Small drinking water supplies across the Nordic region face disproportionate risks of non compliance in faecal contamination and, of waterborne disease outbreaks. They include a large number of very small and unregulated systems and serve around 4,5 million inhabitants, or 17% of the Nordic population. The main conclusion is that the small water supplies are the weak link in providing safe water for all citizens of the Nordic region and fulfilling the UN SDG no. 6 as well as the requirements in the new EU Drinking Water Directive. Our work reveals opportunities to use existing knowledge and resources to improve small drinking water systems. Our specific recommendations would substantially improve the resilience of small water supplies to diverse threats and enhance drinking water safety for many. The general lessons have widespread applicability beyond the region and arguably worldwide.