This is the first study I’ve seen that looked at the benefits of rural water availability with regard to educational benefits.
Jing Zhang, Lixin Colin Xu. The long-run effects of treated water on education: The rural drinking water program in China. Journal of Development Economics Volume 122, September 2016, Pages 1–15.
Since little is known about the long-run effect of treated water, we examine the educational benefit to rural youth in China from a major water treatment program started in the 1980s. By employing a data set covering two decades and encompassing more than 4700 individuals between ages 18 and 25, we find that, on average, the program increased the completed grades of education of rural youth by 1.1 years. Moreover, the effect was highly heterogeneous across gender and age of exposure. Rural girls benefited from water treatment more than rural boys such that the water treatment program completely eliminated the gender gap in education in treated villages. Young rural people with access to treated water in early childhood experienced significantly higher gains in schooling attainment (i.e., by more than a year) than those that gained access at later stages of life. Our analysis suggests that this program was cost-effective.