Assessing levels of safety integrity in tap water quality – A case study approach

Ensuring the safety and quality of tap water remains a critical challenge for modern water supply systems. This study presents an innovative approach by applying Levels of Safety Integrity (LSI) ˗ a concept traditionally used in industrial and information safety - to assess and enhance tap water safety. The proposed methodology integrates systematic risk assessment, hazard identification, and protective measures, within a structured framework based on probability, consequences, and vulnerability factors. The model was applied to real-world data, revealing that microbiological contamination (Clostridium perfringens) posed a high risk, classified as unacceptable (3-LSI) for sensitive consumers, necessitating immediate intervention. In contrast, flood-induced turbidity was categorized as controlled (2-LSI), requiring continuous monitoring and mitigation strategies. The case studies presented in this paper demonstrate the usefulness of the proposed research methodology, which can be applied to other water supply systems in various regions of the world. The methodology addresses the analysis of water consumers based on risk assessments, with a particular focus on priority groups, representing an innovative approach to risk analysis.