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Superior Sediment Remediation Projects

Public Comments on the Superior Slips Sediment Remediation Project Accepted Until June 7, 2024

Public Meeting Presentation on Superior Slips Remediation Options

Watch the video recording of the public meeting or see the public meeting presentation slides to learn about contamination in the Superior Slips, the alternatives for cleaning up contaminated sediment, how they were evaluated, and the project recommendations.

Your feedback is important to us, and we want to hear from you. Comments on the cleanup options for the Superior Slips Sediment Remediation Project will be accepted until June 7, 2024.

Please complete this questionnaire to share your comments. Alternatively, comments may also be emailed to DNRRRSuperiorSlips@Wisconsin.gov.

Superior Slips

General Mills Shipping Slip
General Mills Shipping Slip

The Superior Slips Sediment Remediation Project is one of several projects to clean up and restore the St. Louis River Area of Concern. This project focuses on contaminated sediment in three industrial shipping slips at the Port of Superior: General Mills Slip, Oil Barge Dock Slip and Tower Avenue Slip.

Over a century of heavy industrial activities next to the St. Louis River have led to environmental degradation of sediment in areas of the harbor. Sediment in these slips is contaminated with metals, mercury, organotin, polycyclic aromatic hydrocarbons, and other compounds that are targeted for cleanup by 2026 as part of the overall effort to remove the St. Louis River from the list of most polluted sites on the Great Lakes.

As of March 2024, the activity status for this project includes:

  • Investigating and characterizing the nature and extent of sediment contamination - completed in 2023.
  • Developing and evaluating alternatives for remediating sediment contamination - completed in 2023.
  • Developing a recommended alternative to address the contamination - accepting public comments until June 7, 2024.

Project Schedule and Opportunities to Get Involved

The Superior Slips Sediment Remediation Feasibility Study began in June 2022 and is projected to be completed in spring 2024 with a set of recommendations for actions to clean up sediment in the slips.

Based on its consultant’s evaluation, the DNR is recommending options for removing contaminated sediment in three large slips in the Port of Superior. More details are available in the remedial action options report (RAOR) for each slip in the Technical Reports section below.

The DNR plans to seek additional project partners and perform limited pre-design activities before starting remedial design. The design of the chosen remedy is anticipated to occur in 2024 - 2025, and the work to clean up the polluted sediment is expected to take place in 2026 and beyond.

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Technical Reports

The following reports provide details about sediment contamination evaluations and other project findings.

Links to Remedial Action Options Reports

Report Name BRRTS Number
Oil Barge Doc Slip, Remedial Action Options Report, AECOM 2023 [PDF, 78 MB] 11-16-591466
General Mills Slip, Remedial Action Options, AECOM 2023 [PDF, 51 MB] 11-16-591466
Tower Avenue Slip, Remedial Action Options Report, AECOM 2023 [PDF, 58 MB] 11-16-591466

Additional technical reports are also available from the DNR Bureau of Remediation & Redevelopment Tracking System (BRRTS) on the Web (BOTW) at https://dnr.wisconsin.gov/topic/Brownfields/botw.html. These reports can be obtained from BOTW by searching for the BRRTS activity number 11-16-591466 or Activity or Location Name = Superior Slips.  

Site Maps

St. Louis River AOC Remediation Sites - Sept. 2022
St. Louis River AOC Remediation Sites - Sept. 2022
Map of Superior Slips Project Locations
Map of Superior Slips Project Locations