On 21 September 2004, the World Health Organisation issued new drinking water guidelines to help prevent water-related outbreaks and disease. WHO’s updated Guidelines for Drinking-water Quality (GDWQ) will help regulators and water service providers maintain and improve the quality and safety of their drinking water.

"This is an extremely important change in orientation from a public health point of view. The revised Guidelines will allow public health management to focus on prevention of microbial and chemical contamination of water supplies," said Dr Kerstin Leitner, WHO Assistant Director-General for Sustainable Development and Healthy Environments. "And they have as much applicability whether we are talking about an urban drinking water system in North America, or protected wells in the developing world. This new approach exhorts all parties working on drinking water provision and control to act in such a way that outbreaks of water-borne diseases can be further reduced."

The updated Guidelines represent a paradigm shift in advice - from a remedial to a preventive approach - on how to manage the provision of drinking water, both in the developed and developing world, in large urban settings and in the rural areas or villages. The recommended approach for regulators and operators is to manage drinking water quality in a holistic, systematic way.

This third edition of the WHO Guidelines for Drinking-water Quality is thought to be the most significant water-related public health development since the introduction of chlorine.

The new edition has reviewed and revised the recommended values for chemical limits in drinking water in line with the latest scientific evidence. The GDWQ reconfirm guideline values for over 100 chemicals. Because routine monitoring for all of the chemicals is not possible, the guidelines set out practical approaches to ’rule out’ some chemicals and to prioritize others using readily available information.

 Water for Health: WHO Guidelines for Drinking-water Quality
 WHO World Water Day Report - Water for Health: taking charge