After an initial difficulty in attracting customers (who were used to getting their water from public pumps and private wells and cisterns), Philadelphia's waterworks soon couldn't keep up with demand. John Davis and Frederick Graff designed a complete remodeling of the system in 1811 so that it could supply the city's growing needs.
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.