Kennecott Mines and Mill Town Site Environmental Investigation Project
Kennecott Mines and Mill Town Site buildings with Bonanza Ridge in the background.
NPS
Kennecott site map.
NPS
Site Background
Kennecott Mines National Historic Landmark, located at the end of the McCarthy Road, encompasses both the Kennecott Mill Town and the mines located in the mountains above the mill. Mining operations at Kennecott occurred between 1901 – 1938. During this period the Kennecott copper mines were among the nation’s richest, containing the last of the great high-grade copper ore deposits in the American West. The world’s first ammonia-leaching plant for extracting copper concentrations from low-grade ores was designed and first successfully used on a commercial scale here. Visitors have guided and unguided access to many of the old buildings and the Kennecott Mill Town also serves as a center for exploring surrounding areas.
Map of Kennecott Mines National Historic Landmark, showing Mill Town buildings and features.
NPS
Collecting water samples from National Creek during the Remedial Investigation in 2021.
NPS
Environmental Investigations
Multiple environmental investigations have been conducted at the Kennecott Mill Town in the past, identifying various potential hazards or risks associated with the historical mining and ore processing operations. Those include the historic use of lead- and arsenic-based paint on buildings; the use of asbestos-containing insulation; the presence of mill tailings containing elevated arsenic; oil and grease spills; and blasting caps and fuses from the historical operations on the north side of the Mill Building and on the moraine west of the Leach Plant.
Because area soils and dust on surfaces both inside and outside of Mill Town buildings contain contaminants such as lead, arsenic, and asbestos, the National Park Service (NPS) recommends that all park visitors and members of the public practice good personal hygiene when in the Mill Town area by keeping hands away from the nose, eyes, and mouth until they can be washed with soap and water. To encourage this, NPS has supplied and maintains hand-washing stations at key locations within the Mill Town, including at the base of the Mill Building (where guided tours exit the building). NPS also maintains signage at several locations within the Mill Town to warn visitors to avoid contact with area soils due to the presence of remaining on-Site contaminants.
Prior to the NPS’s acquisition of the site in 1998, limited cleanup activities were conducted, including packaging and removal of potentially hazardous lab chemicals, batteries, ore processing chemicals, lubricating oils, and transformer oils. Friable asbestos-containing materials have been removed from federally owned Mill Town buildings. The park currently has a lead- and arsenic-based paint mitigation program and has been abating historical paint on an ongoing basis, as well as abating small quantities of additional asbestos discovered during building rehabilitation projects. The areas suspected of containing blasting caps have been fenced and signed for visitor safety.
In 2015, the NPS initiated a Preliminary Assessment(PA) in response to potential releases of heavy metals and other constituents to the environment from historical operations. The PA was based on review of historical reports and documentation as well as a site reconnaissance. Based upon the results of the PA, the NPS determined that a Remedial Investigation/Feasibility Study (RI/FS), pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), was necessary to fully characterize the extent of contamination that may pose a risk to the public and/or the environment and to evaluate remedial measures to address site risks. In 2019, as part of planning and development of the CERCLA RI, NPS conducted an exposure assessment to evaluate potential airborne contamination and fugitive dust exposures to park employees and park visitors. Based upon the results of that investigation, air quality at locations inside and outside of buildings throughout the Mill Town is considered safe and not expected to present a hazard to visitors or park workers.
CERCLA and NPS Authority
NPS is authorized under CERCLA to respond as the Lead Agency to a release or threatened release of harmful substances and/or a release of any pollutant or contaminant that may present an imminent and substantial danger to public health or welfare on or from land under the jurisdiction, custody or control of the NPS. CERCLA provides a thorough site investigation and cleanup framework that can take many years to complete. Additional information regarding the CERCLA cleanup process can be found at the United States Environmental Protection Agency (EPA) website: https://www.epa.gov/superfund/superfund-cleanup-process
All contaminated sites located on lands under NPS jurisdiction go through four phases of cleanup. Each phase of cleanup has specific requirements and milestones based on CERCLA (or the applicable authority). At the Kennecott Mines and Mill Town Site, cleanup phases and milestones are based on CERCLA and its implementing regulations documented in the National Contingency Plan (NCP). The NCP establishes the structure for responding to releases and threatened releases of hazardous substances. Enabling meaningful community involvement throughout the investigation, selection, and implementation of cleanup activities is an ongoing activity and requirement that reaches across all phases of the NPS Cleanup Framework. The NPS approach and key milestones for investigating and cleaning up the Kennecott Mines and Mill Site are listed below.
