The Opalite Mine is an inactive mercury mine located on patented mining claims in the extreme southern end of Malheur County, Oregon, approximately 16 miles northwest of McDermitt, Nevada. The mine is surrounded by public land administered by the Vale District of the Bureau of Land Management. The site is approximately 342 acres in size, and the elevation of the site is between approximately 5,200 and 5,400 feet above sea level.
The major site features and potential contaminant sources at Opalite Mine include:
• Burned Ore Piles. Two large burned ore piles with a total volume of approximately 200,000 cubic yards are located on either side of the former processing facilities.
• Ore Processing Facilities. Includes the dilapidated remains of a former rotary furnace and condenser system. The furnace is no longer present.
• Underground Mine Workings. Multiple shafts, adits/tunnels and other underground workings are present, with no evidence of surface water run-off or run-on controls.
• Waste Rock. Several waste rock piles, including 4 known Adits, Waste Rock Piles and the Waste Rock Dump.
• Open Pit/Glory Hole. A large open pit containing exposed mineralized material which could be a source of metals as well as a physical hazard.
Several warning signs previously installed by the Oregon Department of Environmental Quality (DEQ) are present but are in degraded condition. There are no physical access restrictions at the site, and anecdotal evidence and field observations by DEQ indicate that the public may be taking material from the unsecured tailing piles for construction or other aggregate uses. In July 2016, DEQ requested EPA assistance in conducting a removal action to secure the site.
EPA performed a Time-Critical Removal Action at the Opalite Mine Site, August 10 - 21, 2020 to restrict access and prevent the public from removing the mine waste materials from the site.