Pacific Southwest, Region 9: Superfund
Serving Arizona, California, Hawaii, Nevada, the Pacific Islands, and Tribal Nations
Celtor Chemical Works
EPA #: CAD980638860
Congressional District: 01
Other Names: Hoopa Valley Indian Reservation
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Description and History
NPL Listing History
NPL Status: Final
Proposed Date: 12/30/82
Final Date: 09/08/83
Deleted Date: 09/30/03
The 3.2-acre Celtor Chemical Works site, located in the northern Hoopa Valley Indian Reservation, is a former ore concentrating facility that processed sulfide ore for copper, zinc, and precious metal extraction. The Hoopa Valley Indian Tribe, the site's owner, leased the land in 1958 to the Celtor Chemical Corporation. From 1958 until 1962, copper, zinc, and precious metals were recovered on site from sulfide ore mined and trucked to Celtor from the nearby Copper Bluff Mine. In 1962, Celtor Chemical Corporation abandoned the site and mine tailings generated from the milling operations were left on site. These tailings, along with non-specific releases of processed ore, were thought to be the cause of the acidic surface water runoff and elevated metals concentrations in the soils throughout the site. The site consists of the plant, an adjacent pasture used for grazing livestock, a gully connecting the plant and the Trinity River, a drainage creek that collects surface runoff and carries it into the Trinity River, and a fishing access road that is frequently used by local residents. There are approximately 200 people living within one mile of the site. The Trinity River, which supports the only fish resources for the Hoopa Indians, flows through the center of the reservation and near the site.
Contaminants and Risks
- Soil and Sludges
Soil was contaminated with heavy metals including arsenic, copper, lead, cadmium, and zinc. Potential health threats to people included accidental ingestion or inhalation of contaminated soil and dust generated by wind.
Immediate Actions: In 1983, the EPA conducted a focused feasibility study. After a public comment period, EPA signed a Record of Decision on October 4, 1983 to conduct a time critical removal action. By December, 1983, EPA had excavated 1400 cubic yards of visibly contaminated materials. This material included tailings, non-concrete structures, and a portion of the pasture adjacent to the site. The main portion of the site was fenced, and the access road was covered with gravel. The flow of several springs was diverted away from the contaminated areas and into a nearby creek, which emptied into the Trinity River. During this cleanup action, additional contamination was discovered in locations not previously identified, so EPA conducted a more detailed investigation.
Entire Site: On September 30, 1985, EPA signed a Record of Decision that selected a more complete remedy to clean up the Celtor Chemical Works site. From October 1987 to the final off-site shipment in October 1988, the EPA excavated an additional 1,200 cubic yards of contaminated material from the site and disposed of them off site at an EPA-approved hazardous waste disposal facility. Backfilling, contouring of the land and revegetation activities were also completed in 1988 followed by a one-year post remedial maintenance period.
To ensure that cleanup actions remained protective of human health and the environment, EPA conducted five-year reviews published on September 30, 1993 and August 29, 2001. To resolve some uncertainties identified in the review and address community concerns, EPA took samples of site soils in May, 2003. A total of 38 soil samples and five surface water samples were taken to ensure that no contaminants of concern remained on the site above cleanup goals. Sample results confirmed that the site was free of contaminants above cleanup goals. Therefore, EPA concluded that the soils do not pose an unacceptable health hazard for residential or unrestricted land use. In 2006, EPA scientists formally certified that the entire site is ready for unrestricted reuse.
Cleanup Results to Date
The EPA has completed all actions for the cleanup of contamination at the Celtor Chemical Works site. The EPA, in conjunction with the State and Tribe, determined that the site meets human health and environmental goals.
The site no longer poses a threat to human health or the environment. The site was deleted from the NPL on September 30, 2003.
Potentially Responsible Parties
Potentially responsible parties (PRPs) refers to companies that are potentially responsible for generating, transporting, or disposing of the hazardous waste found at the site.
Online information about the PRPs for the site is not yet available.
Documents and Reports
Public Information Repositories
The public information repositories for the site are at the following locations:
EPA Site Manager
75 Hawthorne Street
San Francisco, CA 94105
EPA Community Involvement Coordinator
75 Hawthorne Street
San Francisco, CA 94105
EPA Public Information Center
After Hours (Emergency Response)