A recipient of the U.S. Water Prize and many other awards, MMSD is most proud of its record of 98.4%, since 1994, for capturing and cleaning wastewater from 28 communities in a 411 square mile area. Many metropolitan areas struggle to capture and clean the national goal of 85% of all the rain and wastewater that enters their sewer systems.
MMSD 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.
Protecting public health and the drinking water supply for millions of people takes the expertise of hundreds of specially skilled and dedicated employees. MMSD is regarded nationally as a leader in wastewater treatment, flood management, and green infrastructure.
The first sewers were built more than 130 years ago and carried sewage, untreated, and stormwater directly to the rivers and Lake Michigan. These first sewers were “combined” sewers because sanitary and industrial waste were not separated from stormwater. Everything poured right into the rivers. Sewer construction was in its infancy and the prevailing public attitude was that waterways were free to use for disposal of wastes. In the late 19th Century, abuse of the waterways became more rampant and the rivers began to stink and pose health risks.
The City of Milwaukee recognized the adverse effect of polluted rivers and brought in experts to fashion a solution. The process proceeded in "fits and starts" as the issue of how to protect our waterways became embroiled in politics. Eventually, the public was heard. Politicians debated and support grew for a lasting remedy. The Sewerage Commission of the City of Milwaukee was established in 1913, and the arduous job of designing and building a sewage disposal system began.
In 1914, the Sewerage Commission experimented with a new approach for wastewater treatment involving microscopic organisms - the activated sludge method which was being developed in Europe. A pilot plant was constructed on the tip of Jones Island. This pilot plant was eventually replaced by the Jones Island Sewage Plant in 1925. The new plant used the waste activated sludge process. It was the largest facility in the nation to harness nature in order to clean wastewater, by having microorganisms feed on pollutants. But there was a problem with what to do with the resulting material that remained—the abundant volume of microbes. Rather than disposing of the plentiful, nutrient-rich microbes into landfills, in 1926 Milorganite® fertilizer was created.
In 1972, the State of Illinois sued both the Metropolitan Sewerage Commission of Milwaukee County and the City of Milwaukee Commission, a legal battle that went all the way to the U.S. Supreme Court. In 1977, the District reached an agreement with the Wisconsin Department of Natural Resources (DNR) to reduce overflows. Both the Illinois lawsuit and DNR agreement led to the development of the Water Pollution Abatement Program (WPAP), which resulted in major improvements to the regional wastewater treatment system.
After extensive planning and public input, construction on the WPAP began around 1979 to repair and expand the entire metropolitan area wastewater conveyance and treatment system. The cornerstone of the WPAP - Milwaukee's Deep Tunnel System – involved 19.4 miles of Deep Tunnels dug 300 feet underground to help reduce sewer overflows and basement backups. It started operating in 1993.
The region invested $3 billion in the WPAP improvements with $1 billion going towards the Deep Tunnel. Water pollution from sewer overflows dropped drastically from the 8 billion to 9 billion gallons that occurred, on average, every year prior to the tunnel.
MMSD invested another $1 billion in an Overflow Reduction Plan that was completed in 2010. Part of the effort led to two additions to the Deep Tunnel system that currently stores 521 million gallons and stretches 28.5 miles long. Our current financial forecast through 2025 calls for investing $1.5 billion in clean water infrastructure, flood management, and debt financing to help protect public health and Lake Michigan.