EPA Issues Final Cleanup Decision for Midnite Mine Superfund Site

Release date: 10/03/2006

Contact Information: Ellie Hale, 206-553-1215, hale.ellie.epa.gov Mark MacIntyre, 206-553-7302, Macintyre.mark@epa.gov

(Seattle, WA – Oct. 3, 2006) - The U. S. Environmental Protection Agency Region 10 (EPA) has selected a final cleanup plan for the Midnite Mine Superfund Site near Wellpinit, Washington The Record of Decision (ROD) was signed by EPA’s regional superfund director Dan Opalski in Seattle.

The Midnite Mine Superfund Site (Site) is an inactive open-pit uranium mine located on the Spokane Indian Reservation in eastern Washington, approximately 45 air miles northwest of Spokane. Uranium mining from the mid-50s through the early 80s left two open pits, piles of uranium-bearing rock at the surface, and an area of waste-filled pits. The ROD serves as a legally enforceable framework and roadmap for actions that will be taken to reduce potential health risks at the site

According to Dan Opalski, Director of EPA’s Region 10 Office of Environmental Cleanup in Seattle: “After a thorough analysis of options, we believe we've arrived at the best solution for a tough problem. We can't erase 25 years of mining impacts, but this cleanup will protect the health of the community and the surrounding environment.”

The ROD addresses all contaminated materials at the Site. This includes waste materials in the 350 acre mined area and mining-affected groundwater, surface water, soils, and sediments. Specifically, final cleanup includes actions such as:

• Engineered containment of above-grade mine waste in the two open pits, Pit 3 and Pit 4.

• Construction of a soil cap over waste contained in Pits 3 and 4, and over waste in a previously backfilled pit area.

• Removal and treatment of water that enters Pit 3, Pit 4, and the Backfilled Pit Area.

• Continued collection and treatment of contaminated seeps.

• Design and construction of a replacement water treatment plant.

• Long-term discharge of treated water to the Spokane River Arm (of Lake Roosevelt) under a future NPDES permit.