Iron Mountain Mine NPL Site

State TrusteeFederal TrusteeAO Bureau

Also Known As

Incident Type

Mining

State

California

Case Status

Restoration

Location

Spring Creek and Sacramento River

Authority

Contaminants of Concern Include

Affected DOI Resources Include

Anadromous Fish, Threatened and Endangered Species, DOI Managed Lands

Financial Summary

Restoration Funds Collected:

$8,039,401.59

*Restoration Funds Allocated:

$9,598,019.51

*Restoration Funds Remaining:

($9,499,647.25)

* 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

From the 1860s through 1963, the 4,400-acre Iron Mountain Mine (IMM) site was mined for iron, silver, gold, copper, zinc, and pyrite. Though mining operations were discontinued in 1963, underground mine workings, waste rock dumps, piles of mine tailings, and an open mine pit still remain at the site. Historic mining activity at IMM has fractured the mountain, exposing minerals in the mountain to surface water, rain water, and oxygen. When pyrite is exposed to moisture and oxygen, sulfuric acid forms. This sulfuric acid runs through the mountain and leaches out copper, cadmium, zinc, and other heavy metals. This acid flows out of the seeps and portals of the mine. Much of the acidic mine drainage ultimately is channeled into the Spring Creek Reservoir by creeks surrounding IMM. The low pH level and the heavy metal contamination from the mine have caused the virtual elimination of aquatic life in sections of Slickrock Creek, Boulder Creek, and Spring Creek.

Credit: USFWS


Case Documents


 Document TypeDocument NameDocument Date

Settlement

 Consent Decree Consent Decree 12/08/2000

Restoration

 Restoration Plan Restoration Plan 04/01/2002

Map View

Case Contact

San Francisco Bay-Delta Fish and Wildlife

Sacramento, CA | (916) 930-5603 | http://www.fws.gov/sfbaydelta/

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