Synopsis Simple techniques for treating water at home and storing it in safe containers could save a huge number of lives each year" WHO and UNICEF 2005 Lack of access to safe drinking water, together with inadequate sanitation and hygiene, is the overwhelming contributor to the 1.8 million annual deaths caused by diarrhoeal disease. Providing safe and reliable water services to the 1.1 billion people who currently lack access to improved water sources is an essential long term goal that will yield great health and economic benefits. Less well known is the large potential contribution that housholdlevel water quality intervention can make to immediately improve the health of the most vulnerable.