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National Oil and Hazardous Substance Pollution Contingency Plan; National Priorities List

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Environmental Protection Agency.


Notice of intent to delete the Celtor Chemical Works Superfund Site from the National Priorities List.


The Environmental Protection Agency (EPA) Region IX is issuing a Notice of Intent to Delete the Celtor Chemical Works Superfund Site (Site) located in Hoopa, California, from the National Priorities List (NPL) and requests public comments on this Notice of Intent to Delete. The NPL, promulgated pursuant to section 105 of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), as amended, is found at appendix B of 40 CFR part 300, which is the National Oil and Hazardous Substances Pollution Contingency Plan (NCP). The EPA, Hoopa Valley Tribe and the State of California, through the California Department of Toxic Substances Control (DTSC), have determined that all appropriate response actions under CERCLA have been completed. However, this deletion does not preclude future actions under CERCLA.


Comments concerning this Site must be received by September 17, 2003.


Written comments should be addressed to: Beatriz Bofill, Remedial Project Manager, U.S. EPA, Region IX, SFD-7-2, 75 Hawthorne Street, San Francisco, CA, 94105-3901, (415) 972-3260 or (800) 231-3075.

Information Repositories: Comprehensive information on this Site Start Printed Page 49407is available through the Region IX public docket which is available for viewing at the EPA Region IX Superfund Records Center, 95 Hawthorne Street, San Francisco CA, 94105-3901, (415) 536-2000 (Monday through Friday 8 a.m. to 5 p.m.); Hoopa Valley Tribal EPA, P.O. Box 1348, Hwy 96, Hoopa, CA 95546, (530) 625-5515.

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Beatriz Bofill, Remedial Project Manager, U.S. EPA, Region IX, SFD-7-2, 75 Hawthorne Street, San Francisco, CA 94105-3901, (415) 972-3260 or (800) 231-3075; or Hector Aguirre, Community Involvement Coordinator, U.S. EPA, Region IX, SFD-3, 75 Hawthorne Street, San Francisco, CA 94105-3901, (415) 972-3238 or (800) 231-3075.

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Table of Contents

I. Introduction

II. NPL Deletion Criteria

III. Deletion Procedures

IV. Basis for Site Deletion

I. Introduction

The U.S. EPA Region IX is publishing this Notice of Intent to Delete the Celtor Chemical Works Superfund Site from the NPL and requests public comment on this proposed action. The NPL constitutes appendix B of 40 CFR part 300, which is the National Oil and Hazardous Substances Pollution Contingency Plan, which EPA promulgated pursuant to Section 105 of CERCLA, as amended. The EPA identifies sites that appear to present a significant risk to public health, welfare, or the environment, and maintains the NPL as the list of those sites. As described in § 300.425(e)(3) of the NCP, sites deleted from the NPL remain eligible for remedial action in the unlikely event that conditions at the site warrant such action.

EPA will accept comments on the proposal to delete this Site for thirty (30) days after publication of this document in the Federal Register.

Section II of this document explains the criteria for deleting sites from the NPL. Section III discusses procedures that EPA is following specifically for this Site. Section IV discusses the Celtor Chemical Works Superfund Site and demonstrates how it meets the deletion criteria.

Deletion of a site from the NPL does not itself create, alter, or revoke any individual's rights or obligations.

II. NPL Deletion Criteria

Section 300.425(e) of the NCP provides that sites may be deleted from the NPL where no further response is appropriate. In making a determination to delete a site from the NPL, EPA, in consultation with the State and the Tribe, shall consider whether any of the following criteria have been met:

i. Responsible parties or other persons have implemented all appropriate response actions required; or

ii. All appropriate Fund-financed (Hazardous Substance Superfund Response Trust Fund) response under CERCLA has been implemented, and no further response action by responsible parties is appropriate; or

iii. The remedial investigation has shown that the release poses no significant threat to public health or the environment and, therefore, the taking of remedial measures is not appropriate.

