Just 10 years ago over a billion people lacked access to an improved drinking water source, and in 2008 this estimate dropped to 884 million (WHO/UNICEF 2011). In 2010 the Millennium Development Goals (MDG) drinking water target, which called for halving the proportion of the global population lacking sustainable access to safe drinking water between 1990 and 2015, was achieved ahead of schedule, though with substantial inequality of coverage by continent (WHO/UNICEF 2012). In 2012 the estimate stood at 780 million, and in 2015 an estimated 605 million people will still lack access to an improved drinking water source (WHO/UNICEF 2012). Despite this progress, the lack of safe drinking water continues to yield a substantial morbidity and mortality burden in the developing world, a burden largely borne by children under the age of 5, and roughly half of the developing world population is affected annually by diseases associated with inadequate water and sanitation (United Nations Millennium Project 2005). With the global population poised to rise from seven billion to over nine billion by 2050 and with nearly all of this growth projected to occur in developing cities (United Nations 2010), the number of people affected by water- and sanitation-borne diseases is more likely to rise than fall over the next decade.