Items

Historic resources from our archives - images, maps, documents, and more.

Diagram from sewage treatment plan for Philadelphia, 1912

Black-and-white photo of industrial tank installation with smokestacks and factories in the background

Emscher Tank Installation at Essen Nord, Germany

Black-and-white image of two cylinders on a white surface

Effects of Expansion of Gas Bubbles in Enscher Sludge Shown in Right-Hand Cylinder

Black-and-white image of a tray with three compartments and four small glass cylinders

Drain water from sludges obtained from sedimentation, septic and Emscher tanks