Leviathan Mine NPL Site

State TrusteeState TrusteeFederal TrusteeAO Bureau

Also Known As

Incident Type

Mining

State

California

Case Status

Assessment

Location

Leviathan Creek, Bryant Creek, East Fork Carson River

Authority

Contaminants of Concern Include

Affected DOI Resources Include

Migratory Birds

Financial Summary

Restoration Funds Collected:

*Restoration Funds Allocated:

$0.00

*Restoration Funds Remaining:

$0.00

* Restoration Funds can contain multiple settlements/projects. All collections are placed in interest bearing accounts. For detailed information on individual settlements/ projects please visit: NRDAR Status Report

Case Description

Leviathan Mine is an abandoned open-pit sulfur mine high on the eastern slope of the Sierra Nevada, in Alpine County CA. The mine, 24 miles southeast of Lake Tahoe, has been contaminating a nine-mile stretch of mountain creeks. The Toiyabe National Forest surrounds the site, and there are no permanent residents within several miles. The stream system drains into Nevada about five miles from the mine and enters the picturesque Carson Valley nine miles downstream from the mine. Although there had been some mining activities for copper minerals since the 1860s, major environmental problems originated during the open-pit sulfur mining that occurred from 1951 through 1962. During this period, Anaconda used Leviathan Mine as a source of sulfur to dissolve copper from relatively low-grade ore at a mine near Yerington, NV. In 1962 Anaconda ceased operations and sold the property to a local interest. No significant mining activities have taken place since.

The high sulfur content in the waste rocks and fractures at the 250-acre mine site turns snowmelt, rain and groundwater into sulfuric acid, which leaches contaminants from the native minerals such as arsenic, copper, nickel, zinc, chromium along with aluminum and iron. This acid mine drainage then flows into the creek system at a number of points, devastating aquatic life until the creeks join the East Fork of the Carson River, a much larger flow. Except for high flow periods during the spring snowmelt, the acid rock drainage that has been identified produced roughly half of all the flow in Leviathan Creek. Until recent treatment activities, a thick layer of orange precipitate coated the streambed most of the year until it washed into the East Fork with the high spring runoff each year.

The possibility exists that contaminants may be present in greater concentrations in these soils due to discharges from the mine and could pose an increased risk to plants and animals, and even to humans who might use these resources.

Credit: California Dept of Fish and Wildlife


Map View

Case Contact

Central California Agency

Sacremento, CA | (916) 930-3680 | http://www.bia.gov/WhoWeAre/RegionalOffices/Pacific/WeAre/CentralCalifornia/index.htm

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