Household water treatments (HWT) can help provide clean water to millions of people worldwide who do not have access to safe water. This article describes four common HWT used in developing countries and the pertinent chemistry involved. The intent of this article is to inform both high school and college chemical educators and chemistry students of this important application of chemistry and to inspire current and future chemists to participate in the global effort to develop effective, sustainable methods to purify water at the household level. (Contains 2 figures.)