Guaranteeing access to safe drinking water is still a challenge in rural households in developing countries, and unsafe water sources are responsible for millions of deaths each year around the world. Coupons for free dilute chlorine solution are (i) a cost-effective solution to targeting water treatment for households that need it and will use it and (ii) an effective way of ameliorating child health and reducing diarrhea incidence. It is still an empirical challenge, however, to see if the positive health effects will be maintained when the program is implemented at scale. In this study, we conduct a randomized controlled trial (RCT) to study the impacts of a chlorine coupon program implemented at health clinics on child health, including self-reported diarrhea, fever, and cough incidence in the previous two weeks. We further investigate the pathway of the impact, such as self-reported and objectively measured use of chlorine and frequency of visits to health clinics. We monitor the program's impact at Health and Demographic Surveillance Systems (HDSS) sites in collaboration with the Kenya Medical Research Institute (KEMRI). We collect similar household data in the study areas outside the HDSS site to monitor the program's impact. Data collection includes child mortality, as well as verbal autopsies for deceased children. Data on mortality will be useful for future meta-analyses that pool data from multiple studies in order to estimate the mortality impact of free chlorine distribution schemes.