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Wastewater Management in Milwaukee, Wisconsin

Overview of Great Lakes Wastewater Management
The Great Lakes Watershed
History of U.S. Wastewater Management
Risks and Problems
Milwaukee, WI
Chicago, IL
Detroit, MI
Citizen Groups
Rehabilitation and Action Plan

Milwaukee Metropolitan Sewerage District

Friends of Milwaukee's Rivers

            Milwaukee, located on the western edge of Lake Michigan, is a notorious case study for wastewater management. This is due to two factors: first, the outbreak of cryptosporidiosis in 1993 that sickened hundreds of thousands and killed up to 100 people, an event which also put the health risks of wastewater mismanagement firmly into the psyche of the American public. The second factor is the sharp reduction in combined sewer overflows the city saw in the year following this outbreak upon completion of the Deep Tunnel project, a $3 billion project which was expected to virtually eliminate dumping (MMSD). The city of Milwaukee became a leader in reduction of number of CSOs, from 50-80 overflow events per year before construction of the Deep Tunnel down to an average of 2.5 after construction (MMSD).

            Just before completion of the Deep Tunnel project, Milwaukee made water contamination history when the city's drinking water became contaminated with Cryptosporidium, a parasite that passed through the filtration system of the city's water treatment plants. At least 400,000 residents and visitors of Milwaukee became very sick, and about 100 people died from the illness. Cryptosporidium levels have been proven to be significantly higher after sewer overflows, whether in the form of CSOs or SSOs (WI-DNR). Milwaukee's practice of dumping sewage into Lake Michigan and then using the lake as its primary drinking water source is an obvious cause of this outbreak. Nonetheless, the Milwaukee Metropolitan Sewerage District denies any correlation between sewer overflows and the cryptosporidium outbreak. Citizens of Milwaukee and the surrounding communities, however, know the truth. They have seen the evidence of these overflows and the warning signs posted on their beaches whenever an overflow even occurs.

            The Milwaukee Metropolitan Sewerage District (MMSD) is responsible for the city’s sewerage projects from wastewater treatment to flood management. The MMSD is “a regional government agency providing…services for 28 communities” for a total of “1.1 million people in a 420 square mile service area” (MMSD). The MMSD also has other responsibilities, such as doing water quality research, household hazardous waste collection, mercury collection, and industrial waste monitoring (MMSD). Their stated mission is “to cost-effectively protect public health and the environment, prevent pollution and enhance the quality of area waterways” (MMSD). These are, and should be, the basic goals of any sewerage district authority. It is a big job in the industrial metropolis of Milwaukee.

            The MMSD owns and operates two wastewater treatment facilities in Milwaukee: The Jones Island treatment plant and the South Shore treatment plant. These two plants manage all of the wastewater from the 420 square mile service area of the MMSD (MMSD). At the Jones Island plant, biosolids (or solid sewage wastes) are converted into an organic fertilizer called “Milorganite” (MMSD). This is an effective way to reuse the otherwise useless waste, as well as being a healthy way to reintroduce sewage wastes into the environment. The South Shore plant, on the other hand, uses its biosolids to create methane gas, which is in turn used to produce electricity to power the plant (MMSD). Both treatment plants in Milwaukee are utilizing innovative methods to reuse biosolid waste and turn it into something productive and necessary. For the most part, the two plants are sufficient for handling the city’s wastewater treatment needs: “On a dry day, the Milwaukee Metropolitan Sewerage District's two wastewater treatment plants combined will clean about 200 million gallons of wastewater. When it rains, the volume of water that pours into the sewer system can reach five, six, seven times that dry day amount or even more for big storms” (MMSD). It is these rainy days that set off sewer overflows in the city, since the combined maximum capacity of the two treatment plants is only 600 million gallons per day (MMSD).

Dealing with Sewer Overflows:

            Milwaukee has been notorious for its sewer overflows, both CSOs and SSOs, especially before the year 1994 when a tunnel system was constructed to minimize overflows. Prior to implementation of the Deep Tunnel Inline Storage System (ISS), Milwaukee’s CSO and SSO volumes averaged well above 8 billion gallons per year (MMSD). Since completion of the ISS, that average has dropped to just above 1 billion gallons per year (MMSD). The number of overflow events has also dropped significantly, from 50-80 overflow events before construction of the Deep Tunnel down to an average of between 2 and 3 events per year (MMSD). A lawsuit in the late 1970’s forced Milwaukee to seek solutions to its severe dumping problem. Thus, a $3 billion project was initiated to improve the sewer system and virtually eliminate dumping (MMSD). The result of this project is the Deep Tunnel.

