Milwaukee Metropolitan Sewerage District


The Milwaukee Metropolitan Sewerage District is a regional government agency that provides water reclamation and flood management services for about 1.1 million people in 28 communities in the Greater Milwaukee Area. A recipient of the U.S. Water Prize and many other awards, the District has a , since 1994, for capturing and cleaning wastewater from 28 communities in a area. The national goal is 85% of all the rain and wastewater that enters their sewer systems.
With headquarters and a central laboratory along the Menomonee River near downtown Milwaukee, it has two wastewater treatment plants which are located at Jones Island in Milwaukee and at the South Shore in Oak Creek. These facilities were operated by United Water under a 10-year agreement ending March 1, 2008. Veolia Water is the current operator.
"The world’s first large scale wastewater treatment plant was constructed on Jones Island, near the shore of Lake
Michigan." The primary wastewater treatment plant at Jones Island was one of the first of its kind when the original activated sludge plant was constructed in 1925. MMSD was the first to market biosolids created through this process as a fertilizer under the name "Milorganite." The Jones Island Plant was among the first sewage treatment plants in the United States to succeed in using the activated sludge treatment process. "It was the first treatment facility to economically dispose of the recovered sludge by producing an organic fertilizer." In the early 1980s the plant needed extensive reworking, "this does not detract from its historic significance as a pioneering facility in the field of pollution control technology." It had the largest capacity of any plant in the world when constructed. The 1925 plant has been designated as a Historic Civil Engineering Landmark by the American Society of Civil Engineers. MMSD has maintained an inline storage system based on tunnels to store and convey wet weather flows, including combined sewage, since 1994. The ISS tunnels have a total capacity of 400 MG and a combined length of over 20 miles. Since 1994, the ISS tunnels have prevented more than 37 BG of CSOs and SSOs from entering area waterways, including Lake Michigan. Between 1994 and 2000, CSOs decreased from 40-60 events per year to an average of 2.5 events per year.

MMSD Initiatives

Flood Management

Flooding and erosion of the watersheds in the greater Milwaukee area threaten public health and private property. Watersheds boundaries do not necessarily follow municipal boundaries, reducing the risk of flooding requires looking at the watershed as a whole, including the complete river system and its tributaries. The Milwaukee Metropolitan Sewerage District has discretionary authority to maintain the watersheds in the Greater Milwaukee Area and authority to reduce the risk of flooding is in Wis. Stats., sec. 200.31. In the past, work has included: rehabilitation and removal of concrete, removal of sediment and flow-impeding objects, and widening floodplains for flood management purposes.

Fresh Coat Guardians Resource Center - Green Infrastructure

The Fresh Coast Resource Center helps southeastern Wisconsin improve the health of Lake Michigan through smart use of The FCRC assists the community by providing the inspiration, education, and tools needed to create successful green infrastructure projects.
In 2017, MMSD opened the FCRC to empower people, homeowners, businesses, nonprofits, and government to take an active role in protecting our most precious natural resource: water.  By helping the community to protect our rivers and Lake Michigan, we work to achieve our goal of capturing the first 0.5 inch of rainfall in our service area. By capturing the first 0.5 inch of rain, 740 million gallons of water will stay out of our sewers, helping to prevent sewer overflows and reducing runoff pollution.

Combined Sewer Overflows

Diverting combined sewer to waterways is an emergency measure to prevent sewage backups into basements when wastewater treatment facilities reach capacity. MMSD follows the 2014 State of Wisconsin Department of Natural Resources Discharge Permit for Combined Sewer Overflows are sewers that are designed to collect rainwater runoff, domestic sewage, and industrial wastewater in the same pipe. When a CSO happens,they post it on their website and have 5 days to report it to the DNR. , bacteria from CSO's only survive for up to 10 days due to the frigid temperatures of Lake Michigan. Combined sewer overflows are 90 to 95% stormwater and groundwater.
MMSD's combined sewer overflows are smaller than those of other cities on the Great Lakes, including Cleveland's and Detroit's, and are similar to that of the smaller city of Grand Rapids. Year-to-year combined sewer overflows vary depending on local rainfall but as a recent example in 2014 MMSD combined sewer overflows totaled 342 million gallons, meaning that 99.5% of the total flow through the municipal sewer system was treated. MMSD’s permit requires that Controlled Sewer Overflows be limited to no more than six overflows per year, consistent with the presumption approach in the CSO Control Policy.
Separating the sanitary and storm sewers would decrease the amount of water captured and treated, however the amount of pollutants going into our rivers and Lake Michigan would increase. In urban areas with lots of impervious surfaces, there is little opportunity for stormwater to be absorbed into green areas. Resulting in run off with a high degree of pollutants that would further erode water quality.

Deep Tunnel

"Since 1994, a more than 26-mile- long tunnel has been keeping Milwaukee's sewage from spilling into Lake Michigan. This deep water tunnel—a holding tank on steroids—comprises two legs roughly 300 feet belowground that can hold nearly 500 million gallons of sewage and storm water during a downpour. And for the last 14 years it has kept 74 billion gallons of wastewater out of Lake Michigan, according to Bill Graffin, a spokesman for the Milwaukee Metropolitan Sewerage District." - David Biello, Scientific American.
The Deep Tunnel has prevented more than 125 billion gallons of pollution from getting into Lake Michigan. Thanks to the tunnel and many other improvements, MMSD has captured and cleaned 98.4% of all the stormwater and wastewater 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.