Treatment

This was America's first large-scale activated sludge plant. The successful operation of Milwaukee's sewage treatment plant led the way for many other American municipalities to adopt its methods of efficient environmental recycling.

Prior to 1925, sewage and industrial waste from the City of Milwaukee and its suburbs (then population 500,000) was discharged to the Milwaukee, Menomonee, and Kinnickinnic rivers, which converge in Milwaukee and flow together through a single outlet into Lake Michigan.

Clarifying the turbid waters of the Mississippi River for use as drinking water was a formidable challenge. The Chain of Rocks Water Purification Plant provided the first application of a system of flocculation, sedimentation, and rapid sand filtration for water purification.

The system played a major role in reducing the impact of St. Louis' typhoid and cholera epidemic of 1903 that claimed 287 lives. Continued improvements to the plant reduced that number to 91 by 1914. It is estimated that 1,900 lives were likely saved between 1903 and 1915 due to the filtration system.