Building Public Trust to Reduce Inflow & Infiltration: Lessons from the Milwaukee Metropolitan Sewerage District (MMSD)

Check out the MMSD website for more information on public outreach for these I&I programs

Inflow and infiltration (I&I) can be a major concern for wastewater utilities and their collection systems. I&I is the main reason why basement backups and sewer overflows occur. Addressing I&I is particularly critical in regions like the Great Lakes, where utilities are already experiencing more frequent and intense wet-weather events.  This shifts the focus from cost savings to risk management, as increasing rainfall and groundwater levels increase stress on collection systems and treatment facilities. If left unaddressed, I&I could lead to system overloads, treatment plant failures, and sewer backups—posing serious risks to public health and the environment.

MMSD’s Private Property I&I (PPII) and Pipe Check Programs

Milwaukee Metropolitan Sewerage District (MMSD) operates two wastewater treatment plants with a combined average daily flow of approximately 150 MGD and a maximum wet-weather treatment capacity of 630 MGD. MMSD serves over 1 million people in 29 communities, with some portions of the sewer system more than 130 years old.

MMSD has taken a proactive, risk-based approach to addressing inflow and infiltration (I&I)—particularly by focusing on reducing sources that originate on private property. A significant portion of I&I often originates on private property, where utilities have limited direct control. MMSD’s Private Property Inflow & Infiltration (PPII) Program is designed to address this challenge by working directly with homeowners to identify and reduce sources of clear water entering the sanitary sewer system through two programs. Becky Specht, the Urban Water Program Manager at MMSD, shared important insights with us on MMSD’s Municipal PPII Program. Under the Municipal PPII Program, MMSD works directly with Municipalities in their service area to identify areas of concern and is even able to provide funding to those municipalities for local larger scale projects addressing the sources of I&I identified.

Hannah Johnson, Public Engagement Specialist for MMSD, shared successes with MMSD’s Pipe Check Program, a program focused directly on homeowners that offers financial incentives to reduce a homeowner’s cost of a comprehensive lateral replacement and the disconnection of sources of clear water discharged to the sanitary sewer system. The Pipe Check program connects homeowners with approved contractors, who can guide them through potential options for their situation and manage participation.  Pipe Check financial incentives are paid by MMSD directly to the Pipe Check approved contractor, reducing the remaining balance to the homeowner.

Both representatives emphasize the importance of recognizing that there is no “one size fits all” solution to I&I. “You can’t assume the source of I&I is the same in every area of your community. ” says Specht. “It might involve a multi-layer process to investigate, understand, and rethink what the most impactful solution is for each specific project. Critical to finding the solution, then, is building a relationship with the public. Whether asking homeowners to opt-in to the PPII Program or receiving more reactive customers in the Pipe Check program, building a culture of transparency and trust is the key. Without homeowner participation, there is no PPII program.

Transparency

Specht and Johnson both emphasize their focus on comprehensive transparency at every stage of their work with homeowners and customers. “It’s all about education of the homeowner, which requires 1:1 communication. We lay out the opportunity for them to participate in the Private Property Program, make sure they are on board every step of the way, and thoroughly communicate why we are making the recommendation,” Specht says. Johnson adds that the PPII Program “is all about bringing awareness to the issue, encouraging ownership of the problem, and helping the homeowner understand the full scope of the solution, which often means a far more comprehensive repair to save money in the long term.”

Trust

Transparency leads to trust, and both Johnson and Specht emphasize the importance of establishing trust as a key part of the success of these programs. “We pre-vet our contractors and use that opportunity to build relationships into the Pipe Check Program,” says Johnson. “When they see something’s not working, they come to us instead of waiting to bring it up after the bid is awarded.” Specht and Johnson also emphasize the importance of finding and working with community advocates. Specht encourages utilities to “Figure out who homeowners turn to on a neighborhood level. What community groups are they part of? What are their neighbors telling them? Who do they call with questions? How can we continue to communicate with those people?”

Next Steps

Both Becky Specht and Hannah Johnson recognize that programs like theirs aren’t always feasible or possible in smaller or more under-resourced utilities. However, they encourage PRESERVE members to work with the budget they have to make the most impact possible. “It all comes down to really understanding what your source of I&I is and putting your money towards the correct solution,” encourages Specht. “Take your lessons learned and implement them!”

For more information on MMSD's outreach initiatives, visit their website. And don't forget to review (and share) Moonshot Mission's guidance document on I&I reduction!