


Color Diagram of Plan for the Collection, Purification and Disposal of the Sewage of the City of Philadelphia

Bird’s eye view of Delaware River and Philadelphia, about 1840

Commencement of laying the main on the East side of the River, 1871

Henry Disston & Sons Keystone Saw Works

Pennypack Sewage Treatment Works, 1914

Torresdale Conduit work gang, 1906
