Innovative design of dredged material management facility along Milwaukee Harbor

The Milwaukee Estuary has long been designated a USEPA Great Lakes Area of Concern (AOC) due to legacy contamination in river and harbor sediments that poses ongoing risks to water quality, aquatic ecosystems, and community health. As part of continued efforts to have the AOC delisted and mitigate risks to surrounding communities, the City of Milwaukee, including Port Milwaukee, and the Milwaukee Metropolitan Sewerage District (MMSD), the Wisconsin Department of Natural Resources (DNR), and other key stakeholders, have led development of a dredged material management facility (DMMF) along the Milwaukee Harbor waterfront. Once completed, the DMMF will provide a secure, long-term solution for the containment and management of dredged materials generated from remediation and maintenance activities across the Milwaukee estuary.

Ramboll partnered with the client, MMSD, and other key AOC stakeholders to provide comprehensive design services for the DMMF across the project lifecycle, including alternatives evaluation, detailed engineering design, permitting, bid support, and continued engineering services during construction. The multidisciplinary scope included structural design, site grading, stormwater design, dredging and sediment analysis, geotechnical evaluations, and preparation of construction documents and specifications.

A holistic approach to safeguard water quality, wildlife, and the community

Ramboll’s innovative design included the use of a cutoff wall to provide management of an inward hydraulic gradient within the facility across various operation conditions. Due to the impacted characteristics of the dredged material being placed in the facility, there is a strong desire among AOC stakeholders and the greater Milwaukee community to ensure a robust and long-term containment of pollutants within the facility and protection of the Lake Michigan resource. The designed water management system allows for a relatively simple approach where water levels within the DMMF relative to Lake Michigan can be monitored, ensuring protective inward gradient is maintained.

The project also required navigating complex stakeholder and regulatory processes, including multiple alternatives evaluations during preliminary design, to address capacity and containment considerations. These evaluations resulted in significant design refinements, which Ramboll successfully implemented while maintaining the project’s compressed schedule and supporting timely permitting. Collaborative engagement with agencies and the community was instrumental in advancing the project and ensuring alignment with environmental protection goals.

Through Ramboll’s integrated approach, we delivered a cost-effective, compliant, and durable solution for long-term sediment management that supports ongoing dredging operations and broader restoration efforts. By combining robust containment systems with practical water management controls, the DMMF reduces long-term operational risks while meeting stringent regulatory requirements.

Continued movement towards delisting

The DMMF, as designed by Ramboll, will be instrumental in restoring several Beneficial Use Impairments (BUIs) identified within the Milwaukee AOC. The remediation of legacy contaminated sediments will address BUIs related to restrictions on fish and wildlife consumption, degradation of benthos, and restrictions on dredging activities. And by providing secure containment and long-term management of dredged materials, the facility also contributes to improved water quality and aquatic ecosystem protection, thus addressing BUIs related to the degradation of fish and wildlife populations as well as loss of fish and wildlife habitat.

Ramboll continues to support, MMSD, Michaels Construction, and other key project stakeholders throughout finalization of the facility, which is slated to finish in fall 2026.