Delaware River at Arch Street from the New Jersey side, 1914
Bacteria in Delaware River, Torresdale Filters, 1913
Sewer Demand Taken to City Hall, 7/25/32
“Philadelphia Underground,” Jan. 29, 1961
“Sewer Crawlers,” January 29, 1961
1779 Revolutionary War-era map of Philadelphia and environs
Centennial Exhibition situation plan, 1876
Color Diagram of Plan for the Collection, Purification and Disposal of the Sewage of the City of Philadelphia
30th Street Sewer
Plan for the Collection, Purification and Disposal of the Sewage of the City of Philadelphia, 1912
