Karl Imhoff

Karl Imhoff was a German civil engineer and a founding figure of modern wastewater treatment technology. From 1906 he headed the wastewater office of the Emscher Society in Germany's industrial Ruhr region, where he developed the Emscher fountain, an early anaerobic sludge treatment method, and went on to invent the settling and digestion tank that bears his name, the Imhoff tank, along with the Imhoff cone used to measure settleable solids in wastewater, both of which remain in use in sanitation engineering. Between 1922 and 1934 he served as managing director of the Ruhrverband, the regional water management authority, where he oversaw planning for five major dams. His 1906 book, translated roughly 40 times into 20 languages over the following century, became a standard reference in the field; he founded the German Wastewater Technical Association (ATV) in 1948 and received the Federal Republic of Germany's Great Cross of Merit in 1953.