If new information becomes available which indicates a need for further action, EPA may initiate remedial actions. Whenever there is a significant release from a site deleted from the NPL, the deleted site may be restored to the NPL without application of the Hazard Ranking System (40 CFR 300.425(e)(3)).

III. Deletion Procedures

The following procedures apply to deletion of this Site:

(1) All remedial action has been implemented as is documented in the Final Close Out Report (FCOR), dated September 29, 1989.

(2) The EPA consulted with the State of California and the Hoopa Valley Indian Tribe on the deletion of the Site from the NPL prior to developing this Notice of Intent to Delete.

(3) The Hoopa Valley Indian Tribe concurred with deletion of the Site from the NPL.

(4) The State of California concurred with deletion of the Site from the NPL.

(5) A notice has been published in the local newspaper and has been distributed to appropriate federal, state, and local officials and other interested parties announcing the commencement of a 30-day public comment period on EPA's Notice of Intent to Delete.

(6) The EPA placed copies of documents supporting the deletion in the Site information repositories identified above.

For deletion of this Site, EPA's Regional Office will accept and evaluate public comments before making a final decision to delete. If comments are received, EPA will prepare a Responsiveness Summary to address those comments. The Responsiveness Summary will be available for review in the Deletion Docket. The Deletion Docket is a compilation of documents containing all pertinent information supporting the deletion recommendation.

A deletion occurs when the Regional Administrator places a final notice in the Federal Register. Generally, the NPL will reflect deletions in the final update following the notice. Public notices and copies of the Responsiveness Summary will be made available to local residents by the Regional Office in the local information repository and in the Region IX Superfund Records Center.

IV. Basis for Site Deletion

The following information provides EPA's rationale for deleting the Site from the NPL:


The Celtor Chemical Works Superfund Site is a 2.5 acre parcel of mountainous terrain located at the northern end of the Hoopa Valley Indian Reservation in Humboldt County California, about 2 miles north of the town of Hoopa. The property on which the Site is located is owned by the Hoopa Valley Indian Tribe. The Tribe's land is held in trust by the U.S. Bureau of Indian Affairs (BIA). The land use for the area surrounding the Site is rural residential. A cattle grazing pasture is located to the west of the former plant site. A gravel bar on the Trinity River at the northern end of the Site provides access to a popular recreational fishing site.

In 1958, BIA leased the land to the Celtor Chemical Corporation on behalf of the Tribe. The Celtor Chemical Corporation processed sulfide ore taken from the Copper Bluff Mine. The plant, known as the Celtor Chemical Works Mill, is believed to have used dissolved air flotation to extract copper, zinc, and precious metals from the ore. The ore concentrates were trucked off-site for further processing. Some mine tailings were stockpiled in the area of the plant site; however, most of the tailings were presumably sluiced down a drainage ditch to the Trinity River. The tailings may have been the cause of the numerous fish kills for which the California Department of Fish and Game have cited the Celtor Chemical Corporation.

In 1960 the Celtor Chemical Corporation became delinquent in its royalty payments to the Hoopa Valley Indian Tribe. By 1962, Celtor ceased operations and in March 1993, the BIA, as trustee for the Tribe, canceled the leases of both the Copper Bluff Mine and the Celtor Chemical Works Mill.

After milling operations ceased, a very large pile of tailings was reported to have been left standing on a sand and gravel bar between the drainage ditch and the Trinity River, along with the tailings that were known to have been Start Printed Page 49408left at the plant site. Flooding in 1964 reportedly washed all traces of tailings that had been left on the sand and gravel bar into the Trinity River.

Acid runoff from the Site continued to leach the remaining tailings in the plant area. Elevated levels of metals in Site soils were identified in samples collected by the California Department of Health Services in July 1981. In August of the same year, EPA received a Notification of a Hazardous Waste Site under the Comprehensive Environmental Response, Compensation and Liability Act of 1980 (CERCLA) from the State. The Site was placed on the California State Priority List in April 1982, then included on the National Priorities List (NPL) in September 1983.