            So, what is the Deep Tunnel, and how does it work? Basically, the Deep Tunnel is simply an enormous system of sewers very deep underground. It is very similar to Chicago’s TARP system, which was installed almost 10 years earlier. Excess wastewater is stored in these tunnels until the treatment plants have the capacity to treat it (MMSD). The tunnels are between 120 and 330 feet underground. Thus far, there have been two phases of the Deep Tunnel project. Phase 1, completed in 1994, consisted of a 17-mile long system of tunnels which could hold up to 405 million gallons of wastewater (MMSD). Phase 2, which was expected to go online in 2005, is 7.1 miles long and can hold an additional 88 million gallons of wastewater (MMSD). Evidence has shown that Milwaukee’s Deep Tunnel system has been very effective at lowering both the number and volume of sewer overflows, but in times of heavy rain the system can still become overwhelmed. In this case, sewage is likely to back up into peoples’ basements. “MMSD’s highest priority during heavy rain is to prevent basement backups. Unfortunately, one of the only ways to provide relief to the sewer system and stop the flows from backing up is to have an overflow of wastewater” (MMSD).

Overflows have not completely ceased. In fact, the city set a record in 2004 by dumping 4.6 billion gallons of sewage into Lake Michigan in one overflow event (however, a year later, the MMSD lowered that figure to only 1.2 billion gallons. It remains unclear what the actual amount was) (MMSD). Between 1994 (when the Deep Tunnel was completed) and 2004, "43 SSOs...discharged more than 935 million gallons of full-strength, untreated sewage, and at least 24 CSOs...discharged more than 12 billion gallons of raw sewage and stormwater" into Milwaukee's rivers and Lake Michigan (Dorfman, 51).
            Besides not completely mitigating the problem of overflows in Milwaukee, there have been other problems with the Deep Tunnel system since it was installed. In 2001, the Red Star yeast company sued the MMSD, stating that “raw sewage leaking from the deep tunnel system has contaminated a well used by the Red Star Yeast plant in Milwaukee” (Rohde and Schultze). The fear is that cracks in the Deep Tunnel have allowed sewage to seep down and contaminate the groundwater. According to the lawsuit, “fecal contamination turned up periodically at the well after the tunnel opened in late 1993” (Rohde and Schultze). A 2000 study by the Milwaukee Journal Sentinel found that “the tunnels frequently leak, even when not completely filled, and have polluted groundwater. The sewerage district doesn't see this as a problem and has no plan to fix it; officials at the state Department of Natural Resources have known about it for five years and said they are concerned but not to the point of ordering remedial action” (Rohde). If the sewerage district does not see contaminating groundwater as a problem, and the DNR is not about to do anything about the recognized problem, it comes down to concerned citizens to take action and put an end to this dangerous mismanagement.

            The MMSD does currently have an overflow reduction plan underway. This plan combines several initiatives, which, when enacted, should help curb the problem of overflows. These initiatives include: additional storage, maintenance and upgrading of monitors and weather reporting systems, upgrading treatment plants, sewer construction and rehabilitation, stormwater reduction, and flood management (MMSD). These projects, with a combined cost of over $900 million, are expected to be completed by 2010. 

Citizen Environmental Action:

            Milwaukeehas a strong contingent of citizen groups fighting for improved wastewater management. The outrage that followed the 1993 cryptosporidiosis outbreak is still strong. This is evident each time the city is forced to dump sewage into Lake Michigan, when a wave of angry letters and editorials are sure to follow. Active citizen groups in the area include: Citizens for a Better Environment, Friends of Milwaukee’s Rivers, Keep Greater Milwaukee Beautiful, and the Alliance for the Great Lakes.

            Friends of Milwaukee’s Rivers and the Alliance for the Great Lakes have been in a tough legal battle recently with the MMSD. The two groups “filed suit in U.S. District Court in March 2002, charging that MMSD had violated the Clean Water Act by discharging about 1 billion gallons of raw industrial and domestic waste to area waterways since 1995 (Alliance). Though this case was dismissed in September of 2004, the groups appealed the case the following month (Alliance).

Milwaukee citizens have also gotten invloved with "Adopt-a-beach" campaigns to ensure beach and lake water quality. Hikers, boaters, swimmers, beach goers, and other residents of Milwaukee have reported diminished enjoyment of what should be the city's greatest asset. People are starting to make their voice heard through editorials and writing/speaking to elected representatives in the city.
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One of Milwaukee's Harbors (

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    Aerial View of Milwaukee (

sailboat in CSO plume
A sailboat in Lake Michigan nears the edge of a CSO plume with "unknown contents."
(link to Milwaukee Journal Sentinal Article, May 29, 2004).

citizen beach cleanup
Milwaukee youth participating in "Adopt-a-Beach" at Bradford Beach, one of Milwaukee's most polluted beaches.

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