Midnite Mine Superfund Site | Region 10 | US EPA

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Midnite Mine Superfund Site

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Community Resources - Contacts, fact sheets, meetings, comment opportunities

Technical Documents

Maps and Photos

Questions? Please contact us if you have questions or concerns about the site:

Elly Hale (hale.ellie@epa.gov)
Project Manager
206-553-1215

Find more site contacts

Post-decision steps for Midnite Mine superfund cleanup

This graphic shows next steps in the cleanup process following the Record of Decision. We are currently in the "Design the Remedy" step. Click on image for larger view.

Key milestones for Midnite Mine superfund cleanup

Timeline of key milestones in the Superfund cleanup process. The Record of Decision (ROD) for Midnite Mine was finalized in 2006. Click on image for larger view.

Site Summary

Midnite Mine is an inactive former uranium mine in the Selkirk Mountains of eastern Washington. Located within the reservation of the Spokane Tribe of Indians, the mine was operated from 1955 until 1981.

Two open pits, backfilled pits, a number of waste rock piles, and several ore/protore stockpiles remain on site. In addition to elevated levels of radioactivity, heavy metals mobilized in acid mine drainage pose a potential threat to human health and the environment. The site drains to Blue Creek, which enters the Spokane Arm of Franklin D. Roosevelt Lake. Contaminated water emerging below the waste rock and ore piles is currently captured for treatment in an on-site treatment system.

After a study of the site, EPA sought public comment on a proposed cleanup plan in September 2005. The final cleanup plan for the site is described in the Record of Decision, or ROD, issued September 29, 2006.

Under a 2008 EPA order, Newmont Mining Co. and Dawn Mining Co. fenced the site and and performed initial design studies. Design work and site cleanup up will continue under a legal agreement called a consent decree, finalized in January, 2012.

Cleanup design elements being discussed

Planning for the cleanup of Midnite Mine has been in the works for several years. Dawn and Newmont (the mining companies involved with Midnite Mine) have submitted a preliminary cleanup design to EPA for review. Learn more about next steps and how to provide input »

Download a copy of the preliminary design and appendices »

Download a copy of the drawings associated with the preliminary design »

Public Health Assessment

A public health assessment conducted in 2010 by the federal Agency for Toxic Substances and Disease Registry (ATSDR) suggests that residents should not:

  • use water from seeps, drainages, or Blue Creek for drinking or sweat lodge ceremonies;
  • gather plants in or along mine drainages and Blue Creek in the mining-affected area;
  • consume fish from Blue Creek;
  • eat the organs, especially the liver and kidneys, from deer, elk, or other big game harvested in or near the Blue Creek drainage area.

Read the full ATSDR Public Health Assessment for Midnite Mine (PDF) (153 pp, 3.7MB) - May 2010

Aerial Radiation Survery of the Spokane Reservation

In September 2011, EPA conducted an aerial survey of the Spokane Reservation to follow up on questions about sources of radiation outside Midnite Mine. A small plane with ‘US EPA’ painted on the bottom of its wings, flew over the areas of interest at 500 ft above the ground. Equipment on the plane gathered data on radiation levels in various locations including populated areas, Midnite Mine, the Dawn Mill, and the Western Nuclear/Sherwood mine/mill.

Cleanup Plan

EPA's cleanup plan - called a Record of Decision - calls for a cap over an area of pits filled with waste during mining, consolidation and engineered containment of remaining waste in the two open pits, removal of water entering the pits, and operation of a treatment system to treat contaminated water from the pits and seeps.

Design of the cleanup includes data collection to support detailed construction plans and is expected to be finished in several years.

Who pays for the cleanup?

EPA's policy is to have the responsible parties - also called Potentially Responsible Parties, or PRPs - pay for cleaning up pollution. Responsible parties can be past or present operators and land owners.

Under a legal agreement called a consent decree, Dawn Mining Company, LLC, and Newmont USA Limited will complete the cleanup work, and the United States will contribute a share of the cleanup costs. EPA will oversee the cleanup work in coordination with the Spokane Tribe.


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