1779 Revolutionary War-era map of Philadelphia and environs
Schuylkill River Hydrographical Survey 1861-66 by H. P. M. Birkinbine
The Journey of Your Flush
Color Diagram of Plan for the Collection, Purification and Disposal of the Sewage of the City of Philadelphia
Captain Sewer and Michael Nutter, 1998
30th Street Sewer
69th St. Sewer and Culvert across Lansdowne AVe.
Ventilating cover for manholes
PWD water tech at the Philly Home Show, 1960 (detail)
Lab tech, water cleaning demo, Philly Home Show, 1960
