EPA Settles 2 Hazmat Cleanup Cases

According to the U.S. Environmental Protection Agency Columbia Falls Aluminum Company, LLC (CFAC) has agreed to clean up contamination at the Anaconda Aluminum Company Columbia Falls Reduction Plant Superfund site near Columbia Falls, Montana, also called the CFAC site.  A separate agreement resolves Denka Performance Elastomer’s failure to properly manage and handle chloroprene waste.

In Montana, CFAC agreed to pay past response costs and implement multi-million-dollar cleanup actions at the site.

Under the proposed consent decree, EPA and the Montana Department of Environmental Quality will oversee the design and the implementation of remedial activities to address arsenic, cyanide, fluoride, and polyaromatic hydrocarbon (PAH) contamination. The cleanup activities are outlined in the Record of Decision, which was signed by EPA and DEQ in January 2025.  

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“This consent decree represents a significant milestone on the path to successful cleanup and redevelopment,” said EPA Region 8 Regional Administrator Cyrus Western. “In coordination with our federal, state, local, and industry partners, EPA is advancing effective, protective solutions that safeguard human health and the environment.” 

After the public comment period and court approval of the proposed consent decree, CFAC will design and implement the cleanup work, known as the remedial design/remedial action under EPA and DEQ oversight. 

“In partnership with EPA, we are excited to announce this consent decree, allowing for the successful cleanup and redevelopment of the Columbia Falls Aluminum Company Superfund site,” said Montana DEQ Director Sonja Nowakowski. “We are happy that we continue to work with the EPA and the community to ensure this work will protect the Flathead River and Columbia Falls.”  

“The start of active cleanup activities is a positive step toward addressing environmental impacts at the site and reflects a shared commitment by CFAC and local, state, and federal partners to position the area for long-term and sustainable reuse,” said Cheryl Driscoll, President of CFAC’s parent company Glencore Ltd. 

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The area, also called the Anaconda Aluminum Co. Columbia Falls Reduction Plant Superfund Site, operated from 1955 to 2009. The aluminum smelting process created significant amounts of spent potliner material that was stored in unlined landfills near the former smelter building.

Over time, arsenic, cyanide, and fluoride leached out of potliner material stored in two areas of the site and into the groundwater. Other areas of the site were contaminated with PAHs from the aluminum reduction process. 

To address these issues, CFAC will implement cleanup actions such as low-permeability caps on landfills and the construction of a slurry wall to fully encompass the main source of groundwater contaminants. This slurry wall will prevent further contamination of the groundwater, stop the migration of contaminants toward the Flathead River, and bring seeps along the Flathead River into ecological compliance. CFAC will carry out these actions under EPA and DEQ oversight.  

Cleanup actions were selected by EPA in consultation with DEQ in the ROD, which followed a Proposed Plan released in 2023. Significant community engagement activities, such as a public comment period, public meetings, and the development of materials like newsletters and fact sheets accompanied this Proposed Plan. After the public comment period ended, EPA engaged in significant additional community engagement activities, such as public meetings, the development of fact sheets, and technical assistance support.  

The proposed consent decree was filed with the U.S. District Court for the District of Montana and is subject to a 30-day comment period. The complaint and the proposed consent decree are available on the Department of Justice’s Proposed Consent Decree webpage. 

DEQ is separately required to put the proposed consent decree out for public comment. This will be available on DEQ’s website.  

More information on the site is available on the Anaconda Aluminum Co Columbia Falls Reduction Plant Superfund (also called the CFAC site) site profile webpage.  

EPA’s settlement with Denka Performance Elastomer, LLC resolves its failure to properly manage and handle chloroprene waste at the company’s neoprene manufacturing facility in LaPlace, Louisiana. The site is not currently operational.

Among the alleged Resource Conservation and Recovery Act violations, Denka improperly operated its facility to allow high chloroprene emissions, treated and stored chloroprene waste without a permit, and failed to dispose of it properly.

The excessive and dangerous levels of chloroprene emissions reaching workers within the facility and into the community were the subject of a previous EPA administrative order and Clean Air Act litigation. This settlement resolves the problems and ensures that if the facility returns to operation, it complies with the law.

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“Denka’s mishandling of hazardous chloroprene waste and its many violations of the law exposed workers and the surrounding community to excessive chloroprene and potentially serious health risks,” said Assistant Administrator Jeffrey A. Hall of EPA Office of Enforcement and Compliance Assurance. “Although this facility has suspended operations for business reasons separate from these enforcement actions, this order ensures that if the facility resumes operation, it will be in compliance with the law.”

This action follows a December 20, 2022, settlement agreement with EPA, under which Denka agreed to come into RCRA compliance regarding the treatment, storage, and disposal of “poly kettle strainer waste,” a chloroprene waste generated from the manufacture of neoprene at the La Place facility.

Chloroprene, classified by EPA as a likely carcinogen, is used as an ingredient to create products such as wetsuits, gaskets, hoses, and adhesives. The “poly kettle strainer waste” contributed to emissions of chloroprene during operations that involved the transfer of the waste into an outside, open-air brine pit.

Under the December 2022 settlement, to come into compliance with RCRA, Denka modified its waste management practices and was prohibited from placing “poly kettle strainer waste” into an open brine pit. These actions resulted in a reduction of 1 ton of chloroprene emissions per year at the facility.

EPA also previously sued Denka under Section 303, the Emergency Powers provision, of the Clean Air Act in February 2023. The Trump Administration dismissed that lawsuit, saying it relied on an expansive and improper legal theory.

EPA conducted onsite inspections in April and May of 2022, and again in May 2023, where EPA observed Denka’s waste management practices at the facility. The EPA inspection in May 2023 verified compliance with the December 2022 settlement. The Agency also conducted waste sampling on the “poly kettle strainer waste” that confirmed the waste to be an ignitable hazardous waste.

Other violations identified during these inspections are resolved by EPA’s current settlement agreement with Denka. EPA’s inspections were conducted in partnership with the Louisiana Department of Environmental Quality.

The terms of the current settlement require Denka to certify the clean-out and removal of residual liquid and solid waste in the outside brine pit and its ancillary equipment. The facility is also required to comply with RCRA disposal requirements for the liquid and solid waste generated during waste removal. The agreement includes a requirement that Denka pay a civil penalty of $996,703.

In May 2025, Denka announced a suspension of operations. Currently, no chloroprene inventory is onsite. Should Denka resume operations at any time, the settlement requires the company establish and maintain an inventory of all solid waste streams for proper hazardous waste determinations and update any changes to its permit regarding newly identified waste codes and associated units. Denka will also be required to:

Upgrade the waste handling areas and equipment;
Certify tank integrity;
Store and treat chloroprene-related waste in compliant containers;
Control container waste emissions;
Ensure worker training and the use of personal protective equipment; and
Transport and dispose of chloroprene-related waste in accordance with hazardous waste program requirements.

The Denka Consent Agreement and Final Order is available on EPA’s Denka Performance Elastomer, LLC LaPlace, LA, RCRA Settlement Summary webpage.

For more information, visit EPA’s Resource and Conservation Recovery Act Compliance Monitoring webpage.