Milwaukee Estuary AOC Dredged Material Management Facility

Background

On behalf of WEC Business Services, Foth developed a design for a Dredged Material Management Facility (DMMF) for permanent placement of dredged material from within the Milwaukee Estuary Area of Concern (AOC). The DMMF is located to the north of and adjacent to the existing Milwaukee Dredged Material Disposal Facility owned by Port Milwaukee and operated by the U.S. Army Corps of Engineers (USACE), and is designed to manage 1,900,000 cubic yards of impacted dredged material. We Energies was partially supported by a Harbor Assistance Program Grant which Foth assisted in preparing to design the DMMF.

Approach

The scope of the project consists of the design of 3,250 feet of cellular cofferdam structures that enclose a portion of the Lake Michigan shoreline for the management of dredged material within the Port Milwaukee Lake Bed Grant and providing the Port with expanded facilities; and provides a rubble mound tie-back to the existing USACE rubble mound structure.

Foth has facilitated extensive coordination with the regulatory community and key stakeholders. The Wisconsin Department of Natural Resources, Port Milwaukee, the City of Milwaukee, and We Energies (among others) are Non-Federal Sponsors that consider the DMMF to be an important component of a comprehensive contaminated sediment remedy in the AOC under the Great Lakes Legacy Act.

A Design Technical Work Group (DTWG) was formed by the stakeholders to work together in a collaborative, efficient, and expedient manner to remediate contaminated sediment in accordance with Wisconsin Administrative Code Chapters 292 and NR 700-799, and to meet the goals of addressing the Beneficial Use Impairments related to the contaminated sediment. The DTWG met during the development of the design to discuss:

• Consistency with local, state and federal laws
• Water quality certification
• Wisconsin Pollutant Discharge Elimination System (WPDES) permitting
• Geotechnical data
• Design elements
• Scoping and performing pre-design investigations
• Engineering calculations
• Analysis of disposal alternatives
• Public outreach

Results

Management of the dredged material is key to achieving the goals of the AOC by remediating contaminated sediments that will help remove Beneficial Use Impairments and eventually lead to the delisting of the AOC. The new facility will not only provide storage for environmentally impacted sediments, but may also provide additional public access use opportunities along this portion of the Lake Michigan shoreline.