Iron Mountain: An Extraordinary and Extreme Environment
At its peak production, Iron Mountain ranked as the tenth largest copper production site in the world, sixth in the U.S. and first in California. During its operation, from 1879 - 1963, ten different mines throughout the site's 4,400 acres were the source of not just copper, but also silver, iron, gold, zinc and pyrite (iron sulfide).
A century of active mining at Iron Mountain took an environmental toll. The first documented consequence of mining was fish kills in the Sacramento River in 1899, followed by severe air pollution from the open-air heap roasting and smelters that stripped the land of vegetation near the town of Keswick along lower Spring Creek. As mining operations increased, so did pollution. Acid mine water seeping into the Sacramento River, sizable fish kills, and sediment deposits in the Spring Creek Arm of Keswick Reservoir have all plagued the area. To compound the issue, the city of Redding receives its drinking water from the Sacramento River, downstream from the Iron Mountain site. An uncontrolled release of Iron Mountain acid mine drainage could potentially threaten the quality of the drinking-water supply.
Remediation
In 1983, the site was one of the first listed on the U.S. Environmental Protection Agency's National Priority List as part of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or "Superfund"). Its ranking was the third most hazardous site in the State of California. Several successive studies recommended remedial measures to clean up contamination sources at the Iron Mountain site. Starting in 1986, the EPA authorized four Records of Decision (RODs) that enforced specific clean up tasks, such as partial capping, surface-water diversions, tailings removal, and lime neutralization treatment of the most acidic, metal-rich flows, which have reduced copper and zinc loads by 95%.
For further information, see:
Timeline of Mining and Remediation History
Pipe Scale Study
As acidic water at Iron Mountain is transported away from inactive mining sites to a treatment plant, microbial oxidation causes iron in the acid mine drainage to accumulate on the inside of the pipeline, resulting in pipe scale. The encrusted pipes interfere with treatment efforts and cause costly management problems when pipe-scale buildup clogs pipelines and other treatment structures. USGS scientists are working with the EPA to research strategies to prevent or retard scale formation in the pipeline.
Pipe Scale Studies At Iron Mountain Mines >>
Significance of Sulfates
Sulfide oxidation at Iron Mountain has led to extremely acid mine drainage and the active formation of a wide variety of iron-sulfate minerals, including phases identified on Mars. The presence of these sulfates has provided a unique opportunity for scientists to sample associated waters, evaluate water-mineral equilibria, and understand microbes living in these extreme conditions.
Sulfate Minerals at Iron Mountain >>
Connections to Mars Research
The mineralogy at Iron Mountain can serve as a proxy for understanding the formation of iron oxides and sulfates on Mars. The extreme conditions at Iron Mountain provide a unique setting that has allowed significant scientific advances to be made in environmental geochemistry, mineralogy, microbiology, and Mars analog studies.
Iron Mountain and the Red Planet >>
Below are data or web applications associated with this project.
Below are multimedia items associated with this project.
Below are publications associated with this project.
Distribution, thickness, and volume of fine-grained sediment from precipitation of metals from acid-mine waters in Keswick Reservoir, Shasta County, California
The composition of coexisting jarosite-group minerals and water from the Richmond mine, Iron Mountain, California
Major and trace element composition of copiapite-group minerals and coexisting water from the Richmond mine, Iron Mountain, California
Extreme acid mine drainage from a pyritic massive sulfide deposit, the Iron Mountain end-member
Negative pH and extremely acidic mine waters from Iron Mountain, California
Metal exposure in a benthic macroinvertebrate, Hydropsyche californica, related to mine drainage in the Sacramento River
Negative pH, efflorescent mineralogy, and consequences for environmental restoration at the iron mountain superfund site, California
Seasonal variations of Zn/Cu ratios in acid mine water from Iron Mountain, California
Compilation and interpretation of water-quality and discharge data for acidic mine waters at Iron Mountain, Shasta County, California, 1940-91
Stoichiometry of mineral reactions from mass balance computations for acid mine waters, Iron Mountain, California
The production and variability of acid mine drainage at Iron Mountain, California: A superfund site undergoing rehabilitation
Solubility of jarosite solid solutions precipitated from acid mine waters, Iron Mountain, California
At its peak production, Iron Mountain ranked as the tenth largest copper production site in the world, sixth in the U.S. and first in California. During its operation, from 1879 - 1963, ten different mines throughout the site's 4,400 acres were the source of not just copper, but also silver, iron, gold, zinc and pyrite (iron sulfide).
A century of active mining at Iron Mountain took an environmental toll. The first documented consequence of mining was fish kills in the Sacramento River in 1899, followed by severe air pollution from the open-air heap roasting and smelters that stripped the land of vegetation near the town of Keswick along lower Spring Creek. As mining operations increased, so did pollution. Acid mine water seeping into the Sacramento River, sizable fish kills, and sediment deposits in the Spring Creek Arm of Keswick Reservoir have all plagued the area. To compound the issue, the city of Redding receives its drinking water from the Sacramento River, downstream from the Iron Mountain site. An uncontrolled release of Iron Mountain acid mine drainage could potentially threaten the quality of the drinking-water supply.
Remediation
In 1983, the site was one of the first listed on the U.S. Environmental Protection Agency's National Priority List as part of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or "Superfund"). Its ranking was the third most hazardous site in the State of California. Several successive studies recommended remedial measures to clean up contamination sources at the Iron Mountain site. Starting in 1986, the EPA authorized four Records of Decision (RODs) that enforced specific clean up tasks, such as partial capping, surface-water diversions, tailings removal, and lime neutralization treatment of the most acidic, metal-rich flows, which have reduced copper and zinc loads by 95%.
For further information, see:
Timeline of Mining and Remediation History
Pipe Scale Study
As acidic water at Iron Mountain is transported away from inactive mining sites to a treatment plant, microbial oxidation causes iron in the acid mine drainage to accumulate on the inside of the pipeline, resulting in pipe scale. The encrusted pipes interfere with treatment efforts and cause costly management problems when pipe-scale buildup clogs pipelines and other treatment structures. USGS scientists are working with the EPA to research strategies to prevent or retard scale formation in the pipeline.
Pipe Scale Studies At Iron Mountain Mines >>
Significance of Sulfates
Sulfide oxidation at Iron Mountain has led to extremely acid mine drainage and the active formation of a wide variety of iron-sulfate minerals, including phases identified on Mars. The presence of these sulfates has provided a unique opportunity for scientists to sample associated waters, evaluate water-mineral equilibria, and understand microbes living in these extreme conditions.
Sulfate Minerals at Iron Mountain >>
Connections to Mars Research
The mineralogy at Iron Mountain can serve as a proxy for understanding the formation of iron oxides and sulfates on Mars. The extreme conditions at Iron Mountain provide a unique setting that has allowed significant scientific advances to be made in environmental geochemistry, mineralogy, microbiology, and Mars analog studies.
Iron Mountain and the Red Planet >>
Below are data or web applications associated with this project.
Below are multimedia items associated with this project.
Below are publications associated with this project.