Remediating the Anaconda Superfund Site

In the 1980s, the Environmental Protection Agency designated the former Anaconda Co. Smelter site and surrounding areas as Superfund sites—among the nation’s largest. Historic milling and smelting activities produced wastes that impacted the soil, groundwater, and surface water with elevated concentrations of arsenic, copper, cadmium, lead, and zinc. A confidential client engaged TREC, a Woodard & Curran company, to evaluate remedial alternatives for over 30,000 acres of smelter-impacted soils at the site and develop remedial designs to treat impacted soils and limit transport to surface and groundwater receptors.

Details of the alternative evaluation and remedial designs

The alternative evaluation and design considers soil treatment or otherwise ameliorating impacted soils (removal, capping, in-situ treatment, vegetation improvement, steep slope remediation) in response to both human health action levels (primarily arsenic and lead) and vegetation phyto-toxicity soil effects concentrations for contaminants of concern (arsenic, cadmium, copper, lead, and zinc). TREC designed, coordinated, and managed the implementation of numerous investigation projects for the collection of necessary data to develop the detailed remedial designs. Information collected included media-specific data, equipment feasibility evaluations and soil amendment requirements, and vegetation-related data. As part of this large-scale remediation project, the project team also designed a GIS database system to manage the efficient application of the tremendous volume of data obtained for the design efforts.

The remedial designs address specific performance criteria negotiated with state and federal regulatory agencies and meet all applicable environmental regulations. In addition, TREC has performed remedial construction oversight for several of the EPA-approved designs. 

Site management plans protect human health and the environment

TREC is in the process of creating or assisting in the development of site media-specific (soils/vegetation, surface water, groundwater, and institutional controls) management plans for performance and compliance monitoring. The firm’s planning documents describe the coordination and integration of a County Development Permit System and other institutional controls that will confirm the long-term integrity and protectiveness of the reclamation efforts under various future land-use scenarios and/or development.


Confidential Client
Anaconda, MT


Senior Project Manager