Milwaukee Estuary Area of Concern (AOC)

The City of Milwaukee is working with Federal, State, and local partners on the clean-up of the Milwaukee Estuary Area of Concern (AOC). The AOC was designated by an international body that includes the US EPA in 1987. The AOC is a result of pollution in our waterways that was caused by historic industrial activities and untreated stormwater runoff. The AOC is regional and includes parts of Ozaukee County, the Milwaukee River, Menomonee River, Kinnickinnic River, and Milwaukee Bay. The main priorities for the cleanup include: removal of contaminated sediment, improving and reducing stormwater runoff, improving water quality for recreation, and improving fish and wildlife habitat. These priorities are reflected in the projects that have been undertaken to ultimately delist the AOC.

Where to Find Information!

Resources, project descriptions, and information about how to participate in AOC activities can be found on the Waterway Restoration Partnership website. The Waterway Restoration Partnership is a group of long-standing, trusted partners in the community who have been working together for years to improve water quality in the area.

AOC Projects in the Grand Trunk Area

Grand Trunk Wetland Habitat Restoration Project

The Grand Trunk Wetland (also known as the Bay View Wetland) is located at 1950 South Marina Drive. It is one of the last remnants of the Milwaukee Estuary's historical network of wetlands.

Planning for the wetland restoration began as a result of recommendations included in the Southeast Side Area Plan which was completed in the 2008. Restoration of the wetland is also identified as a catalytic project in the 2017 Harbor District Water and Land Use Plan. The Fund for Lake Michigan provided the initial funding for restoration planning. The documents that resulted from this process included the Bay View Wetland Master Plan (2014), the Grand Trunk - Bay View Wetland Restoration Data Gap Analysis and Environmental Summary Report (2017) and the Grand Trunk – Bay View Wetland Restoration Engineered Design Feasibility Report (2017).

In 2017, the Wisconsin Department of Natural Resources (WDNR) directed Great Lakes Restoration Initiative (GLRI) funds to complete the wetland restoration design, engineering, and project coordination. Between 2017 and 2021 the Redevelopment Authority of the City of Milwaukee (RACM) and the WDNR led a group of stakeholders who developed a wetland restoration design. The Grand Trunk design fits into the greater habitat restoration efforts within the AOC and will result in improvements for fish and wildlife.

Due to the site's historic uses and the discovery of contamination in the sediment the wetland will need additional remediation. The timeline for the project has been pushed back and the project will be coupled with a larger sediment cleanup project and accomplished through the Great Lakes Legacy Act. The creation of the Dredged Material Management Facility (DMMF) and the South Marina Drive Storm Sewer Cleanup are both a key drivers for determining the timeline of the wetland restoration.

Additional updates on project status will be provided here as they become available.

Wetland Restoration Design (2018)

Historical Land Use Map

South Marina Drive Storm Sewer PCB Cleanup Project

The City completed a sediment assessment at 1950 South Marina Drive in the Grand Trunk Slip (aka Skipper Buds Slip) in September 2018. This assessment identified polychlorinated biphenyls (PCB) at analytical concentrations that exceeded the 50 mg/kg Toxic Substances Control Act (TSCA) threshold. Between 2018 and 2021 the City and Wisconsin Department of Natural Resource (WDNR) completed additional investigations in the Grand Trunk Slip to define the vertical and horizontal extent of the PCB impacts.

The City simultaneously conducted a series of sampling events in a storm sewer located immediately adjacent to South Marina Drive and the Grand Trunk Wetland. PCB contamination above the TSCA threshold was discovered in storm sewer.

A Notification for Hazardous Substance Discharge for PCB impacted sediment in the storm sewer was reported to WDNR on February 2, 2021. WDNR notified the US Environmental Protection Agency (US EPA) of a PCB release and issued a Responsible Party letter to the City on February 15, 2021. The case was assigned a project management and DNR BRRTS Activity No. 02-41-587190 and DNR FID No. 341331430.

A series of meetings and conversations occurred between the City, WDNR, and US EPA to determine the regulatory requirements for investigating the extent of the contamination. The City submitted a Work Plan to the US EPA to delineate the PCB contamination and it was approved on July 22, 2021. The City began implementing the Work Plan in late summer 2021 and completed dye testing, outfall testing, water level monitoring, and sampled areas adjacent to the storm sewer.

Throughout 2022 and 2023 the City worked with private property owners in the area to identify and delineate potential sources of contamination. This work included dye testing, mapping, sampling, and the removal of drums and other hazardous materials. This work is on-going and will continue into 2024.