Brookfield is geographically unique because the city straddles the sub-continental divide. Sewage flows originating on the eastern side of the city flow to the Milwaukee Metropolitan Sewerage District (MMSD), are treated there and are discharged to Lake Michigan, eventually ending up in the Atlantic Ocean. The western "half" of the city flows to the Fox River Water Pollution Control Center (FRWPCC) operated by the City of Brookfield. Effluent from the plant discharges to the Fox River (Illinois Fox basin) ending up in the Mississippi River and the Gulf of Mexico.
The FRWPCC is an activated sludge plant with tertiary filtration and was designed for an average daily flow of 12.5 million gallons per day (MGD). The plant can handle peak wet weather flows of 50 MGD.
The regional facility also treats some or all of the flows from the communities of the Village of Menomonee Falls, the Village of Pewaukee, the City of Pewaukee, Lake Pewaukee Sanitary District and the Town of Brookfield Sanitary District #4.
This plant was originally constructed in 1974 to treat flows of 5 MGD. Major expansions in 1985 and 2000 bought it up to its current capacity.
Tours of the plant are available and take from 1 to 2 hours.