The most current information on the Milwaukee Estuary AOC can be found on the Wisconsin DNR website.


The Milwaukee Estuary was designated an Area of Concern (AOC) in 1987 because of historical modifications and pollutant loads that contributed toxic contaminants to the AOC and Lake Michigan. Sediments contaminated with PCBs, PAHs and heavy metals contribute to nearly all of the eleven beneficial use impairments within the original boundaries of the AOC. The rivers within the AOC were also historically modified (straightened and dredged) to accommodate large vessel commercial shipping. While Milwaukee still maintains a viable commercial port, some of the river reaches within the estuary are no longer maintained through dredging.

The original boundaries of the AOC included the lower 5 km of the Milwaukee River downstream of North Avenue Dam; the lower 4.8 km of the Menomonee River downstream of 35th Street; the lower 4 km of the Kinnickinnic River downstream of Chase Avenue; the inner and outer harbors; and the nearshore waters of Lake Michigan, bounded by a line extending north from Sheridan Park to the city of Milwaukee’s Linnwood water intake.

In 2008, the boundaries of the AOC were expanded for the purposes of addressing sites that contributed significant loads of contaminated sediments to the estuary. These expanded portions of the AOC are associated with the beneficial use impairments that are directly connected to contaminated sediment.

~Cedar Creek downstream from Bridge Road to confluence with Milwaukee River.   This addition encompasses the entire Cedar Creek Superfund Site, which contributes sediments contaminated with PCB’s to the Milwaukee River.

~Milwaukee River and Lincoln Creek from confluence with Cedar Creek to North Avenue Dam.  This addition includes the portion of the Milwaukee River influenced by contaminated sediments from Lincoln  Creek and Cedar Creek.  This also includes a large deposit of contaminated sediments located upstream from the Estabrook Park Dam.

~  Little Menomonee River from Brown Deer Road to confluence with Menomonee River, and Menomonee River downstream from confluence with Little Menomonee River to 35th Street.  The Little Menomonee River contains the Moss American Superfund Site, which potentially contributes contaminated sediments to the Menomonee River.

Archived Resources

Newsletters (link leaves site)
Built on Water: Milwaukee’s Vital Resource – Lecture Tour
Milwaukee: A City Built on Water (MPTV documentary-link leaves site)
2013 BUI Restoration Report (the current Restoration Report can be found on the Wisconsin DNR website)