Facility Site ID: 15428546 Cleanup Site ID: 2194

  • Site Status

  • Cleanup Complete-Active O&M/Monitoring
  • Brownfield

  • This site has received funding as part of our Brownfields Program.
    Brownfields Public Funding: $200,000.00

Site Background

The Pend Oreille Mine site is two miles north of Metaline Falls on the east side of the Pend Oreille River.

Teck American Inc. (Teck) owns and operates the Pend Oreille Mine, which is an underground lead and zinc mine. The metals mined there are shipped to their smelter in Trail, British Columbia, Canada (see our Upper Columbia River website for more information). Teck is in the process of permanently closing the mine.

The Pend Oreille Mine cleanup site is two tailings disposal facilities (TDFs), referred to as TDFs 1 and 2, that were used from 1967 and 1977. TDFs 1 and 2 are 18 and 9 acres, respectively.

Teck now uses TDF 3, which is not included in this cleanup and will be addressed during the complete mine closure process.

Investigating Contamination

Click to enlarge site map
Click to enlarge site map

Teck entered into a legal agreement with us in 2005. The agreement required Teck to conduct a supplemental remedial investigation and feasibility study (RI/FS).

The investigation examined the extent of metals contamination in soil, groundwater, and surface water at TDFs 1 and 2. The FS evaluated cleanup options.

Groundwater contaminants found

The investigation showed elevated levels of iron and manganese in groundwater around the TDFs. Groundwater in these areas flows toward the Pend Oreille River. One of the primary purposes of the work at the site is to protect the river and local streams.

Drinking water was not found to be affected by site-related contaminants.

Soil contaminants found

Lead and arsenic in soil around the TDFs exceeded Washington state standards for human health.


Using information from the RI/FS, Ecology wrote a Cleanup Action Plan in 2011, selecting our preferred cleanup options. The consent decree formalized the agreement between Ecology and Teck to complete the cleanup.
The cleanup actions for TDFs 1 and 2 are as follows:
  • Regrade the piles to remove steep slopes and minimize erosion 
  • Compact their surfaces
  • Place protective covers systems over the piles to prevent stormwater from carrying contaminants to groundwater
  • Manage stormwater runoff

In 2023, Ecology visited the site to complete the first periodic review. We conduct a periodic review at least every five years after beginning cleanup at a site. The purpose of the review is to evaluate current site conditions and to ensure the continued protection of people and the environment. We found the cleanup actions continue to protect people and the environment. Groundwater and soil contaminants still exceed Washington standards, but they are contained. No further cleanup is required at this time.

Legal 7
Public Information 3
State Environmental Policy Act 1
Document Title Document Date Document Type
Pend Oreille Mine SEPA Checklist and DNS 2/14/2011 SEPA Documents
Technical Reports 7
Document Title Document Date Document Type
Periodic Review: Pend Oreille Mine 9/18/2023 Periodic Review (5 Year)
Final Compliance Monitoring Plan 3/6/2013 Performance/Confirmational Monitoring Plan or Report
Final Operations and Maintenance Manual TDF1 and TDF2 1/11/2013 Operation and Maintenance Plan
CAP Figures 1-4: Pend Oreille Mine 2/1/2011 Cleanup Action Plan
Cleanup Action Plan: Pend Oreille Mine 2/1/2011 Cleanup Action Plan
Pend Oreille Mine Supplemental Remedial Investigation/Feasibility Study 6/3/2010 Remedial Investigation / Feasibility Study
Pend Oreille Mine- Reclamation Plan Report 9/25/2009 Site Specific Technical Document - other
There may be more documents related to this site. To obtain documents not available electronically, you will need to make a public records request.

Places to see print documents

  • Eastern Regional Office
    N 4601 Monroe St
    Spokane, 99205-1265
    Please schedule an appointment to view print documents at this location.

Contaminants 1

Contaminant Type
Surface Water
Metals - Metals Priority Pollutants C C S
Confirmed Above Cleanup Levels
Below Cleanup Levels
This contaminant list was based on our best information at the time it was entered. It may not reflect current conditions at the site.