The mine has been closed since the late 1950s, and the cleanup is necessary to prevent water and soil contamination. Rio Tinto, which obtained the project after acquiring Alcan in 2007, is managing and paying for the five-year cleanup project, which began in January 2012.

MINING.com took a media tour of the clean up.

The Holden Mine is located in a remote spot near Lake Chelan in north-central Washington State. The village is accessible only via local ferry service on Lake Chelan or by hiking over the Cascade Mountains. The village operates under a Forest Service special-use permit.

To access Holden, a passenger boat takes visitors on a 40-mile trip from Chelan and to Lucerne. After docking there is a 10-mile trip up a hill to Holden village. Between 60-100 people live at Holden Village year-round. Rio Tinto’s clean up work can only occur during the snow free season, which runs generally from May through to October.

All material must be barged in.

The USDA Forest Service, in cooperation with the United States Environmental Protection Agency and the Washington State Department of Ecology, are providing clean up oversight.

Due to the former mine dumping tailings and waste rock on wetlands and near a creek, the U.S. Environmental Protection Agency was prompted to declare the closed mine a Superfund site in the late 1980s. Intalco was responsible for remediating the mine site. Intalco is a successor to the Howe Sound Company.

A spiritual retreat center and community, known as Holden Village, has operated at the site since then, accommodating some 5,000 seasonal visitors a year (most stay one to two weeks). Between 60-100 people live at Holden Village year-round.

Because of the extent of cleanup work, Holden Village plans to adjust its visitor programs for two years during construction. Holden Village will provide a number of services to the project, including accommodation and meals to construction crews during this time.

The parties involved have been working on strategies and agreements for the mine remediation process since the mid-1990s. Some 14 different alternatives for the cleanup effort were studied. The U.S. Forest Service and other state and federal agencies signed off on the cleanup strategy through a Record of Decision issued in late January 2012.

Negotiations with the Forest Service are now underway on the detailed scope of the cleanup process, which is expected to take approximately five years. Rio Tinto is paying for all the clean up.

The Federally-mandated cleanup are addressing the following issues:

Snowmelt and rainwater mix with metals to create acid mine drainage from mine portal, and acid rock drainage (ARD) from tailings and waste rock piles.

ARD affects groundwater and surface water quality, including in Railroad Creek.

While creek water is safe for human consumption downstream of Holden Village, it contains concentrations of hazardous substances that exceed water quality standards for aquatic life.

Slopes of tailings piles are too steep to withstand a large earthquake.

Mine-area soils contain concentrations of natural occurring metals.

The first phase will be completed in 2015 and be followed by several years of water-monitoring. All interested parties will then determine the necessity of a second phase.

Rio Tinto estimates that there will be 370 jobs created over the life of the project, 60% being local. There will also be $30 million in local economic benefits

Note: Michael McCrae’s travel was paid for by Rio Tinto