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EPA PROPOSES TO ADD LAVA CAP MINE TO SUPERFUND LIST
Release Date: 9/24/1998
Contact Information: Lois Grunwald, U.S. EPA, (415) 744-1588
(San Francisco) -- The U.S. Environmental Protection Agency (EPA) announced today that it will propose adding Lava Cap Mine, a former gold and silver mine east of Nevada City, Calif., to the federal Superfund National Priorities List (NPL) of hazardous waste sites. Superfund sites potentially pose the greatest long-term threat to public health and the environment.
Arsenic-contaminated material left over from the mining operations, also known as tailings, was dumped at the mining site and into Little Clipper Creek. Some of the mine tailings also ended up in Lost Lake, which was constructed as an impoundment for the mine tailings in the late 1930s. Arsenic is a known human carcinogen. There have also been mine tailing releases during the last few decades, including a spill after winter storms in 1997.
After the spill in 1997, EPA constructed diversions to reduce the flow of surface water through contaminated areas at the site, stabilized and covered the remaining mine tailings to prevent further spills into Little Clipper Creek. This emergency cleanup work was completed in July 1998. A large amount of mine tailings and waste remain at the Lava Cap site. EPA will assess the extent of contamination at the site and propose cleanup plans. The public will have the opportunity to review all studies on the site and comment on future cleanup plans.
Mining for gold and silver began at the 33-acre Lava Cap site in 1860, and companies operated intermittently at the site until 1943. The ore was taken from underground shafts and crushed into a flour-like material for processing. Cyanide was used in some of the processing.
Listing the site on the NPL will allow U.S. EPA to use federal funds to conduct the cleanup if the former owners are not identified or if they fail to clean up the site. Sites are added to the NPL as part of the periodic review of U.S. hazardous waste sites. U.S. EPA identifies and propose sites to the NPL according to threats to nearby populations through actual or potential contamination of soils, groundwater, surface water or air.