The World Health Organization (WHO) has released its updated guidelines for drinking-water quality, providing the latest global guidance to support countries in protecting public health through safe drinking-water. Yet despite progress, the challenge remains stark: 2.1 billion people still lack safely managed drinking-water, including 106 million who drink directly from rivers, lakes or other surface water sources. The new Guidelines help countries close the safety gap, providing the authoritative basis for strengthening of drinking-water quality regulations and standards, surveillance programs and risk management practices.

“Safe drinking-water is fundamental to health, development and human rights,” said Dr Rüdiger Krech, Director a.i., Department of Environment, Climate Change, One Health & Migration at the World Health Organization. “These updated Guidelines help countries focus resources where they matter most: preventing contamination, managing risks before they become health threats, and ensuring that all people can rely on drinking-water that is safe.”

The updated edition reflects new evidence, implementation experience and practical lessons from countries applying risk-based approaches to drinking-water safety. It includes strengthened guidance on proactive water supply risk management, small water supplies, microbial risks and selected chemical hazards.

Framework for safe drinking-water

The Guidelines continue to emphasize a preventive, risk-based approach for ensuring drinking-water safety, the framework for safe drinking-water. The framework comprises three elements: establishment of health-based targets that should reflect the highest priority risks for inclusion in drinking-water quality regulations and standards, proactive risk management of water supplies through water safety planning, and independent surveillance to ensure water safety planning is effective and health-based targets are met. The latest update underscores the key role of governments in enabling drinking-water safety. 

Updated guidance on proactive risk management

Water safety plans remain central to WHO’s recommended approach for managing drinking-water risks. The updated Guidelines draw on extensive additional experience in applying water safety plans across different settings and system types. It also clarifies how sanitary inspections can support water safety planning, including in the identification of hazards and monitoring and maintenance activities, particularly for small water supplies.

New and updated information on microbial risks

Microbial contamination remains the most significant risk to drinking-water safety. The updated Guidelines strengthen the evidence and management guidance for all covered pathogens, including by clarifying the role of waterborne transmission and identifying potential concerns in health-care facilities. New fact sheets for emerging viruses have also been developed.

Updated guidance on selected chemicals

The new edition also updates information on pesticides used for vector control in drinking-water, reflecting WHO’s latest guidance. The Guidelines for drinking-water quality: fourth edition incorporates the first, second and third addenda and supersedes previous editions of the Guidelines, including the fourth edition that incorporated the first and second addenda, published in 2022. 

Looking ahead

WHO is initiating a more comprehensive update of the Guidelines for a fifth edition, including evidence reviews on contaminants and issues of significant concern, such as per- and polyfluoroalkyl substances (PFAS) and disinfection by-products (DBPs). This third addendum and the fifth edition process will be supported by a wider dissemination effort, including technical briefings, webinars, partner engagement and country-focused materials to support uptake in policy, regulation and practice.