1. In 1901, the Royal Insititute for Research and Testing in Water Supply and Waste Disposal is founded, becoming the Royal State Insititute for Water Hygiene in 1913, the Prussian State Institute for Water, Soil and Air in 1923, the Imperial Institute for Water, Soil and Air in 1942, before finally settling down as the Institute for Water, Soil and Air Hygiene under the Federal Health Office in 1952. In 1994, it became a department of the FEA, merging with it completely in 1999.