Implementation of a low-cost alternating tank chlorination system for improving drinking water safety in remote highland communities of northern Thailand

ABSTRACT Graphical summary showing the alternating tank chlorination system, improved water quality and teacher knowledge, attitudes, and practices, and its practical benefits for remote learning centers. Highland community water supply systems in remote areas of northern Thailand often face microbiological contamination. This study evaluated the effectiveness of the alternating tank chlorination system for improving drinking water quality and strengthening water quality management in hill tribe community learning centers. This study aimed to determine the optimal chlorination conditions, evaluate system performance under field conditions, and assess changes in teachers' knowledge, attitudes, and practices regarding water system management. The results showed that chlorination at 1 mg/L combined with a 16-h contact time achieved complete coliform removal with a mean free residual chlorine concentration of 0.37 ± 0.16 mg/L. Field monitoring showed that 97.37% of treated water samples were free from coliform contamination. Operators' knowledge and practices improved significantly (p < 0.05), and user satisfaction with water safety, odor, and system operation was high. The alternating tank chlorination system proved to be an effective, low-cost, and user-friendly solution for improving drinking water safety in resource-limited settings. Combining with operator capacity building, the system provides a scalable approach to rural water safety management and supporting Sustainable Development Goal 6 (SDG 6).