Chlorine unnecessary to make tubewell water safe: Study

FE Team | Published: May 04, 2015 00:00:00 | Updated: November 30, 2026 06:01:00

Although chlorine is widely used for making water safe and clean, an ICDDR,B study suggests that safe storage and handling practices are sufficient for reducing tube-well water contamination and child diarrhoea without using chlorine, reports UNB.
A new randomised controlled trial led by ICDDR,B investigators has shown that drinking water drawn from tube-wells is contaminated with faecal pathogens during the handling and storage of water at the household, demonstrating that this contamination, which causes waterborne illnesses like diarrhoea, is largely preventable through the consistent practice of safe storage methods.
Water chlorination is the process of adding chlorine or hypochlorite to water. This method is used to kill certain bacteria and other microbes in tap water as chlorine is highly toxic. In particular, chlorination is used to prevent the spread of waterborne diseases like diarrhoea, dysentery and typhoid.
The trial enrolled 1,800 households in a rural area of Bangladesh and randomly assigned them to one of three different groups - a control group that received no intervention, a safe storage group and a group that were provided with both safe storage and chlorine tablets for the treatment of their drinking water.
The groups were then monitored and compared for one year to measure the impact of the different interventions on caregiver reported prevalence of childhood diarrhoea and level of water quality.
Households in the safe storage group were provided with a free safe storage container - as an alternative to traditional storage vessels like the kolshi, which has a wide brim that is vulnerable to contamination by contact with hands.
Households in the combined safe storage and chlorine treatment group were given additional chlorine water treatment tablets.
Both intervention groups showed a significant reduction in diarrhoea among children under 2 years of age as reported by caregivers, and an improvement in tested water quality compared to the control group in which households received nothing. But interestingly, the scientists found that there was no real benefit to the addition of chlorine treatment.
The study shows that the contamination of household drinking water happens after it has been drawn out of the tube-well source, the scientists said, adding that contamination is preventable. Chlorine treatment is, therefore, an unnecessary step for making the water safe.
Dr Leanne Unicomb, a co-author of the study, said these findings are significant because they imply that rural Bangladeshi households using tube-well water for drinking may only need to purchase and maintain a durable, low cost, dedicated household safe water storage vessel and make a modest behaviour change in order to see a large improvement in the safety of their water.