The Chicago Sanitary and Ship Canal, historically known as the Chicago Drainage Canal, is the only shipping link between the Great Lakes Waterway (specifically Lake Michigan by way of either the Chicago River or the Calumet-Saganashkee (Cal-Sag) Channel) and the Mississippi River system, by way of the Illinois and Des Plaines Rivers. The canal also carries Chicago's treated sewage into the Des Plaines River. Before completion of the canal in 1900, the sewage in the Chicago River flowed into Lake Michigan, the city's drinking water supply. The canal is part of the Chicago Wastewater System, operated by the Metropolitan Water Reclamation District of Greater Chicago. In 1999, the system was named a Civil Engineering Monument of the Millennium by the American Society of Civil Engineers (ASCE).