GIS Maps and Data
Rain Gauge Data
Blue Notes Newsletter
Blue Notes Newsletter Sign-up
What We Do
Managing Water on Your Property
What You Can Do
Become a Fresh Coast Guardian
Home HazMat Collection
Water Drop Alert
What Not to Flush
Construction and CAD Standard Documents and Special Bid Attachments
Events & Outreach
Contract Compliance Login
Government & Business
Community Exchange (Document Repository)
Rules & Regulations
Dentist Offices & Mercury
Private Property I & I
Industrial Waste & Pretreatment
Industrial Honor Role
Total Maximum Daily Loads (TMDL)
2020 Water Quality Initiative
State Of The Art Report
2020 Facilities Plan Reports
2020 Plan - Addendum 1
2020 Plan - Treatment Report
2020 Plan - Conveyance Report
2050 Proposed Facilities Plan
News and Resources
Blue Notes Sign-Up
Education and Outreach
It's important that everyone take steps to reduce the spread of Coronavirus Disease 2019 (COVID-19). Find out more about COVID-19 in Milwaukee County, WI.
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 your home and our system.
Thanks to the deep tunnel and many other improvements, we average 2.4 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% for the 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.