Training caretakers to clean community wells is a highly cost-effective way to reduce exposure to coliform bacteria

Globally, access to safe drinking water remains a significant challenge, hindering progress towards the Sustainable Development Goal (SDG) target of universal access by 2030. While infrastructure improvements are crucial, maintaining water quality is equally important. In Bangladesh, many households rely on tubewells, often classified as 'improved' sources, yet these frequently contain bacterial contamination. This study focuses on a frequently overlooked aspect of water infrastructure – cleaning practices. Existing strategies often overlook the role of well caretakers in maintaining water quality. This research investigates whether training these caretakers in effective well-cleaning techniques can be a low-cost, high-impact solution for improving drinking water quality and reducing exposure to fecal contamination, particularly coliform bacteria, in rural Bangladesh, where deep tube wells drawing from aquifers are still commonly contaminated. Previous studies have shown promise in improving water quality through cleaning interventions conducted by trained personnel, but the effectiveness of training untrained, unpaid caretakers has remained largely unknown. This study addresses this knowledge gap by using a randomized controlled trial to determine the impact of such training and identify potential cost savings and health benefits.

The existing literature highlights the significant global burden of disease and mortality associated with unsafe drinking water. While various interventions have been explored, including improved infrastructure and point-of-use/supply chlorination, challenges in implementation and sustainability persist. Water quality issues remain a significant obstacle even with improved infrastructure due to issues with maintenance and contamination introduction. Previous research has shown the potential of cleaning interventions conducted by trained professionals to improve water quality, but the effectiveness of training community well caretakers, who often lack the necessary knowledge and resources, has received minimal attention. There's a scarcity of research on how well caretakers maintain water quality in existing infrastructure. A prior pilot study in the same region demonstrated that cleaning well interiors with a chlorine solution improved water quality when done by trained staff, but the impact of training caretakers themselves was unknown. This study builds upon this prior work by examining the effectiveness of training these unpaid caretakers in a randomized controlled trial.

This study employed a randomized controlled trial to evaluate the impact of training community well caretakers on water quality. Caretakers of deep tubewells in northeastern Bangladesh were randomly assigned to either a training intervention group or a control group. The intervention consisted of a 2.5-hour training workshop on effective well-cleaning techniques, including cleaning accessible parts with a stiff brush and using a chlorine solution to wash the interior. Some participants also received cleaning supplies. Water samples were collected from all wells 13 and 17 months after the training to assess contamination levels of *E. coli* and coliform bacteria using IDEXX Colilert kits. Survey data were collected from caretakers to assess their knowledge and practices related to well cleaning. Statistical analysis, including regression models with standard errors clustered at the household level, were used to evaluate the impact of the training intervention on water quality. Cost-effectiveness analysis was performed to estimate the cost per person for preventing coliform exposure and the cost per DALY (disability-adjusted life year) and per life saved, considering the potential reduction in child mortality linked to improved water quality. The study accounted for attrition of wells and considered the potential for bias due to differences in caretaker characteristics.

Thirteen to seventeen months after the training workshops, wells with caretakers assigned to receive training exhibited significantly lower rates of *E. coli* contamination compared to control wells (13 months: 2% vs 14%; 17 months: 4% vs 19%). Rates of coliform contamination were also significantly reduced in the trained group (13 months: 3% vs 55%; 17 months: 46% vs 77%). Providing caretakers with cleaning supplies in addition to training further improved water quality and the sustained adoption of cleaning practices. The cost-effectiveness analysis revealed that the cost of preventing exposure to coliform bacteria was approximately US$80.89 per person. Modeling the potential reduction in child mortality indicated that each US$2376 spent on the intervention could avert one child death, translating to a cost of US$29 per DALY saved, ranking this among the most cost-effective interventions for improving infant health. The study further notes that caretakers assigned to training and supplies showed better recall and more regular practice of the cleaning protocol compared to those assigned to training alone; however, there was a decline in regular practice between 13 and 17 months for elements requiring chlorine solutions, potentially due to supply depletion.

The findings demonstrate the substantial impact of training community well caretakers on improving drinking water quality and reducing exposure to harmful bacteria. Even modest changes in cleaning behavior led to significant improvements in water quality. The high cost-effectiveness of the intervention, comparable to other leading interventions in infant and child health, underscores its potential as a scalable, sustainable solution for improving global access to safe drinking water. The effectiveness of the intervention can be attributed to several factors: established trust between the training providers and caretakers, training based on prior experimental data, and the inclusion of practical demonstrations. The study's results suggest that targeting well-cleaning practices through training and the provision of resources can be a significant step towards achieving SDG targets for water safety and promoting public health.

This study provides strong evidence that training community well caretakers to clean wells effectively is a highly cost-effective intervention to improve water quality and reduce the risk of waterborne diseases. The low cost per DALY averted and the potential for long-term impact make this intervention a promising strategy for improving global access to safe drinking water. Further research should focus on optimizing cleaning protocols, exploring the long-term sustainability of the intervention, and examining the generalizability of these findings to different contexts and well types.

The study's limitations include the lack of long-term data on the persistence of the intervention's effects and the absence of blinded participants and staff. Variation in the rate of training delivery (some remote, some in-person) could have affected results. The study was limited to deep tube wells in a specific region of Bangladesh, which may limit generalizability to other contexts with different well types or community structures. The reliance on self-reported data from caretakers introduces the possibility of recall bias. The lack of comprehensive quality control measures in water quality testing may affect the precision of findings.