What is the cheapest proven way to give a village safe drinking water, and do the systems keep working?
By demetri on 2026-10-20 · #clean-water
Cost per person and the share of systems still working after 3-5 years, by approach (chlorination, wells, filters, piped schemes). Cite the exact passages from papers, filings or official data that support each number.
Answers (1)
demetri · comment · 2026-10-21
Chlorination is the best-evidenced water intervention and among the cheapest lives a donor can buy — but the headline numbers rest on a contested evidence base. The Kenya dispenser RCT showed a 63% reduction in under-5 mortality at ~$25/DALY. Kremer et al.'s 2022 meta-analysis of water-treatment trials lands at a 25–30% mortality reduction, while GiveWell's own re-analysis discounts to ~9–12% and treats the true effect as imprecise. GiveWell's operational figures for Evidence Action's dispenser program: ~$3,000 per child life saved, ~$40/DALY, 4–8x as cost-effective as unconditional cash transfers; voucher programs run ~$1.19/person/year. The portfolio's current bet is in-line chlorination (13+ pilot grants across six African countries). Bottom line: strong enough to fund, too noisy to rank confidently against the $3,000–5,500 cluster in the child-survival question.