Initial Response

In December, 1983, EPA completed a Removal Action (also called the initial remedial measure) in which all visibly contaminated material (tailings, non-concrete structures, and a portion of the adjacent pasture) were removed. Approximately 1,400 cubic yards of contaminated material were taken to the IT Corporation Class I hazardous landfill in Benicia, California.

Remedial Investigation and Feasibility Study (RI/FS)

The Remedial Investigation/Feasibility Study was completed on June 28, 1985, and a Record of Decision (ROD) was signed by the Regional Administrator on September 30, 1985, which selected excavation and off-site disposal of the remaining contaminated soils.

Remedy Selection

The ROD for the Celtor Chemical Works Site was signed on September 30, 1985. The primary human health threats posed at the Site were (1) direct contact with soils contaminated with arsenic, copper, cadmium and lead, and (2) consumption of surface water runoff from the Site or in the drainage ditch, which sometimes exceeded Maximum Contaminant Levels for copper, iron, lead and zinc. The remedial action objective was to prevent human exposure to soil and water contaminated with arsenic, copper, cadmium, zinc, mercury, selenium, cyanide and lead at concentrations that may pose a public health or environmental threat.

The remedial actions of the 1985 ROD were: demolition and removal of structures, excavation of soils contaminated above action levels from all Site areas, import clean fill as necessary, regrade and vegetate the Site, and install security fencing to protect new vegetation. No groundwater treatment was necessary because the aquifer was not contaminated.

Following signature, the ROD was amended twice. The first amendment corrected an error in the copper action level and the second amendment added additional standards for mercury, selenium, and cyanide in soils. The additional cleanup standards were added as precautionary measures; subsequent sampling showed all three metals to be below action levels.

Remedy Implementation

In August 1986, EPA entered into an interagency agreement (IAG) with the U.S. Army Corps of Engineers for the remedial design. The Corps retained Aqua Resources, Inc. of Berkeley to plan the remedial action.

The remedial design was completed by Aqua Resources, and approved by EPA on June 9, 1987. The design plan was divided into six areas designated A-F to be excavated to various depths. After excavation, soil samples were to be taken at designated grid points for all the contaminants of concern. It was estimated that 3,220 yards of soil and 890 tons of concrete were to be removed and transported to the Envirosafe Services RCRA approved Class I Landfill in Grandview, Idaho. Environmental Health Research and Testing, Inc. (EHRT) was contracted to carry out the remedial action work. Shortly into the remediation, EHRT submitted a Value Engineering Change Proposal (VECP) to perform deeper and more thorough sampling to reduce the volume of soils excavated. This change was accepted and decreased the actual volume of soil excavated and transported to the Idaho Class I landfill to 1,163 cubic yards. Another post-design change was in the sampling depth of the concrete.

On December 9, 1987 the Site was closed down for the winter season, and activities resumed again on May 11, 1988. All backfilling and revegetation was completed on October 14, 1988, marking the beginning of a one year post-remedial maintenance period.

At any location where contaminants were detected above action levels, additional soil was excavated and removed to the approved off-site landfill. The removal of contaminated material and subsequent confirmatory sampling of remaining on-site soils ensured that all contamination was removed from the Site according to the guidelines set forth in the Quality Assurance Project Plan (QAPP). On February 20, 1989, the Corps sent the Final Technical Report to EPA describing all of the construction activities and the sampling data.

Operation and Maintenance

The operation and maintenance (O&M) was performed for a one-year period by the U.S. Army Corps of Engineers. O&M efforts included monthly site visits to inspect for evidence of erosion and problems with revegetation, and maintenance of the perimeter fence.

