The E. B. Bain Water Treatment Plant is part of a larger civic water treatment facility that includes elements from the 1880s and 1920s, but the dominant feature is the water treatment plant of 1939-1940. Olsen had been involved in planning a 1923 expansion of the old water treatment plant, but with Raleigh’s growth in the 1920s and 1930s, it became inadequate. A large new plant was authorized by the city, with the Public Works Administration providing substantial funding and plans and specifications drawn up by Olsen. Incorporating the latest technology in water treatment, the plant was the city’s sole source of treated water from 1940 to 1967. In contrast to Elizabeth City, Raleigh experienced rapid growth in the post-World War II era. New water plants were required in the 1960s and later, and the Bain plant was taken out of service in 1987. Long unused, it has been the focus of various preservation efforts. The main building is a massive 3-story masonry edifice, with a concrete frame clad in Flemish bond brickwork and cast stone trim in a restrained modernist style. Some of the vast interior spaces are treated as formally as civic buildings of the time.