One in three...
2.3 billion people in the world do not have access to adequate sanitation, one in three of the world's population.
(WHO/UNICEF Joint Monitoring Programme (JMP) Report 2015 update
For every $1 invested in water and sanitation, an average of at least $4 is returned in increased productivity.
(Hutton, Global costs and benefits of drinking-water supply and sanitation interventions to reach the MDG target and universal coverage, WHO, Geneva, 2012: page 4)
One study estimates that funding for water and sanitation infrastructure is lacking by US$115 million a year in Sub-Saharan countries. (Africa Infrastructure Country Diagnostic (AICD) Study), while WHO gives a global estimate of $535 billion needed in new capital investment to reach universal access, or $26.75 billion per year between 2010 and 2030. (Hutton, WHO, 2012)
Around 315,000 children under-five die every day from diarrhoeal diseases caused by dirty water and poor sanitation. That's 900 children per day, or one child every two minutes.
Every year, around 60 million children are born into homes without access to sanitation.
(UNICEF, 2006 - Progress for Children)