Drinking water hygiene in Germany is regulated by the Drinking Water Ordinance (TrinkwV) and standards DIN EN 806 and DIN 1988-200. The central concern is the proliferation of Legionella bacteria in stagnant, lukewarm water (25–45 °C). Preventive measures include maintaining minimum flow velocities, operating hot water storage at above 60 °C, performing regular thermal disinfection, and avoiding dead-end pipes. Pipe materials must be compatible with drinking water. Large installations with central hot water preparation are subject to mandatory Legionella testing. Installers must have specialist knowledge of hygienic planning and are responsible for fault-free execution under VOB/C.