Two Duluth Harbor Slips’ cleanups open for environmental review, comment

Contact: Anne Perry Moore, 218-302-6605

Making environmental progress one slip at a time, the Minnesota Pollution Control Agency (MPCA) announced two more Duluth harbor slips have proposed cleanup plans available for comment through April 4, 2018.

On the heels of the recently-proposed Minnesota Slip cleanup, Slips C and 3 are also home to contaminated sediments from a century of marine- and shipping-related activities. They are currently used as commercial and recreational boat docking areas.

The nearly $4.5 million in combined proposals will place clean material, dredged from the Duluth/Superior harbor, on top the existing contaminated sediments. This newly created “cap” will be beneficial to sediment-dwelling and aquatic creatures, as well as the fish community, while effectively isolating the contaminants from possible release to the harbor, the St. Louis River and Lake Superior.

Work is expected to begin in both slips in September 2018 and last through December 2018.

Currently, the slips’ contaminated sediments average approximately 2.5 feet to 6 feet thick and an estimated combined volume of 116,000 cubic yards. Contaminants include polyaromatic hydrocarbons, lead, polychlorinated biphenyls, mercury, cadmium, copper, nickel, dioxins, and zinc.

Working slips were the heart of Duluth’s waterfront and helped drive the port to world-class status. Prior to current environmental regulations, Slips C and 3 were two of dozens of unintended dumping sites for waste runoff and pipe discharges. Since then, laws and technology have evolved so scientists can not only identify and measure contaminants and understand their effects on aquatic creatures, but also select and implement the most efficient and cost-effective remedies possible to remove or neutralize the contaminants’ compounded effects.

These proposed cleanups will not only help improve the slips’ water quality but the larger St. Louis River watershed as well. The slips were identified in 2015 as one of 10 sites in the St. Louis River Area of Concern in need of cleanup. Cleaning up these slips will help bring the SLRAOC one step closer to taking it off the binational list of most-contaminated ports on the Great Lakes.

Adjacent landowners have been actively involved in the remedy selection process and are aware of the impending potential 24-hour-a-day construction schedule.

For the projects to move forward, state and federal permits and authorizations will be required. Funding is secured as a 35/65 match between state bonding dollars and the U.S. Environmental Protection Agency’s Great Lake’s Legacy Act.

State agencies use an Environmental Assessment Worksheet to help decide whether a project requires a more extensive Environmental Impact Statement. The worksheet covers site location details, nearby resources and other elements, including wells, soil types, water use, manure management, air and odor emissions, and traffic.

These projects’ worksheets are available on the MPCA's Environmental Assessment Worksheet webpage. They are also available by calling Patrice Jensen at 651-757-2465. Written comments specifying the cleanup site may be sent by email to her at, or mailed to her attention at the MPCA, 520 Lafayette Road N., St. Paul, MN 55155. All comments must be received by 4:30 p.m. on April 4, 2018.

To learn more about this process, visit Environmental Review webpage.