The NPL is a list of known sites throughout the United States and its territories where historic releases of hazardous substances, pollutants or contaminants pose significant threats to human health and the environment.
Afterthought Mine operated from 1862 to 1952, producing copper, zinc, lead, silver, and gold. Historic mine features and structures remain onsite, and these mining efforts contaminated the site’s soil and nearby waterways. Contaminated soil and sediment are in direct contact with Little Cow and Afterthought creeks.
Little Cow Creek is used for fishing and provides wetland habitat including critical habitat for steelhead trout. EPA will evaluate these areas to better understand the contamination, and if and how the Agency can clean it up.
“The proposal of Afterthought Mine to the National Priorities List is a vital step in EPA’s work to assess contamination in the area and how best to address it,” said EPA Pacific Southwest Regional Administrator Martha Guzman. “Cleaning up contaminated land and water and returning them for productive use to communities, especially those which have borne the brunt of legacy pollution, is a win for public health and local economies.”
EPA is accepting comments on the proposal to add the Afterthought Mine to the Superfund NPL from March 7 until May 6, 2024. The public can submit comments online or by mail:
Online (preferred): Visit www.regulations.gov and search “Afterthought Mine” or “EPA-HQ-OLEM-2024-0066”
Mail: Send comments to:
U.S. Environmental Protection Agency, EPA Docket Center Superfund, [EPA-HQ-OLEM-2024-0066], Mail Code 28221T, 1200 Pennsylvania Avenue, NW, Washington, DC 20460
The National Priorities List includes sites with the nation’s most serious uncontrolled or abandoned releases of contamination. This list serves as the basis for prioritizing EPA Superfund cleanup funding and enforcement actions. Only releases at non-federal sites included on the National Priorities List are eligible to receive federal funding for long-term, permanent cleanup.
Before EPA adds a site to the National Priorities List, a site must meet EPA’s requirements and be proposed for addition to the list in the Federal Register, subject to a 60-day public comment period. EPA may add the site to the National Priorities List if it continues to meet the listing requirements after the public comment period closes and the agency has responded to any comments.
Superfund cleanups provide health and economic benefits to communities. The program is credited for significant reductions in both birth defects and blood-lead levels among children living near sites, and research has shown residential property values increase up to 24 percent within three miles of sites after cleanup.
Since taking office, the Biden-Harris Administration has followed through on commitments to update the National Priorities List twice a year, as opposed to once per year. Today’s announcement is the first time EPA is updating the National Priorities List in 2024.
Learn more about Superfund and the National Priorities List.
For Federal Register notices and supporting documents for the National Priorities List and proposed sites, please visit New Proposed and New Superfund National Priorities List Sites.
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