What is a municipal water disinfection system

Automatic chlorination and child health in urban Bangladesh

detailed description

Investigators will conduct a randomized controlled trial with blinded clusters to assess the health and economic effects of access to automatically chlorinated water. The unit of randomization is about shared water points that typically supply 20 to 200 households. Shared water points connected to holding tanks compatible with water treatment technology and found to be serving more than 4 households with at least one child under the age of five. Households that have access to eligible watering points as their primary source of drinking water will be enrolled prior to installation of chlorine equipment and a baseline survey will be conducted of water quality, diarrhea prevalence and health expenditure. Based on this baseline, households are randomly assigned to control or treatment groups. The chlorination equipment is installed at the water points of the treatment group, while a doser contains vitamin C (and no chlorine) is installed in the control group. The free chlorine dose target is below <1 ppm to maintain blinding. All households are surveyed every 2-3 months for a total follow-up period of 14 to 16 months (5 to 7 survey rounds, if the budget allows).


1. Assessment of the effects of an automated chlorination system on microbially stored drinking Water quality, residual chlorine, user satisfaction, perception of water taste by the user and odor, diarrhea in children under five years of age (longitudinal prevalence) compared to a control group.

2. Compare the marginal additional costs (per person served) to install and maintain an automated chlorination system integrated with current water supply infrastructure in low-income areas of Dhaka.

3. Assess the impact of an automated chlorination system on hospital visits and health care spending.

4. Measurement of secondary results of the effects of an automated chlorination system including child weight under five years old (WAZ), age under five years old (HAZ), as, and concentrations of C-reactive protein and immunoglobin G in serum samples taken from children under five years of age (these are objective indicators of infection, such as repetitive diarrhea episodes).


The primary analyzes are treated deliberately (the investigators analyze differences in outcomes between the treatment and control groups, with the groups being defined according to their random assignment). Investigators will also perform a secondary analysis comparing the results between the two intervention and control, with the intervention group defined as the households that had free chlorine residues detected in their stored drinking water (treated on the treated analysis).