The World Health Organization (WHO) continues to support Thailand in strengthening water safety through collaboration with the Metropolitan Waterworks Authority (MWA) and the Department of Health (DOH), Ministry of Public Health to enhance the implementation of Water Safety Plans (WSPs) implementation.
Serving more than 10 million people, MWA has implemented Water Safety Plans for over a decade as part of its efforts to ensure safe drinking-water. This work is supported by ISO 9000 and HACCP-certified operations at its major treatment plants.
/countries/thailand/the-water-safety-plan-audit-opening-by-mwa-who-thailand-and-expert.png?sfvrsn=3509eae9_2 "The Water Safety Plan audit opening by MWA WHO Thailand and expert")
The Water Safety Plan audit was officially opened by Ms Suwara Thawitchasri, Governor of the Metropolitan Waterworks Authority (MWA), joined by MWA senior management, Dr Olivia Nieveras of WHO Thailand, and external expert auditor Mr Asoka Jayaratne. Photo credit: MWA
As part of its technical cooperation with Thailand, WHO facilitated a WSP audit of MWA in 2026 to further strengthen risk-based water management and support continued alignment with WHO recommendations and international good practice. Building on earlier WSP audits conducted in 2016 and 2021, WHO provided financial support for the engagement of international Water Safety Plan expert, Mr. Asoka Jayaratne, who contributed independent technical expertise informed by international experience and experience. This collaboration supports continuous improvement and capacity strengthening in drinking water safety management.
The audit applied WHO-recommended approaches and a consistent scoring system, allowing MWA to benchmark progress over time. It included a review of WSP documentation and field assessments covering selected treatment processes and distribution systems. Representatives from Thailand’s DOH participated as observers, helping strengthen collaboration between the water supplier and the national public health authority.
/countries/thailand/highlights-from-the-2026-water-safety-plan-audit.jpg?sfvrsn=d6f69bee_2 "Highlights from the 2026 Water Safety Plan audit")
Highlights from the 2026 Water Safety Plan audit, including technical discussions, document reviews and field assessments of selected water treatment and distribution systems, with the international water safety expert. Photo credit: MWA
The audit found substantial progress in the implementation of WSPs over the past decade, reflecting MWA’s sustained efforts to operational performance and public health protection. The audit also identified opportunities to further strengthen risk management practices and continued alignment with WHO recommendations and international good practice.
Priority areas for improvement included strengthening risk assessment processes, comprehensively reviewing and updating the risk register, improving operational monitoring, reviewing filtered water turbidity targets, optimizing treatment performance monitoring, improving inspection practices for water storages, and strengthening backflow prevention measures at the customer interface.
These findings provide a practical basis for further strengthening preventive risk management across the water supply system, enhancing system resilience and water quality assurance. WHO will continue to facilitate access to technical support and knowledge exchange to assist MWA and DOH translate audit recommendations into evidence-informed actions.
Through this continued collaboration, WHO remains committed to supporting Thailand’s efforts to strengthen drinking -water safety and protect public health. The 2026 audit marks an important milestone in strengthening water safety systems and highlights the value of collaboration among national utilities, public health authorities, and WHO in advancing sustained improvements in drinking-water quality.