10,000 Gallons of Untreated Wastewater Leak into Lake Michigan

News Summary

An operational error at the South Shore Water Reclamation Facility in Oak Creek led to a release of approximately 10,000 gallons of untreated wastewater into Lake Michigan on September 18, 2025. The spill lasted for about 30 minutes, and while immediate corrective actions were taken, community concerns remain regarding recreational safety. The incident reflects ongoing issues with wastewater management practices, prompting calls for increased transparency and accountability. Cleanup efforts are expected to conclude by September 30, 2025.

Oak Creek, Wisconsin – An employee error at the South Shore Water Reclamation Facility resulted in a leak of approximately 10,000 gallons of untreated wastewater into Lake Michigan on September 18, 2025. The incident occurred at 5:30 p.m. when wastewater overtopped the emergency overflow structure due to an operational mistake, leading to a brief overflow lasting about 30 minutes.

Initially, estimates suggested that the volume released was around 20,000 gallons, but this figure was later revised as half of that volume was recovered and treated. The spill coincided with a staff shift change at the facility, which is believed to have played a role in the oversight that caused the incident. Veolia Water Milwaukee, the contractor for the Milwaukee Metropolitan Sewerage District, operates the facility.

Immediate corrective actions halted further overflow. This included adjusting gates and valves, pumping out the excess wastewater, and cleaning the affected system of remaining sewage. Cleanup and correction efforts are expected to be completed by September 30, 2025. Nonetheless, the report noted a potential risk for human exposure to untreated wastewater through recreational activities in the waterway.

Facility Background and Previous Incidents

The South Shore Water Reclamation Facility processes approximately 104 million gallons of wastewater each day. This incident marks the second untreated wastewater spill linked to Veolia within 2025. A previous incident in March resulted in a similar escape of approximately 10,000 gallons into Lincoln Creek and the Milwaukee River, caused by a mistake where wastewater was discharged into a storm sewer rather than a sanitary sewage system. Earlier, in April 2025, the same facility had to manage about 1,000 gallons of wastewater leakage into Lake Michigan due to a broken pipe.

Regulatory Reporting and Accountability

The incident has been reported to the Wisconsin Department of Natural Resources (DNR) within the required five-day notification period following the leak. Paul Keppler, vice president and general manager at Veolia, indicated that disciplinary action has been taken against the employee responsible for the leak. Additionally, a more comprehensive turnover process is being implemented at the facility to mitigate the risk of such errors in the future.

Impact and Community Response

While the immediate risks have been addressed through cleanup efforts, there remains concern among community members regarding the safety of recreational activities in Lake Michigan. Local officials are monitoring the situation closely and advising the public about potential hazards related to untreated wastewater exposure.

The residents and environmental advocates are urging for increased transparency and accountability in wastewater management practices, especially given the recurrence of such incidents over the past year. As Veolia Water Milwaukee continues to address the issue, they are expected to provide updates regarding system improvements and overall facility operations in hopes of restoring public confidence.

With the completion of cleanup efforts slated for the end of September, ongoing assessments of the facility’s operations will be crucial to ensure the reliability and safety of wastewater management in the future.

Deeper Dive: News & Info About This Topic

• Milwaukee Journal Sentinel: Human Error Caused Wastewater Overflow into Lake Michigan
• Milwaukee Journal Sentinel: About 20,000 Gallons of Untreated Wastewater Leaks into Lake Michigan
• WECT: Over 17,000 Gallons Untreated Wastewater Discharged into Cape Fear River
• Wikipedia: Wastewater
• Encyclopedia Britannica: Wastewater