The NPS is conducting the Remedial Investigation (RI) at the Kennecott Mines and Mill Town Site under CERCLA. An RI is the in-depth study of a contaminated site conducted to characterize the nature and extent of contamination and assess whether the contamination presents a significant risk to human health or the environment. Due to the complexity of the site, the Kennecott Mines and Mill Town Site RI is anticipated to include multiple phases of field work that will include sampling of environmental media (e.g., air, soil, groundwater, surface water, and sediment) to support the evaluation of releases or threatened releases of hazardous substances stemming from the historic mining and ore processing operations.In 2020, the NPS began to scope the Remedial Investigation (RI) activities and develop a Sampling and Analysis Plan (SAP) to guide the on-site RI data collection efforts. On-site sampling is anticipated to occur for several years. After each field season, data gaps will be identified and used to plan the following field season’s sampling activities during the Kennecott Mines and Mill Town Site RI investigation, until the entire site has been characterized for potential contamination. The NPS sampled within the Kennecott Mill Town portion of the site during 2021 and 2023:
Collection of air samples and surficial soil samples to assess ambient outdoor air quality as it relates to fugitive dust emissions.
Collection of surficial soil samples to assess the nature and extent of lead- and arsenic-based paint impacts around current and historical structures.
Collection of surficial soil samples to estimate metal concentrations and the horizontal extent of mill tailings and ore concentrates across the Mill Town.
Collection of surficial soil samples to assess the horizontal extent of blasting cap disposal areas and the concentrations of related contaminants.
Collection of surface water and sediment samples from National Creek (see Community Update - National Creek) and nearby groundwater seeps to assess how site-related contaminants may migrate to and impact surface water and sediment quality.
Next Steps
The following field sampling activities will be conducted during the summer of 2024:
Collection of subsurface soil samples to estimate metal concentrations and the vertical extent of mill tailings and ore concentrates across the Mill Town.
Collection of groundwater from within the Mill Town and from nearby groundwater seeps to assess how site-related contaminants may migrate to groundwater and impact surface water and sediment quality.
Collection of surficial soil samples to assess the nature and extent of lead- and arsenic-based paint impacts around current and historical structures and other potentially impacted areas.
NPS will release a community update prior to the start of the 2024 field sampling season. Once all areas of the site have been thoroughly investigated, a comprehensive site-wide RI report will be prepared to document the results of all field investigation phases and, based upon the data collected, present an evaluation of potential risks to human health and the environment. The results presented in the site-wide RI Report will provide the foundation for how the NPS will evaluate cleanup alternatives in the FS Report to ensure site conditions are protective of human health and the environment and current and potential future site uses. The NPS will then develop a Proposed Plan for public review and comment, which will outline the preferred cleanup option identified for the site. Public feedback will be sought and considered prior to finalization of the Proposed Plan, which will be documented in the site Record of Decision (ROD). Once the ROD is finalized, the NPS will prepare the Remedial Design and commence Remedial Action in all areas of the Kennecott Mines and Mill Town Site determined to require cleanup.
NPS has supplied and maintains hand-washing stations at key locations within the Mill Town, including near the Visitor's Center and at the base of the Mill Building.
NPS
Fenced off area at Kennecott Mill Site.
NPS
Community Involvement
Community Involvement is a very important aspect of the CERCLA process. Community involvement ensures that the members of the public affected by a site undergoing investigation and cleanup under CERCLA, such as the Kennecott Mines and Mill Town Site, have a say in the process, a right-to-know what the agency, NPS, is doing to address the contamination, and provide input into the decision-making process. Early and meaningful communication with affected community members is the goal of the community involvement process, which occurs throughout the lifecycle of the NPS Cleanup Framework. The Community Involvement Plan (CIP) is a resource to enable meaningful community involvement. It serves as a guide for the NPS to inform and engage community members, government officials, the media, and other interested parties in the environmental investigation and cleanup activities at the site. As such, it is a living document that is updated and revised as appropriate, as site conditions and events change. The ways in which the NPS encourages communication with the public are described in detail in the CIP. The CIP and other documents that will be considered or relied upon in the selection of a response action to address the contamination at the site are part of the Administrative Record File.
Electronic copies of documents in the Administrative Record File are available at the bottom of this page. Paper copies are available at the following locations; call for an appointment to review records in person.
National Park Service Alaska Region
240 W 5th Ave Anchorage, AK 99501
Sarah Venator
907-644-3573
Wrangell-St. Elias National Park & Preserve Headquarters
Mile 106.8 Richardson Hwy Copper Center, AK 99573
Benjamin Pister
907-379-0251
Kennecott Visitor Center
Blackburn School, Kennecott, AK 99566
Phone: 907-205-7106
As the Kennecott Mines and Mill Town Site investigation proceeds pursuant to CERCLA, there will be more opportunities for involvement in the process.
To stay informed and engaged you can:
e-mail with questions (click on link) or email to Kennecott_CERCLA@nps.gov
