Manholes like this give access to city’s sewer system, 1961
Sewer Inspections: Vintage Images
Thomas Run sewer outlet at Cobbs Creek
“Philadelphia Underground,” Jan. 29, 1961
“Sewer Crawlers,” January 29, 1961
1779 Revolutionary War-era map of Philadelphia and environs
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
Swimmers at Pier 126, Delaware River, July 15, 1918