Small drinking water supplies across the Nordic region face disproportionate risks of non‑compliance in faecal contamination and, of waterborne disease outbreaks, and lag in adopting risk-based approaches (RBA). The small water supplies, including a large number of very small and unregulated systems, serve around four and a half million inhabitants, or 17% of the Nordic population.
RBA improves drinking water quality and public health, is required in the EU Drinking Water Directive (EU DWD), and is recommended in World Health Organization guidelines. Legal frameworks requiring RBA exist across the Nordic region but implementation in small systems is negligible in some regions. Emerging challenges to water suppliers to include climate change which is altering hazard profiles with increasing temperature and extreme weather events with an uncertain future trajectory that we found to be insufficiently reflected in RBA policy and practice. Similarly, lessons from COVID‑19 and other recent pandemics confirm that preparedness should also be part of RBA. Our study revealed precarious staffing, delayed maintenance, surveillance disruptions, and supply chain dependencies during the pandemic, even though automation and digital communications supported continuity during the pandemic.
Official surveillance capacity - that is the day-to-day work of health inspectors and national administrations - is overloaded, especially for the small supplies. Most Nordic countries lack even the foundation of a comprehensive register that includes very small and unregulated systems where risks are greatest. Regular national statistics on water quality are not always available although required in some of the national drinking water legislations.
The finding show that small systems have specific challenges and are not managed as effectively as the large ones. However, the small systems should not be understood as downscaled large systems. Instead, small supplies should be helped with additional guidance and regulations that are, suitable for their specific, individual characteristic. The training of operators of small supplies is insufficient in some of the countries whereas training is legislatively required in others and typically the information provided to small system customers is inconsistent and difficult to access.
The new EU-DWD (2020/2184) states that RBA should be applied by all regulated water suppliers, including small water suppliers. Our work reveals that this remains to be done and that the substantial benefits, such as reducing incidents, raising compliance and enhancing resilience are unrealized and maybe beneficially achievable in all (including non-regulated) small systems. It was also found that achieving these through down-scaling approaches applied to larger systems is impractical and probably ineffective; and that an effective response requires both strengthening of support systems and strengthening of individual water supply systems.
Strengthening of the nation-wide support systems would be beneficial in most countries. This includes: the surveillance function, such as by strengthening inspector capacity; making RBA resources and activities small‑system‑fit and accessible in relevant languages; improving data accessibility and transparency to users; establishing or improving national registries of water supplies to include the numerous small (50-500 people) and smallest (<50 people) water systems, as well as requiring and enabling training for everyone involved in operating small systems. Involved stakeholders include central and local government, providers of education and training, those involved in emergency preparedness and response, and professional associations.
These support systems should collectively facilitate context-specific improvements tailored to the local circumstances of individual water supplies. Effective implementation is likely to be progressive and towards inclusion of the widespread very small systems, programmed to include all system types, and scheduled with deliberate lesson-learning and adaptation. We therefore recommend progressively extending risk-based management towards coverage of all small water supplies and developing the resilience of these systems through risk-based management, initially including adaptation to a changed climate and to pandemic resilience and ultimately towards establishing broad-based multi-threat resilience.
Our work reveals substantive opportunities for better use of existing knowledge and resources to improve small drinking water systems. It is crucial to deal with the small supplies both as indviduals and to provide support and guidance across them at scale. Our specific recommendations are practical and attainable; and together would substantively improve the resilience of small water supplies to diverse threats, across the Nordic region and enhance drinking water safety for many. The general lessons have widespread applicability beyond the region and arguably worldwide.
Based on our work on improving the drinking water quality and resilience in the small and very small water supplies in the Nordic region, our individual reports include the following specific recommendations: