sť United States Environmental Protection Agency National Priorities List (NPL) ** *NPL Site *** AFTERTHOUGHT MINE Bella Vista, California Shasta County OLEM/OSRTI Washington, DC 20460 September 2024 (?) Site Location: The Afterthought Mine is located in Bella Vista, Shasta County, California. The site lies on the eastern bank of Little Cow Creek along California State Highway 299 and is approximately 25 miles northeast of the city of Redding. Site History: The Afterthought Mine is an inactive abandoned mine that was discovered in 1862. The site produced copper, zinc, lead, silver, and gold from approximately 1873 through 1952. Remnants of historic mining activities remain onsite, including: unstable structures, mining debris, multiple waste rock piles, adits, and portals. From 1900 to 1952, 166,424 tons of ore were mined from Afterthought Mine. Production included 10,730,580 pounds of copper, 23,635,840 pounds of zinc, 1,738,300 pounds of lead, 923,653 ounces of silver, and 4,992 ounces of gold. A former and inactive smelter associated with the Afterthought Mine during its time of operation, called the Afterthought Smelter, is located approximately one mile downstream from the mine site. 1 Site Contamination/Contaminants: Downstream of the site, the surface water and sediments in Little Cow Creek are contaminated with cadmium, copper, and zinc at levels approximately 100 times, 1200 times, and 1000 times, respectively, above the California Toxics Rule Water Quality Criteria for acute risk. The Afterthought Mine is a source of metals contamination from waste rock, acid mine drainage, and tailings generated from historic mining and smelting activities. Acid mine drainage discharges from a mine portal into Afterthought Creek, which flows directly into Little Cow Creek. Tailings with elevated concentrations of metals including arsenic, cadmium, copper, lead, mercury, and zinc were observed in direct contact with Little Cow Creek. rtft Potential Impacts on Surrounding Community/Environment: The site can be accessed via Little Cow Creek during low flow and is not fenced on the western boundary next to Highway 299. Little Cow Creek is used for fishing, provides wetland habitat, and is a designated critical habitat for steelhead trout downstream of the site. Adits, portals, unstable structures, and shafts at the mine site pose a physical hazard. Fishing on Little Cow Creek includes largemouth bass, smallmouth bass, Chinook salmon, brown trout, brook trout, and rainbow trout. Discarded fishing tackle has been observed along Little Cow Creek around the mine area. ^ Response Activities (to date): There have been no response activities by the EPA or the state of California to date. B Need for NPL Listing: The state of California referred the site to the EPA because of the acid mine drainage discharging into Little Cow Creek, and tailings remain in direct contact with Little Cow Creek. Other federal and state cleanup programs were evaluated, but no other program has the appropriate authorities or resources to address the site at this time. The EPA received a letter of support for placing this site on the NPL from the state of California. [The description of the site (release) is based on information available at the time the site was evaluated with the HRS. The description may change as additional information is gathered on the sources and extent of contamination. See 56 FR 5600, February 11, 1991, or subsequent FR notices.] For more information about the hazardous substances identified in this narrative summary, including general information regarding the effects of exposure to these substances on human health, please see the Agency for Toxic Substances and Disease Registry (ATSDR) ToxFAQs. ATSDR ToxFAQs can be found on the Internet at https://www.atsdr.cdc.gov/toxfaqs/index.asp or by telephone at 1-800-CDC-INFO or 1-800-232-4636. ------- |