Cyprus Tohono Mine Site

AO Bureau

Also Known As


Incident Type




Case Status



Tohono O'odham Reservation


Contaminants of Concern Include

Affected DOI Resources Include

Migratory Birds

Financial Summary

Restoration Funds Collected:


*Restoration Funds Allocated:


*Restoration Funds Remaining:


* 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

The Cyprus Tohono Mine settled a NRDAR case based on releases of hazardous substances into evaporation ponds, a pit lake, and calcine leach residue ponds. Elevated concentrations of arsenic, cadmium, copper, selenium, zinc, sulfuric acid, uranium (as a metal), uranium radionuclides, and adjusted gross alpha activity (a measure of alpha-emitting radionuclides including thorium-230, radium-226, and radon-222) were found in these waters. In addition, other hazardous substances were found present in some source areas.

Case Documents

 Document TypeDocument NameDocument Date


 Factsheet Fact Sheet 10/01/2012


 Consent Decree Consent Decree 07/17/2009


 Restoration Plan Phase I Restoration Plan 12/16/2009
 Restoration Plan and Environmental Assessment Phase II Restoration Plan and Environmental Assessment 07/15/2013
 Restoration Plan and Environmental Assessment Restoration Plan and Environmental Assessment 07/15/2013

Map View

Case Contact

Arizona Ecological Services Field Office

Phoenix, AZ | (602) 242-0210 |

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