Midnite Mine

From Wikipedia, the free encyclopedia

The Midnite Mine is a currently inactive former uranium mine in the Selkirk Mountains, about eight miles from Wellpinit, Washington.[1]

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 in Ford, Washington, 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.[2] The final cleanup plan for the site was issued September 29, 2006.[3]

[edit] References

  1. ^ Cornwall, Warren (11/24/2007). Radioactive Remains. Seattle Times. Retrieved on February 24, 2008.
  2. ^ Dawn Mining Company. Washington State Department of Health (4/06/2007). Retrieved on February 24, 2008.
  3. ^ Region 10 Cleanup: Midnite Mine. United States Environmental Protection Agency (11/21/2007). Retrieved on February 24, 2008.