Five-Year Review

The initial Five Year Review conducted in 1993 found the Site to be in good condition, with a healthy cover of vegetation and no evidence of erosion. A wood-staked wire fence had been constructed around the pasture which had been remediated during the remedial action. The 1993 review concluded that the Site required little or no maintenance. However, the Hoopa Valley Indian Tribe subsequently raised concerns about residual contamination remaining at the Site. On September 20, 1995, EPA collected 14 biased samples from the Site at the request of the Hoopa Tribe. Samples were collected from three distinct areas of the Site, including the former facility hillside, the access road leading down to the river, and the gravel bar between the drainage ditch and the Trinity River where it was reported a large pile of mine tailings had once stood before they were washed away by the 1964 flood. Of the 14 samples, 4 samples had levels of contaminants above the ROD clean-up goals.

On April 22, 1996, EPA's Emergency Response Team performed additional, more extensive sampling at the Site to verify that the cleanup was complete. A total of 26 soil and sediment samples were collected and analyzed by screening with the x-ray fluorescence (XRF) spectrometer, and six soil samples were sent to a lab for confirmatory analysis. Soils were also analyzed for pH. Hillside soil samples from the former plant site contained minimal levels of copper, and traces of copper were also found in the river access road cut area and the drainage ditch but samples at both sites were well below action levels for the Site. No detectable contamination was found in samples collected from the borrow pit. However, analysis of samples collected from stained areas on the gravel bar indicated these sediments may have levels of copper, lead and arsenic in excess of the cleanup level.

Since 1996 no stained sediments have been observed on the gravel bar by EPA or the Tribe. The gravel bar, hillside, and gully that connects the Site to the Trinity River were sampled in 2002. No Contaminants of Concern (COCs) were Start Printed Page 49409found in concentrations above ROD cleanup goals.

A Second Five-Year Review was conducted in August of 2001. The review concluded that the Site was not currently a threat to human health and the environment, but that additional data was needed to determine if the Site posed a future risk. The Review concluded that all items of concern would be resolved before delisting could occur.

EPA, with support from the Tribal Environmental Protection Agency (TEPA), conducted a comprehensive unbiased sampling event on May 28, 2003. EPA sampled the hillside, drainage ditch adjacent to the hillside, and gully that connects the Site to the Trinity River. A total of 38 soil samples were taken and 4 surface water samples were taken. The laboratory results from the sampling indicated that all sampled constituents are below the levels established in the ROD.

These results have been reviewed by the Region IX EPA toxicologist who concurs that the Site has met soil action levels established in the ROD, and that the Site does not pose an unacceptable risk to human health or the environment from the COCs based upon EPA's current guidance.

EPA has determined that all appropriate response actions for the COCs have been implemented, and the Site is available for unrestricted use. Therefore, no more Five-Year Reviews need to be conducted at the Site.

Community Involvement

During the week of August 4, 2003, a fact sheet was mailed out to tribal members notifying them of EPAs intent to delete the site from the NPL. In addition to the fact sheet, an announcement for a community meeting was published in a local paper on August 5, 2003. The community meeting is scheduled for August 13, 2003. Members of the community will be invited to ask questions and make formal comments. The Deletion Docket which contains the documents EPA relied on for its recommendation to delete the Site from the NPL is available to the public in the information repositories.

Applicable Deletion Criteria/State Concurrence/Tribal Concurrence

All the completion requirements for this Site have been met as described in the FCOR dated September 28, 1989. The NPL provides that a site is eligible for deletion where “all appropriate Fund-financed (Hazardous Substance Superfund Response Trust Fund) response under CERCLA has been implemented, and no further response action by responsible parties is appropriate,” and where “responsible parties or other parties have implemented all appropriate response actions required.”

EPA, with the concurrence of the Hoopa Valley Indian Tribe through the Tribal EPA on November 26, 2003 and the State of California through its Department of Toxic Substances Control on July 25, 2003, and finds that these criteria for deletion of the Site have been met. Consequently, EPA is proposing deletion of the Celtor Chemical Works Superfund Site from the NPL.

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Dated: August 7, 2003.

Deborah Jordan,

Acting Regional Administrator, Region IX.

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[FR Doc. 03-20778 Filed 8-15-03; 8:45 am]