The Water and Drainage History of Philadelphia: A seven-part course
Two reports on the state of the Schuylkill River, 1867
Fairmount Water Works, W.H. Bartlett, 1839
Fairmount Water Works from the forebay, 1833
Wooden Water Pipe, removed from Market Street, December 6, 1901
Half a Century of Clean Water
Volume of Sludge from 1,000,000 Gallons of Sewage
Diagram Showing Rate Between Bulk of Wet Sludge and Its Percentage Moisture
Sludge Drying Beds, Essen Nord, Germany
Effects of Expansion of Gas Bubbles in Enscher Sludge Shown in Right-Hand Cylinder