Columbia Falls Aluminum Co. has developed a draft work plan to address contamination at its former aluminum processing facility in Columbia Falls.

Last year, CFAC, which is owned by commodities trading conglomerate Glencore, hired environmental consulting firm Roux Associates Inc. to develop the remediation plan.

The sprawling industrial site northeast of Columbia Falls is contaminated by several toxic substances, including fluoride, cyanide, arsenic and lead.

The remediation plan calls for Roux to conduct field investigations next year, with a summary report due in early 2017. The assessment process is scheduled to take 4 1/2 years.

According to a news release, the company approached the federal Environmental Protection Agency in 2014 to enter into an agreement to provide regulatory oversight of the plan, as well as opportunities for agency review and comments during the plan’s implementation. The company said in the release it would modify the draft plan if it reaches an agreement with the EPA.

Officials from CFAC had expressed interest in working with the state to develop a cleanup agreement that would be subject to oversight from the Montana Division of Environmental Quality. However, the company broke off talks with the state agency late last year and on March 24 the federal Environmental Protection Agency proposed listing the site on the National Priorities List, also known as Superfund.

Company officials and others have expressed opposition to Superfund designation, maintaining that it would unnecessarily delay cleanup.

But the Environmental Protection Agency, along with some community leaders in Columbia Falls, argued that the company would not be held to the same standard for remedial work without the federal oversight that comes with Superfund designation. The public comment period for the Superfund proposal ended June 2.

Another contractor hired by the company, Oregon-based Calbag Resources, has begun preliminary work on the property, including demolition of some of the older buildings at the site.

CFAC is asking the public, regulators and other interested parties to review and comment on the document. It can be found at www.rouxinc.com/CFAC-Draft-RI-FS-Work-Plan-Available-for-Public-Comment.

Comments can be made online, emailed to CFAC-Comments@rouxinc.com or mailed to CFAC RI/FS Comments, Roux Associates, c/o Columbia Falls Aluminum Co., 2000 Aluminum Drive, Columbia Falls MT 59912.

The company held a public advisory panel meeting Thursday.

Working with public relations firm Ann Green Communications, CFAC is soliciting input on the shuttered plant’s future, including cleanup plans. The firm selected 27 people, including company officials, local elected representatives, business leaders and citizens for the panel, which officials said is intended to improve dialogue between the company and the community.

Reporter Samuel Wilson can be reached at 758-4407 or by email at swilson@dailyinterlake.com.