind settlement that has leveraged clean-up actions to improve water quality and has allowed the town of Breckenridge and Summit County to purchase and convert 1,800 acres of private mining claims known as the Golden Horseshoe into public open space, according to a press release.

The discharge from the Wellington Oro mine has been identified as the largest source of metals pollution in the Upper Blue River watershed. The treatment plant will remove more than 90 percent of cadmium and more than 99 percent of zinc from the mine drainage resulting in significantly lower concentrations of dissolved metals in the Blue River downstream of French Creek. Average cadmium and zinc concentrations at the untreated mine discharge are 59 µg/l (micrograms per liter) and 123,000 µg/l, respectively – concentrations that are much higher than brown trout can tolerate. The water discharged from the treatment plant will have a cadmium concentration of less than 4 µg/l and a zinc concentration of less than 225 µg/l.

Vancouver, B.C.-based BioteQ designed and engineered the new treatment plant. The BioteQ process for water treatment and metal recovery, which uses sulfide precipitation, was selected as the best technology to remove dissolved cadmium and zinc from mine drainage at the site. The process allows for the dissolved metals to be removed from the water in a form that can be sent to a refinery and recycled.

The town of Breckenridge Water Division will operate the plant, which is designed to treat a maximum of 150 gallons per minute and will operate 24 hours per day, seven days a week.

The Wellington Oro Mine water treatment plant was funded by Summit County Open Space and Trails and the town of Breckenridge. All the detailed civil, mechanical, and electrical engineering was provided by Stantec Inc. Construction was managed by the town of Breckenridge, with general contracting provided by Base Building Solutions, a local construction company. Mechanical work was carried out by Denver-based Bosco Mechanical, and electrical work was done by locally-based Design Electrical Contractors. The underground site piping and mine water collection system work was done by excavation company, BJE, Inc.