Previous investigations established that elementary and high school students residing in Reading, Massachusetts, displayed significantly higher blood pressure than their counterparts in the adjacent community of Stoneham, Massachusetts. Extensive evaluations of family history, dietary patterns, socio‐demographic variables and chemical measurements of drinking water revealed that the level of sodium in the drinking water was the variable most strongly associated with the higher blood pressure of the Reading students. A subsequent study, in which a group of Reading fifth graders’ families was given Stoneham water for all drinking and cooking purposes for a three month period., indicated that female but not male students displayed a significant decrease in their blood pressure.