Arrowhead, as part of the KEMRON/Arrowhead Joint Venture, completed a sediment remediation project at the Scanlon Reservoir in Carlton County, Minnesota, under the EPA Region 5 Remediation Environmental Services (RES) contract. The reservoir, located within the St. Louis River estuary and designated as part of a Great Lakes Area of Concern, had been impacted by decades of industrial and municipal discharges, resulting in the accumulation of sediments containing bioaccumulative contaminants, including dioxins and furans.

The primary objective was to isolate and contain contaminants by installing a subaqueous cap across 13.5 acres of the reservoir bed. The cap was composed of reactive carbon materials and a carbon-sand blend to reduce the mobility and bioavailability of contaminants. Arrowhead performed detailed pre-construction sediment sampling, bathymetric surveying, and used hydrodynamic modeling to guide the capping strategy. Specialized marine equipment was employed to ensure precision placement of capping materials in the aquatic environment.

Supporting work included clearing and grubbing of upland areas, construction of a haul road, selective structure demolition, and full site restoration. Real-time turbidity monitoring and water quality sampling were conducted throughout the in-water operations to ensure protection of the surrounding environment and compliance with regulatory standards.

This project highlighted Arrowhead’s technical capabilities in sediment remediation and in-water construction, as well as our ability to safely execute environmentally sensitive work under federal oversight.