Impact of Low-Cost In-Line Chlorination Systems in Urban Dhaka on Water Quality and Child Health

October 3, 2016

Polluted water in urban poor communities transmits water-borne diarrheal diseases, such as cholera and typhoid, which can be particularly deadly to children. This evaluation studies whether a new inexpensive water chlorination method installed in community hand-pumps can reduce disease in poor communities in Dhaka, Bangladesh.

Governments in developing countries need cost-effective solutions to provide clean water to growing urban populations, especially in slums where families may share water from a central tap or hand pump. Water-borne diseases can lead to illnesses that stunt children’s growth, hurt their health and even kill.

Research area: Water Supply, Sanitation and Hygiene

Country: Bangladesh

Evaluation Sample: All poor households, with at least one child under five, that access one of 160 studied shared water points in Dhaka.

Timeline: 2013 - 2017

Intervention: Water disinfecting technology

Researchers: Stephen Luby, Stanford University; Amy Pickering, Stanford University; Peter Winch, Johns Hopkins University; Michael Kremer, Harvard University; Leanne Unicomb, icddr,b; Farhana Sultana, icddr,b; Pratibha Mistry, World Bank

Partners: Dushtha Shathya Kendra (DSK); Stanford’s Lotus Water Initiative (LWI); J-PAL Urban Services InitiativeGovernment of Bangladeshicddr,bStanford UniversityJohns Hopkins UniversityHarvard University


Studies have looked at the effectiveness of making available to households free or cheap chlorine (see: Evaluations for chlorination). But distributing chlorine requires changing people’s behavior so they use chlorine tablets or dispensers, which isn’t always easy.

This project seeks to reduce the global burden of water-related illness by developing and implementing a low-cost, in-line chlorination technology that delivers chlorine automatically when water pumps are used. The results of this impact evaluation will help inform programs seeking to ensure clean water, potentially offering an alternative approach for reducing water-borne illnesses that can harm especially children’s development.

Fully one third of the world's population- approximately 2.3 billion people- rely on shared water points, and this percentage has not changed over the past 20 years (The WHO/UNICEF Joint Monitoring Programme, 2012).


In Dhaka, more than 20 percent of the city’s 15 million residents live in slums and almost all rely on shared taps or handpumps for water. Efforts to market in-home disinfection technologies, such as chlorine products and filters, have not succeeded. Dhaka’s public water utility company has not considered installing disinfecting solutions at shared community distribution points because cost-effective technologies aren’t yet available. In this project, researchers are using an inexpensive technology to automatically add chlorine to water dispensed at public taps and shared hand pumps. The technology, developed by Stanford University, is easy to install and maintain, has no moving parts, and does not require electricity to operate.

Scott Wallace / World Bank

Intervention and Evaluation Details


The intervention will take place in low-income neighborhoods in Dhaka. Researchers will randomly select 160 shared water points that are connected to the municipal water distribution system. The shared water points will be randomly divided into two groups: Eighty will be hooked up to a chlorine dispenser, and 80 will be the control group.

The team will help the Dhaka water utility to install a simple chlorine dispenser at the shared water points in the treatment group. The local partner, icddr,b, will also conduct a one-hour education meeting with each household before the pumps are equipped with the technology. Follow-up promotional visits will be held every two months for the first six months, then once every four months for the next eight months. The group icddr,b is responsible for resupplying chlorine to the dispenser every week.


The evaluation will be a cluster randomized controlled trial involving the 160 shared water points. Each shared water points serves approximately 10-50 households. All households with at least one child living under the age of five will be enrolled.

A baseline survey, conducted before the chlorine dispensers are connected, will collect data for each household related to:

  • water quality (microbes, taste, smell)
  • incidence of diarrhea in children under five
  • weight of children
  • cost per person of installing and maintaining the new system
  • hospital visits
  • health care expenditures
  • other expenditures such as purchases of treated (bottled) water, and expenditures on fuel for boiling water

Households and water from the taps or pumps will be surveyed every two months for 14 months (seven survey rounds). After 14 months, the team will compare outcomes between households linked to shared water points with chlorine dispensers and households linked to shared water points that did not receive chlorine dispensers.

Policy Impacts

The technology studied in this evaluation represents a realistic alternative for water utilities in need of affordable and effective disinfection technologies. The low-cost water disinfectant technology has the potential to be implemented at scale, and may represent a sound public investment. Clean water decreases disease and improves human capital while reducing healthcare costs. The researchers estimate the technology can improve water quality for 360 million people in Asia, 25 million in Latin America, and 142 million in sub-Saharan Africa.