Midnite Mine
Encyclopedia
The Midnite Mine is a currently inactive uranium
mine in the Selkirk Mountains
, about eight miles from Wellpinit, Stevens County, Washington. The mine was listed as Superfund
site on 5/11/2000.
Located within the reservation of the Spokane Tribe of Indians
, the mine was operated from 1955 until 1981 was developed and operated by Dawn Mining Company. Dawn is a subsidiary corporation 49 percent owned by Midnite Mines, Inc., a publicly held Delaware corporation originally incorporated by Spokane Tribal members and others. The remaining 51 percent of DMC is held by Newmont Gold, Inc. The property is leased by Dawn from the Spokane Tribe and individual tribal members, and the leases are administered by the United States Bureau of Indian Affairs (BIA). Uranium ore was transported from Midnite Mine to Dawn's mill, some 25 miles east of the mine, just outside the reservation boundary. Mining operations produced approximately 2.9 million tons of ore averaging 0.2 percent uranium oxide. Left behind are some 2.4 million tons of stockpiled ore (containing approximately 2 million pounds of uranium oxide) and 33 million tons of waste rock.
Two open pits, backfilled pits, and a number of waste rock piles and ore 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. Exposed surfaces of rock in ore piles, waste rock piles, and forming pit walls generate acid rock drainage in groundwater, seeps, and surface water. Surface water from the mine's drainage basin flows to three drainages which empty into Blue Creek, a fishery and a spawning and nursery area for fish.
In 2001, the State of Washington determined that the ground water pump-back system was no longer effective in reducing contamination and therefore directed DMC to prepare a Corrective Action Assessment of remediation alternatives. Ground water tests have commenced. The final cleanup plan for the site was issued September 29, 2006.
Uranium mining in the United States
Uranium mining in the United States is the extraction of uranium-bearing ore from the earth. While uranium is used primarily for nuclear power, uranium mining had its roots in the production of uranium-bearing ore in 1898 with the mining of carnotite-bearing sandstones of the Colorado Plateau in...
mine in the Selkirk Mountains
Selkirk Mountains
The Selkirk Mountains are a mountain range spanning the northern portion of the Idaho Panhandle, eastern Washington, and southeastern British Columbia. They begin at Mica Peak near Coeur d'Alene, Idaho and extend approximately 320 km north from the border. The range is bounded on its west,...
, about eight miles from Wellpinit, Stevens County, Washington. The mine was listed as Superfund
Superfund
Superfund is the common name for the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 , a United States federal law designed to clean up sites contaminated with hazardous substances...
site on 5/11/2000.
Located within the reservation of the Spokane Tribe of Indians
Spokane (tribe)
The Spokane are a Native American people in the northeastern portion of the U.S. state of Washington. The Spokane Indian Reservation, at , is located in eastern Washington, almost entirely in Stevens County, but includes two very small parcels of land and part of the Spokane River in...
, the mine was operated from 1955 until 1981 was developed and operated by Dawn Mining Company. Dawn is a subsidiary corporation 49 percent owned by Midnite Mines, Inc., a publicly held Delaware corporation originally incorporated by Spokane Tribal members and others. The remaining 51 percent of DMC is held by Newmont Gold, Inc. The property is leased by Dawn from the Spokane Tribe and individual tribal members, and the leases are administered by the United States Bureau of Indian Affairs (BIA). Uranium ore was transported from Midnite Mine to Dawn's mill, some 25 miles east of the mine, just outside the reservation boundary. Mining operations produced approximately 2.9 million tons of ore averaging 0.2 percent uranium oxide. Left behind are some 2.4 million tons of stockpiled ore (containing approximately 2 million pounds of uranium oxide) and 33 million tons of waste rock.
Two open pits, backfilled pits, and a number of waste rock piles and ore 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
Franklin D. Roosevelt Lake
Franklin D. Roosevelt Lake is the reservoir created in 1941 by the impoundment of the Columbia River by the Grand Coulee Dam in Washington state. It is named for Franklin D. Roosevelt, who was President during the construction of the dam...
. Contaminated water emerging below the waste rock and ore piles is currently captured for treatment in an on-site treatment system. Exposed surfaces of rock in ore piles, waste rock piles, and forming pit walls generate acid rock drainage in groundwater, seeps, and surface water. Surface water from the mine's drainage basin flows to three drainages which empty into Blue Creek, a fishery and a spawning and nursery area for fish.
In 2001, the State of Washington determined that the ground water pump-back system was no longer effective in reducing contamination and therefore directed DMC to prepare a Corrective Action Assessment of remediation alternatives. Ground water tests have commenced. The final cleanup plan for the site was issued September 29, 2006.