Desalination help published with WHO drinking water standards

The World Health Organization launched the 4th edition of its Guidelines for Drinking-Water Quality (ISBN: 978 92 4 154815 1) at the Singapore Water Week on 4 July 2011 – and also launched a separate guide for desalination.

Safe Drinking-Water From Desalination (WHO/HSE/WSH/11.03) was prepared under the auspices of the WHO Drinking-water Quality Expert Group. Its guidance focuses on chemicals and microbes of particular concern in the context of desalination.

The key chemical and microbial risks associated with major operational aspects of the desalination process, such as source water quality management, treatment, and the blending of final waters, are discussed in the context of WHO Water Safety Plan framework to guide member states in effectively managing a safe drinking-water supply from desalinated sources.

This WHO guidance document is health-focused and builds on the publication Desalination technology: health and environmental impacts (Cotruvo et al), which covers the broader context of environmental, technical and operational aspects of desalination.

In addition to highlighting common challenges in providing safe and clean water, the new WHO drinking-water guidelines map out new solutions. For the first time, comprehensive good practice recommendations are provided for all levels, from household rainwater harvesting and safe storage through to policy advice on bulk water supply and the implications of climate change.

Recommendations are also included for

Drinking-water safety, including minimum procedures, specific guideline values and how these should be used;

Microbial hazards, which continue to be the primary concern in both developing and developed countries;

Climate change, which results in changing water temperature and rainfall patterns, severe and prolonged drought or increased flooding, and its implications for water quality and water scarcity, recognizing the importance of managing these impacts as part of water management strategies;

Chemical contaminants in drinking-water, including information on chemicals not considered previously such as pesticides used for disease vector control in stored drinking-water;

Key chemicals responsible for large-scale health effects through drinking-water exposure, including arsenic, fluoride and lead, and chemicals of public concern such as nitrate, selenium, uranium and disinfection byproducts.