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The Milwaukee Metropolitan Sewerage District (MMSD) cleans billions of gallons of wastewater every year, safeguarding natural resources and protecting public health for 28 communities in southeastern Wisconsin.
We treat a range of wastewater sources from industrial to surface runoff and whatever water you send down the drain at home, work, school, or church. Often people think you can flush anything down the toilet or drain and that is not true. Learn what not to flush to protect our water, your home, and our systems.
Our two water reclamation facilities, Jones Island and South Shore, can efficiently clean about 150 million gallons of water on a dry day and 630 million gallons of water a day when it is raining.
Thanks to the deep tunnel and many other improvements, we average 2.3 overflows per year (down from 50-60) and have captured and cleaned 98.4% of all the water that's entered the regional sewer system since 1994. The goal nationally is to capture and clean 85% of water for more than 700 cities with systems like ours. We continue to strive for zero overflows by investing in our treatment plants, sewers and implementing green infrastructure in our region to help manage water where it falls.
Learn the four stages of the wastewater treatment process.
Learn why we need deep tunnels, how they work, and where they are in our system.
Why do overflows happen? MMSD addresses the issue.
How many miles of laterals, city sanitary sewers, regional sewers and Deep Tunnels are there anyway?
Learn how you can tour one of our wastewater treatment facilities or our laboratory.
Federal and Wisconsin law requires the MMSD to have a discharge permit. Learn what the permit includes, and how it protects public health and the environment.