Another checkmark has been added in the long process of cleaning up and capping contaminants in the Twin Ports harbor with the completion of a sediment cleanup project in the Azcon Duluth Seaway Port Authority Slip.
The U.S. Army Corps of Engineers headed the recently completed project that removed 850 cubic yards of contaminated sediment and capped another 55,000 cubic yards with clean dredge material taken during maintenance of the port’s shipping channels.
The $2 million project is one of dozens on the list to clean up the St. Louis River Area of Concern in the Twin Ports, a legacy of pollution and environmental degradation left behind by a century of industrialization around the harbor.
The still-active docking slip site had high levels of heavy metals and chemicals, including dioxins/furans and polycyclic aromatic hydrocarbons (pollutants commonly known as PAHs).
The Azcon Slip had a history of manufacturing and commercial shipping of steel, appliances and heavy machinery, as well as logging and shipbuilding. Before modern-day environmental regulations, common practices led to a buildup of contamination in the sediment. This resulted in damage to the underwater habitat and negative impacts to the aquatic food chain for fish.
Money for the project came from the federal Great Lakes Restoration Initiative and state funds through the Minnesota Pollution Control Agency.
“By beneficially reusing the dredged material from the navigation channel, the team was able to achieve remedial objectives, limit waste generation and decrease the environmental impact,” said Amanda Meyer, project manager, U.S. Army Corps of Engineers, Detroit District.
The 6.4-acre Azcon Slip is located on Rice's Point off Garfield Avenue near the Port Authority headquarters.
Three additional harbor slip sediment remediation projects — Minnesota Slip, Slip 3 and Slip C — were completed in 2018.