The Water Technology Center (TZW) is the centre of applied water research of the DVGW, the German Gas and Waterworks Association. The TZW co-operates with water works by doing joint research projects and supports the DVGW in development and transfer of the Technical Guidelines. The TZW is located in Karlsruhe with branches in Dresden and Hamburg and has about 150 employees. The TZW is involved in all questions concerning water chemistry, water technology, microbiology, site management, groundwater and soil, material testing, corrosion and distribution systems. It is initiator and member of several national and international joint research projects. The TZW is a member of the Global Water Research Coalition (GWRC) and the association of European Water Research Institutes (EWRI) providing a platform for co-operation in the field of international water research.