Zortman-Landusky Gold Mine, Montana

The Zortman Landusky gold and silver mine is located in the Little Rocky Mountains of north central Montana, just south of the Fort Belknap Reservation - home to the Gros Ventre and Assiniboine Tribes.

Cyanide Spill Contaminates Drinking Water

The mine has caused extensive surface and groundwater contamination.  Over the course of operations, the mine has experienced over a dozen cyanide spills, including one spill that released 50,000 gallons of cyanide solution and contaminated a community drinking water supply.

The mine also developed a serious acid mine drainage problem as it began to mine environmentally risky sulfide ores.  In the early 1990s the State of Montana, the Fort Belknap Tribes and the Environmental Protection Agency filed suits against the company for impacts to water resources due to long-term water quality violations, including cyanide, acids and metals.

In 1997, in response to the lawsuits, the company agreed to construct an additional water treatment plant, to study environmental damage to the groundwater, and to increase water quality monitoring.

Bankruptcy Leave $33 Million in Clean-Up Costs

In 1998, the company filed for bankruptcy, leaving the state of Montana with the liability for $33 million in long-term water treatment and reclamation costs.  The state has determined that water pollution generated by the mine is so severe that expensive water treatment systems will have to be operated forever.

In 2003 the Fort Belknap tribes filed suit under the Clean Water Act again because the defunct mine site has continued to discharge toxic pollutants into water resources.