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What is the Safe Water System (SWS)?
Why was the SWS developed?
Who is the SWS for?
Where has the Safe Water System (SWS) been used?
How is a SWS started?

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Where has the Safe Water System been used?

Project Partners

  • CDC
  • Child and Community Health Project/PROSIN
  • PSI
  • Andean Rural Health Care
  • Rotary Club of Estes Park, Colorado
  • PAHO
  • Millipore Foundation
  • Project Concern International
  • Centro Nacional de Enfermedades Tropicos
  • Ministry of Public Health
  • Peace Corps
  • Instituto Bibosi
  • Local municipalities
  • Pro Habitat
  • Universidad Mayor de San Andres
  • Ministerio de Urbanismo y Vivienda

Target Populations/Location

  • First field trial: periurban population in El Alto, Bolivia
  • Second field trial: street vendors in La Paz, Bolivia
  • Third field trial: periurban population in Montero, Bolivia
  • Social marketing trial: urban and rural populations in Santiesteban, Ichilo, and Sara Provinces in northern Santa Cruz Department
  • Expansion: 7 departments (states) of Bolivia

Project Design

  • Three successive field trials to test impact of the SWS on water quality, diarrhea, and street-vended beverages
  • Trial of social marketing
  • Large-scale implementation project

Intervention Elements

  • Sodium hypochlorite solution produced locally using appropriate technology. The brand name is CLARO.
  • Locally produced, 20-liter plastic containers with spigots
  • Community education
  • Social marketing

Project Start Date

  • Field trial one: December 1992
  • Field trial two: June 1993
  • Field trial three: September 1994
  • Social marketing (CLARO) trial: November 1996
  • Social marketing expansion project: March 1997

Results of Project Evaluations

  • In the El Alto field trial, narrow-mouth, plastic water storage vessels and 5% calcium hypochlorite solution for home disinfection of stored water were provided to a Bolivian Aymara Indian community at risk for cholera. Each of 42 families in the study obtained water from a household well; fecal coliform bacteria were found in water from 40/42 (95%) wells (geometric mean 84.7 colonies/100 ml) and 34/42 (81%) usual water storage vessels (geometric mean 57.6 colonies/100 ml). One group of families received the special vessels and chlorine (group A), a second received only the special vessels (group B), and a third served as a control group (group C). Water samples collected every 3 weeks from group A special vessels had lower geometric mean fecal coliform colony counts (p <.0001) and lower geometric mean Escherichia coli colony counts (p <.0001) than water from group B or C vessels. Adequate levels of free chlorine persisted in these vessels for at least 5 hours. The special vessels and chlorine solution were well accepted and continued to be used for at least 6 months. Use of the vessel and chlorine solution produced drinking water from nonpotable sources that met WHO standards for microbiologic quality.
  • In the Montero field trial, 127 households in two periurban communities were randomized into intervention and control groups, surveyed, and the intervention was distributed. Monthly water quality testing and weekly diarrhea surveillance were conducted. Over a 5-month period, intervention households had 44% fewer diarrhea episodes than control households (p=0.002). Infants <1 year old (p=0.05) and children 5-14 years old (p=0.01) in intervention households had significantly less diarrhoea than control children. Campylobacter was less commonly isolated from intervention than controls (p=0.02). Stored water in intervention participants households was less contaminated with E. coli than stored water in control households (p<0.0001). Intervention households exhibited less E. coli contamination of stored water and less diarrhea than control households.
  • An evaluation of the social marketing trial compared an intervention group of households using CLARO water vessels and disinfectant solution with a control group of households using traditional water treatment and storage methods. Three months after the launch of the CLARO social marketing campaign, in the intervention communities 50% of households reported using the CLARO water vessel, 34 per cent said that they were using CLARO disinfectant, but only 19% had detectable levels of chlorine in their stored water.

Within intervention communities, households that reported using the CLARO vessel or CLARO disinfectant had significantly lower fecal coliform counts than households that reported not using these products (p<0.05). During the 9-week prelaunch period, children <15 years old in intervention families had 0.22 episodes of diarrhea per person, and in control families had 0.28 episodes per person. During the 12-week post-launch period, children in intervention families had 0.12 episodes person, a reduction of 54.5 per cent, and children in control families had 0.28 episodes per person. The slope of the curve describing the weekly incidence of diarrhea in families in intervention communities showed a rate of decrease of disease that was significantly greater than in control families (p<0.05).


  • This project has scaled back because of funding and management problems.
  • CLARO water vessels and disinfectant have been used by PAHO and various NGOs to respond to a series of local, regional, and national emergencies, including flooding associated with El Nino, earthquakes, landslides, and cholera epidemics.

For More Information




Centers for Disease Control and Prevention
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Foodborne and Diarrheal Diseases Branch

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