Commenting open: November 04, 2021 12:00AM PT - December 06, 2021 11:59PM PT.
Silver Mountain Mine Proposed Removal from the Hazardous Sites List
Ecology is providing an opportunity for public review and comment on the proposed removal from the Hazardous Sites List for the Silver Mountain Mine Site, located at County Rd 4371, near Loomis, Okanogan County, Washington.
Ecology provided immediate reduction of risks at the site by neutralizing the cyanide solution in 1981 and removing drums of hazardous material left onsite in 1985. Remedial actions occurred at the site in 1992 under the Environmental Protection Agency (EPA). These remedial actions included consolidation of mined material, closure of the mine entrance, capping of the heap leach pile, fence construction at the site boundary, and hydroseeding throughout the site.
Long-term monitoring is necessary to observe the integrity of the cap and repair as necessary. This will take place through the five-year review process. Institutional controls were also implemented to prevent use of the capped area for any purpose, as well as to restrict use of groundwater from the Site. In September 1997, EPA deleted the site from the National Priorities List.
In October 2021, Ecology determined that no further remedial action is necessary to clean up contamination at the Site and now proposes to remove the site from Ecology’s Hazardous Sites List.
All fields are optional unless otherwise indicated.
Thank you for subscribing to the Silver Mountain Mine Proposed Removal from the Hazardous Sites List mailing list.