This document provides guidance for implementing household-based water treatment and safe storage projects in developing countries. It outlines 12 steps to plan and carry out a Safe Water System project, including gathering background data, setting objectives, writing a proposal, assembling a team, deciding on products and distribution methods, planning behavior change strategies, monitoring and evaluation, and project implementation. The Safe Water System is an approach that employs simple, inexpensive technologies like sodium hypochlorite solution and safe water storage containers to improve water quality at the household level through point-of-use water treatment and behavior change activities.