Milwaukee’s Sewer System Is a Success Story

Inside the Deep Tunnel. Photo courtesy of MMSD.

Public infrastructure is easy to take for granted when it works. Most of us never think about what happens after we flush a toilet, drain a sink, or watch stormwater disappear down a grate. Yet beneath our feet in Milwaukee lies one of the most complex and important public works systems in Wisconsin and the country, a system that protects public health, safeguards Lake Michigan, and serves more than one million people across Milwaukee County and the surrounding region.

As former City of Milwaukee Department of Public Works Commissioners, we believe it is important to provide perspective amid recent criticism of how the regional wastewater system is managed.

The first thing to understand is the sheer scale of the challenge. MMSD serves 28 communities across a service area of more than 400 square miles. The regional system includes hundreds of miles of large interceptor sewers connected to thousands of miles of municipal sewer lines stretching beneath virtually every street in Milwaukee County and beyond. This is an engineering network of extraordinary size and complexity, operating 24 hours a day, 365 days a year.

No system of this scale is perfect. There will always be opportunities for improvement, modernization, and investment. Responsible public servants should welcome those conversations. But it is equally important to recognize how far Milwaukee has come.

Twenty-five years ago, sewer overflows into local waterways were far more common. Since the completion of the Deep Tunnel system and decades of strategic investments, the region has captured and cleaned more than 98 percent of the stormwater and wastewater entering the system, well above the national benchmark for communities with combined sewer systems. The Deep Tunnel alone has prevented billions of gallons of pollution from reaching Lake Michigan.

The progress extends beyond pipes and treatment plants. For decades, MMSD has worked collaboratively with municipal governments, the Wisconsin Department of Natural Resources, community organizations, and private-sector partners to implement innovative green infrastructure projects. Rain gardens, bioswales, green medians, floodplain restoration, and strategic redevelopment projects have all helped reduce the amount of stormwater entering the sewer system in the first place. Major initiatives associated with projects such as the Marquette Interchange reconstruction demonstrated what can happen when multiple partners work together toward a common goal.

Critics point to recent major flooding events as evidence of failure. But we should be honest about what any sewer system can realistically accomplish. The historic storms of 2010 and several recent extreme rain events brought rainfall totals that exceeded what engineers could reasonably design for decades ago. Across the country, communities are grappling with increasingly intense weather events that challenge even the most advanced infrastructure systems.

That does not mean we stop striving to improve. It means we continue investing, planning, and adapting.

What gives us confidence is not a claim that the system is flawless. It is that the people responsible for managing it have consistently demonstrated a commitment to continuous improvement, transparency, and collaboration. The relationship between MMSD, local municipalities, regulators, and community stakeholders has been one of the region’s strengths for many years.

Milwaukee’s wastewater system is one of the largest public infrastructure networks in the country. Maintaining it is difficult work. Improving it is even harder. But after decades of service and firsthand experience with the district’s operations, we can say this with confidence: thanks to Kevin Shafer, the MMSD team, and the system operator, the system is stronger today than it was 20 years ago, and the dedicated professionals responsible for protecting it deserve recognition for the work they do every day.

Jim Kaminski served as Milwaukee’s Commissioner of Public Works from 1996 – 2004. Jeff Mantes succeeded him and served from 2004 – 2011.