Basin H Sewers PCB Cleanup

The Milwaukee Metropolitan Sewerage District (MMSD) partnered with the United States Environmental Protection Agency (USEPA) to clean sewers located west of the Milwaukee River along North Humboldt Boulevard between East Capitol Drive and East Locust Street—an area known as “Basin H” in 2022-2023.

A 2008 investigation identified the Milwaukee Die Cast Company, located at 4132 North Holton Street in the City of Milwaukee, as the primary source of polychlorinated biphenyls (PCBs) coating sewers in this area. PCBs are legacy chemicals that were banned in 1978 and must be removed to protect water quality and prevent future environmental impacts.

The USEPA removed PCB contamination at the business site. MMSD then completed the removal and safe disposal of the remaining PCB contamination within the sewer system.

How the Cleanup Worked

A qualified contractor used powerful vacuum equipment and specially outfitted trucks with sealed liquid containers to clean the sewers through manholes located along North Humboldt Boulevard and in Kern and Pleasant Valley Parks. Precautions were taken to secure work sites and prevent contaminated sediment from moving downstream.

The project followed a USEPA-approved remediation plan, which included:

Cleaning the sewers and removing contaminated sediment
Drying the removed sediment and capturing the water
Testing sediment for PCBs and transporting it to an approved disposal site
Treating wastewater to remove PCBs
Testing treated water before returning it to the sewer system
Inspecting the sewers with cameras to confirm sediment removal
Conducting pre- and post-cleaning sampling of sewers and surrounding areas

Project Map

Typical vacuum equipment used to remove PCB’s from sewers.
Trucks with sealed liquid container.

Why it Matters

This project removed PCB contamination from the sewer system before it could impact the Milwaukee River and Lake Michigan.

PCBs do not break down easily and can build up in fish and wildlife over time. Cleaning them out of the system helps protect water quality, aquatic life, and people who rely on these waterways.