Introduction
Metal mining is the leading source of toxic releases in Alaska.¹ Uncontrolled mine waste, as well as the processing chemicals used to extract the ore, can be a significant source of pollution to the water, land and air. There are five major operating mines in Alaska: Red Dog zinc-lead mine, Fort Knox gold mine, Pogo gold mine, Kensington gold mine and Greens Creek silver mine. This report compiles the track record of spills and the failure to capture and treat wastewater and air pollution at all five mines, and documents associated water quality and other natural resource impacts.
Methods
This report is based on information gathered from an extensive review of state and federal documents, news reports and the federal National Response Center database. It focuses on documenting three failure modes over the life of all five major metal mines operating in Alaska in 2019:
1) Pipeline spills and/or other accidental releases of hazardous materials;²
2) Failure to capture and treat mine impacted water;³ and
3) Failure to capture and treat fugitive dust and air emissions.
Where information is available, it documents the impacts of these failures on natural resources.
Major Findings
- 100% – All five mines have experienced at least one major spill or other accidental release of hazardous materials such as mine tailings, cyanide solution, diesel fuel and ore concentrate.
- 80% – Four of the five mines failed to capture or control contaminated mine water, resulting in water quality violations that often occurred over an extended period.
- 80% – Four out of five mines have been identified by EPA as out of compliance with federal laws to protect clean air or water in the last three years.
- 40% – Metals pollution from two mines has contaminated public lands designated as National Monuments.
- 80% – The Environmental Impact Statement (EIS) process at four of the mines underestimated water quality impacts, failing to predict violations of federal and state laws.
- US EPA, Toxic Release Inventory, Alaska, 2018.
- This failure mode includes pipeline breaks that release mine tailings, processing solutions, or other contaminants. It also includes other accidental releases, such as overtopping of process ponds, and transportation spills.
- This failure mode includes the failure to capture and treat mine impacted waters (e.g., acid mine drainage, cyanide solution, metal-laden waters) that seep from tailings ponds, waste rock piles, heap leach pads or other facilities into surface or groundwater. It also includes discharges from mine treatment facilities that exceed regulatory requirements.