Each year over 1 million children under the age of five die from diarrheal diseases, a leading cause of which is unsafe drinking water.1 Even when diarrheal episodes are not fatal, chronic diarrhea in early childhood can contribute to malnutrition, with potential long-term consequences for child development. Governments and donors commonly fund the construction of new or improved water sources to combat the contamination of water with the fecal-oral pathogens that cause diarrhea. However, recontamination when water is transported or stored remains a problem, even if source water is uncontaminated.2 In response, the World Health Organization has promoted the use of dilute chlorine, an approach which not only disinfects water, but provides ongoing protection from recontamination for over 24 hours.3
Worldwide, 780 million people remain without access to improved drinking water.4 Wells, springs, and rivers are the main sources of water, and for these people, chlorination can be a crucial healthy behavior to adopt. The standard approach to encourage rural populations to adopt chlorination has typically been via social marketing—the promotion and sale of small bottles of chlorine through the private sector. Despite the significant health benefits, and relatively low price of chlorine ($0.30 for a family of five for a month in Kenya5), adoption remains low. Even where higher adoption rates have been possible, it usually requires substantial resource injections and generally adoption does not sustain after the marketing efforts end.
From 2003 to 2010, J-PAL affiliates Michael Kremer, Edward Miguel, and Sendhil Mullainathan, along with Clair Null, Jessica Leino and Alix Zwane, conducted a suite of randomized evaluations to investigate ways to improve water quality in rural Kenya. In their first study, researchers and partner NGOs sought to find a cost-effective way to reduce diarrheal disease by improving water quality at the source. Under the “Spring Cleaning” program, community springs were encased in concrete, forcing water to flow through a pipe rather than seeping from the ground, thus preventing contamination from groundwater. This simple infrastructure investment reduced fecal contamination at the source by 66 percent. However, much of this improvement was lost in users’ home water supply due to recontamination during transport and storage. For more about this project, see the related evaluation page.
Building upon these results, the researchers conducted a second set of randomized evaluations to investigate the role of price in determining households’ use of chlorination products. In the first phase, households were provided with a seven-month supply of WaterGuard, a point-of-use chlorination product, and a storage container designed to prevent contamination. This group was subdivided into treatment arms receiving (1) coupons for a 50 percent discount on bottles of WaterGuard, or (2) additional verbal persuasion messages, or (3) no coupons or messages. The free supply increased chlorination by 52 percentage points, a large effect relative to the 2 percent starting level. However, only 10 percent of the coupons for discounted WaterGuard were redeemed, and additional persuasive messages about the product did nothing to boost demand, suggesting that both price and convenience play an important role in households’ decisions to take up water treatment products.
In the second phase, researchers compared multiple treatments designed to increase chlorine take-up, including persuasion messaging, promotion from members of the local community, and access to chlorine dispensers combined with local promotion. Paid community-based promoters who provided reminders through home visits initially increased chlorine take-up by about 30 percentage points, but this effect was not sustained after payments to promoters ended, making this an expensive long-run strategy. To combine the advantages of reduced cost, convenience, and social norms for promoting chlorine use, researchers designed and tested a point-of-collection chlorine dispenser system that provided a free supply of chlorine at local water sources. Chlorine dispensers, in combination with the paid promoters, increased take-up by 53 percentage points, and take-up was sustained 30 months into the program, even after payments to promoters had ended. For more about this project, see the related evaluation page.
Innovations in Water Treatment
The Chlorine Dispenser System (CDS) offers an innovative approach to increasing the adoption of water treatment by rural populations, thereby reducing diarrheal diseases among children. A point-of-collection dispenser system in combination with community promoters was successful at increasing adoption of chlorinating drinking water via the dispenser, and sustaining this behavior change even two years after payments to the promoters ended.
The approach was designed to take advantage of insights from behavioral economics, helping people overcome barriers to chlorine adoption: The dispenser hardware provides a visual reminder to treat water when it is most salient—at the time of collection. The source-based approach makes drinking water treatment convenient because the dispenser valve delivers an accurate dose of chlorine to treat the most common transport container, while the public nature of the dispenser system also contributes to learning and habit formation. The promoters also provide frequent reminders and encouragement to use the product. As promoters are members of the community, their local knowledge, trust, and social influence may have contributed to their success in driving adoption.
At scale, the cost of the CDS could be as low as $0.50 per person per year, much cheaper than home delivery (or retail sale) of individual chlorine bottles. This cost includes both hardware and the recurring costs of chlorine refills, dispenser management, and maintenance, making the dispenser highly cost-effective.
Bringing the Chlorine Dispenser System to Scale
Evidence on the effectiveness of the point-of-collection chlorine dispenser system has provided the impetus for bringing this technology to scale. The CDS is currently being scaled up by Dispensers for Safe Water
, an initiative at Innovations for Poverty Action (IPA)
, in the Western and Nyanza Provinces of Kenya. As of April 2012, approximately 2,124 dispensers are currently in place, providing access to chlorine for an estimated 424,800 people, and averting an estimated 61,556 diarrhea episodes in children under three since October 2009.
The CDS enjoys extensive support from local communities and has received financial and in-kind investments from partners including the Ministry of Public Health and Sanitation and Ministry of Education in Kenya, local governments in western Kenya, and the regional water service provider for much of western Kenya. Primary funding has been provided by the Bill & Melinda Gates Foundation.
Over the next five years, IPA aims to provide access to safe water via dispensers for 5 million people in Kenya, including 2 million children under the age of five.
With support from the Bill & Melinda Gates Foundation, the Chlorine Dispenser System is being piloted in other countries. In Haiti, an estimated 20,000 people now have access to chlorine dispensers. Pilot programs are also underway in Bangladesh, India, and Uganda, and IPA is investigating the potential for dispensers in several other countries in Africa and South Asia.
1 UNICEF, 2011. “Levels & Trends in Child Mortality: Report 2011.” Prepared on behalf of the United Nations Inter-agency Group for Child Mortality Estimation. Available online at http://www.unicef.org/media/files/Child_Mortality_Report_2011_Final.pdf
2 Wright, Jim, Stephen Gundry and Ronan Conroy. (2004). “Household drinking water in developing countries: a systematic review of microbiological contamination between source and point-of-use.” Journal of Tropical Medicine and International Health 9: 106-17.
3 Lantagne, Daniele. (2008). “Sodium hypochlorite dosage for household and emergency water treatment.” Journal of the American Water Works Association 100, (8): 106-119.
4 World Health Organization/UNICEF, 2012. “Progress on Drinking Water and Sanitation: 2012 Update.” Available online at http://www.who.int/water_sanitation_health/publications/2012/jmp_report/en/
5 Kremer, Miguel, Null, and Zwane. “Water Technologies case study: what works best in poor countries,” Boston Review, September/October 2008. Available online at http://bostonreview.net/BR33.5/miguel.php