Selection of photographs taken of an historic slow sand water filtration system in Washington, DC. Part of the McMillan Reservoir complex, this engineering feat was completed in 1902 and still used until the mid 1980's. Site has remained largely untouched since then. Plans for redevelopment have been studied for years, with a recent resurgence of interest. Groups are lobbying to retain some of the incredible infrastructure and have it integrated with the new buildings.