SUMMARY Neonatal mortality remains high in sub-Saharan Africa, where 43% of global neonatal deaths occur. In rural, low-income health facilities, contaminated drinking water and environmental hygiene conditions put newborns and their mothers at risk for healthcare-associated infections, including antibiotic resistant infections. In Kenya, health facilities are typically limited to water treatment with manual, point-of-use products that require extensive effort to use and are insufficient for the volumes of safe water required to provide quality healthcare. Our team has developed a low-cost, in-line chlorination technology, the Venturi, that automatically doses chlorine without moving parts or electricity, and is able to use chlorine produced by an off-the-shelf electrochlorinator, which can produce chlorine disinfectant solution using only water, salt, and intermittent electricity. We propose to conduct a cluster-randomized controlled trial across 30 health facilities to generate rigorous evidence on the maternal and neonatal health benefits of chlorinated water supply paired with on-site generation of chlorine for disinfection. This study combines our team’s expertise in engineering, epidemiology, microbiology, and pediatric medicine to accomplish the following aims: 1) determine the impact of the intervention on pathogenic and antibiotic resistant bacteria contamination in water supplies, high-touch surfaces, and healthcare worker hands, 2) quantify intervention effects on gut colonization of mothers and neonates by a panel of pathogenic and antibiotic resistant bacteria species linked to neonatal infection, using molecular and culture- based methods, and 3) follow up with >20,000 mother-neonate dyads to measure intervention effects on symptoms of severe bacterial infection in the first week of life. Infection prevention through effective water, sanitation, and hygiene (WASH) has been cited by national action plans as a key tool in the fight against antimicrobial resistance and, while global data show dire WASH conditions in low- and middle-income (LMIC) health facilities, there exists very little guidance for implementing effective interventions. This proposal is a time sensitive opportunity to leverage substantial philanthropic funding to deliver a novel and scalable intervention to health facilities. The overarching goal is to generate actionable evidence to inform investments in chlorination at health facilities to improve neonatal health and reduce the threat of antibiotic resistant infections.