One of the most quoted WASH statistics was recently “downgraded”. For every $1 invested in water and sanitation, not $8 but “only” $4 is returned in economic returns through increased productivity. This recalculation , says the World Health Organization, is mainly a result of higher investment cost estimates and the more complete inclusion of operation and maintenance (O&M) costs.
Providing a better insight into O&M costs has been one of the achievements of the WASHCost project of the IRC International Water and Sanitation Centre. WASHCost has published minimum benchmarks for costing sustainable basic WASH services in developing countries . The project collected data from Burkina Faso, Ghana, Andhra Pradesh (India) and Mozambique.
The main message is that spending less than the minimum benchmarks will result in a higher risk of reduced service levels or long-term failure. NGOs claiming that “US$20 can provide clean water for one person for 20 years” have clearly forgotten to include annual recurrent costs for operation and maintenance, capital maintenance and direct support.
The real cost for 20 years of basic water supply from a borehole and handpump would be, per person, between US$ 20 and US$ 61 for construction plus US$ 3-6 every year to keep it working. In total for the 20 years this would amount to US$ 80 to US$ 181 per person.
Similarly, for the most basic sanitation service, a traditional pit latrine, the combined costs would be US$ 37 – 106 per person over 20 years.
WASHCost provides figures as well for the capital and recurrent costs of piped water schemes, and VIP and pour-flush/septic tank latrines.
WHO used WASHCost data, among others, for the above-mentioned recalculation of benefit-cost ratios for water and sanitation investments. At the global level, WHO calculates that the benefit-cost ratio for water has declined from 4.4 in their original study  to 2.0 in the new study , and from 9.1 to 5.5 for sanitation. Combined water supply and sanitation interventions have a benefit-cost ratio of 4.3. A more sobering statistic from the WHO study is that it still may take 20-30 years to achieve universal coverage.
Other mediagenic WASH statistics have come from the Economics of Sanitation Initiative (ESI) of the Water and Sanitation Program (WSP) . In 2012, ESI calculated that inadequate sanitation costs 18 African countries around US$ 5.5 billion each year and that it costs Pakistan up to 3.9% of GDP. Previous ESI studies provided these figures on the percentage of GDP lost through poor sanitation: Bangladesh – 6.3%; India – 6.4%, Indonesia – 2.3%, Cambodia – 7.2%, Lao PDR – 5.6%, The Philippines – 1.5% and Viet Nam – 1.3%.
One final statistic, released by the London School of Hygiene and Tropical Medicine for Global Handwashing Day: the lives 603,000 children aged 1-59 months could be saved annually from diarrhoea and pneumonia by handwashing with soap .
 Hutton, G., 2012. Global costs and benefits of drinking-water supply and sanitation interventions to reach the MDG target and universal coverage. Geneva, Switzerland: World Health Organization. WHO/HSE/WSH/12.01. Available at: <washurl.net/emq8c7 >
 IRC, 2012. Providing a basic level of water and sanitation services that last : cost benchmarks. (WASHCost Infosheet ; 1). The Hague, The Netherlands: IRC International Water and Sanitation Centre.
Available at: <www.washcost.info/page/2386>
 Hutton G. and Haller, L., 2004. Evaluation of the non-health costs and benefits of water and sanitation improvements at global level. Geneva, Switzerland: World Health Organization. WHO/SDE/WSH/04.04.
Available at: <washurl.net/et3px7>
 WSP – Economics of Sanitation Initiative
 Greenland, K., Cairncross, S. and Curtis, V. 2012. What can hand hygiene do for the world? London, UK: Environmental Health Group, Department of Disease Control, London School of Hygiene and Tropical Medicine.
Available at: <washurl.net/4fmsqr>