The city of Milwaukee has a combined sewer system which means that both the sewage and the street runoff goes into a shared system where it’s treated and then discharged into the lake.

Kim, our Land Stewardship Manager, pointed out that combined systems are better because the oil and other pollutants that run off the streets are removed, whereas, in a non-combined system, these pollutants would travel directly back into our rivers. However, with the combined system, a heavy rain event sometimes causes an overflow and the mixture of rainwater and sewage must be released into Lake Michigan, but this has been drastically reduced since the completion of the deep tunnel. When this mixture is discharged, the brown color we see isn’t poop, it’s actually the lake sediment being stirred up from the amount of water being introduced.

UEC staff visiting the Jonas Island Water Reclamation Facility

There’s an app you can download here Water Drop Alerts which will alert you of heavy rain events so you help to not overload the system by not running the dishwasher or washing machine and by avoiding long showers during this time.

On the tour, we learned that the whole process from flush to finish is about 24 hours. The final results are:

1) Treated water that’s even cleaner than Lake Michigan water 

2) The creation of an environmentally friendly fertilizer by-product called Milorganite.

Thank you to our friends at Veolia for allowing us to go behind the scenes with them. If you’re interested in checking out the facility I recommend Doors Open Milwaukee when they’re open to the public, but get there early because it’s a highly popular destination and they give out free bags of Milorganite!