Over the last several decades, Woodard & Curran has been involved with various aspects of the remediation and reclamation of the Anaconda Co. Smelter Superfund Site in Anaconda, Montana. Added to the national priorities list (NPL) in 1983, the area historically played host to metals milling and smelting activities. Soil, groundwater, and surface water are impacted with elevated concentrations of arsenic, copper, cadmium, lead, and zinc. A confidential client engaged Woodard & Curran to evaluate remedial alternatives for over 30,000 acres of smelter-impacted soils at the site and develop designs to treat impacted soils and limit transport to surface and groundwater receptors.
Woodard & Curran designed, coordinated, and managed the implementation of numerous investigation projects for the collection of necessary data to develop remedial alternatives and designs. The information collected included media-specific data, equipment feasibility evaluations, soil amendment requirements, and vegetation-related data. As part of this large-scale remediation project, the project team also designed a GIS database to manage the tremendous volume of data accumulated.
The project team developed standard operating procedures and quality management protocols used by multiple entities conducting sampling throughout the NPL site. Building on these procedures and protocols, Woodard & Curran staff have negotiated investigation and remedial action confirmation sampling approaches utilizing state-of-the art statistical modeling to achieve high confidence in defensible data acquisition used in the investigation of residential areas in and around Anaconda that were potentially impacted by historic smelting/mining activities.
Woodard & Curran personnel have developed strict, Quality Assurance and Quality Control criteria, including developing detailed Data Quality Objectives that follow the latest federal guidelines. This ensures a high degree of efficiency while minimizing the potential sources of error in data acquisition and identifying environmental liabilities associated with the past use of the site. These criteria are applied to data collected on site and generated through laboratory testing.
The project team was tasked with developing alternatives and ultimately full remedial designs for 17 impacted units throughout the project area. Alternative evaluation and designs primarily involve soil treatment or amelioration in response to both human health and vegetation phytotoxicity soil risk for contaminants of concern.
The remedial designs address specific performance criteria negotiated with state and federal regulatory agencies and meet all applicable environmental regulations. In addition, Woodard & Curran has performed remedial construction oversight for several of the EPA-approved designs.
A primary component of the reclamation in this area is to re-establish a diverse vegetation community to minimize erosion, reduce contaminant transport, and to encourage establishment of wildlife habitat. Woodard & Curran has worked closely with project partners to plant hundreds of thousands of trees and shrubs. As revegetation efforts continue, the total estimated quantity of trees and shrubs to be planted upon completion is nearly 1 million.
The species of trees and shrubs depend on multiple factors including existing vegetation, topography, soil type, and aspect. Several of the species selected include Silver Sagebrush, Mountain Mahogany, Rubber Rabbitbrush, Limber Pine, Aspen, Ponderosa Pine, Woods Ros, Buffaloberry, and Snowberry. Areas that were formerly forested and have surrounding forested areas focused on a planting strategy consisting of primarily tree species. In locations that were originally grasslands or shrublands, planting plans emphasize shrubs. Trees and shrubs are grown in Montana nurseries using seed obtained from local, native stock and delivered to the site under refrigerated conditions.
In addition to the remedial designs and revegetation, Woodard & Curran personnel have supported the development of site media-specific management plans for performance and compliance monitoring to ensure the long-term integrity of the reclamation efforts under various future land use scenarios or development. In addition to monitoring ongoing success of remedial measures, we have conducted annual vegetation and erosion monitoring at the site since 2004.