Norwegian Institute of Public Health, Section of Zoonotic, Food- and Waterborne Infections, P.O. Box 222 Skøyen, 0213 Oslo, Norway E-mail: firstname.lastname@example.org; University of Oslo, Faculty of Medicine, Institute of Health and Society, Oslo, Norway.
Water supply systems, in particular small-scale water supply systems, are vulnerable to adverse events that may jeopardise safe drinking water. The consequences of contamination events or the failure of daily operations may be severe, affecting many people. In Norway, a 24-hour crisis advisory service was established in 2017 to provide advice on national water supplies. Competent and expert advisors from water suppliers throughout the country assist other water suppliers and individuals who may be in need of advice during an adverse event. This paper describes the establishment of this service and experiences from the first three years of its operation. Since the launch of the service, water suppliers across Norway have consulted it approximately one to two times a month for advice, in particular about contamination events and near misses. The outcomes have helped to improve guidance on water hygiene issues at the national level.