Existing strategies for improving global access to safe drinking water have met only limited success. We consider an unglamorous and often neglected dimension of drinking water infrastructure provision: cleaning. We randomly assigned caretakers of community wells to participate in a training workshop about how to clean wells. Thirteen to seventeen months later, wells with caretakers assigned to receive training have negligible rates of contamination with Escherichia coli (13 months: 2%; 17 months: 4%), while control wells have substantial rates of E. coli contamination (13 months: 14%; 17 months: 19%). Rates of contamination with any coliform bacteria are almost halved (13 months: control 55%, treated 30%; 17 months: control 77%, treated 46%). We estimate the cost of preventing exposure to coliform bacteria in drinking water to be US$0.89 per person and that, if scaled up, each US$2376 spent on the intervention could avoid the death of a child.

改善全球安全饮用水可及性的现有战略收效甚微。我们认为饮用水基础设施供应的一个平淡无奇且经常被忽视的方面是：清洁。我们随机分配了社区水井的看护人参加有关如何清洁水井的培训研讨会。13 到 17 个月后，由指定看护人接受培训的井的大肠杆菌污染率可以忽略不计（13 个月：2%;17 个月：4%），而对照井的大肠杆菌污染率很高（13 个月：14%;17 个月：19%）。任何大肠菌群的污染率几乎减半（13 个月：对照组 55%，治疗 30%;17 个月：对照组 77%，治疗 46%）。我们估计预防饮用水中接触大肠菌群的成本为每人 0.89 美元，如果扩大规模，用于干预的每 2376 美元可以避免一名儿童的死亡。