Steam engine drawing, Frederick Graff Sr., 1815
Fourth of July, Centre Square, ca. 1812
Wooden Water Pipe, removed from Market Street, December 6, 1901
Centre Square Engine House, ca. 1807
Bethlehem Water Works, 2011
Roman Aqueduct in Segovia, Spain
Norman Lofton inspects sewer at Ditman and Sheffield, 1987
Half a Century of Clean Water: The Clean Water Act, 1972-2022
Main Pumping Stations for Philadelphia Drinking Water
Thomas Run sewer outlet at Cobbs Creek