Rural communities in emerging countries are historically excluded from public sanitation policies, which adds to their vulnerability, especially in relation to health. This study evaluates the health effects of sanitation in two rural communities (intervention and control) through a study of epidemiology and hygiene. Analysis of the two communities before and after the intervention indicates a considerable increase in water consumption in liters/household.month, a decrease in the prevalence of diarrhoea in the intervention community and a reduction on the proportion of children below the reference value for the z-score in the intervention community. This study demonstrated that the water supply system can modify the uses of water by increasing the amount of water spent in personal and domestic hygiene activities, and that reducing intermittence of service, improving water quality for consumption, and increasing domestic consumption of water minimize health risks in the short term. This issue has been published as Volume 4, Number 5 of the WATERLAT-GOBACIT Working Papers (http://waterlat.org/publications/working-papers-series/). It corresponds to the Student Prize Series of the WATERLAT-GOBACIT Network’s Working Papers. This is a special series of the Working Papers, dedicated to the doctoral and master dissertations submitted to the annual competition organized by the Network to reward the best work submitted in both categories (for additional information visit the web page of the Student Prize: http://waterlat.org/waterlat-student-prize/). This is the third issue of the Student Prize Series. It features two articles based on two doctoral dissertations submitted to the 2016 Student Prize Competition. These were doctoral and master dissertations successfully defended in universities from Spain and Brazil.