 
		 
		 
		Diagram Showing Decreased Amount of Dissolved Oxygen in Delaware River, 1913
 
		Thomas Run sewer outlet at Cobbs Creek
 
		Thomas Run sewer outlet during construction
 
		Delaware River at Arch Street from the New Jersey side, 1914
 
		Cohocksink Sewer System outlet at Laurel Street
 
		Bacteria in Delaware River, Torresdale Filters, 1913
 
		Color Diagram of Plan for the Collection, Purification and Disposal of the Sewage of the City of Philadelphia
 
		Fairmount Park, bird’s eye view from Lemon Hill, detail
 
		Swimmers at Pier 126, Delaware River, July 15, 1918
 
		Allegheny Avenue Sewer at Pier 126, 1918
