Seasonal and short-term temporal variations of radon suggest that one-time sampling of water supplies may not produce a representative sample of well water. Obtaining concentration levels of water supplies at or near the proposed U.S. EPA Maximum Contaminant Level is complicated by these variations. The aims of this research are to determine temporal variations in ²²²Radon in community water supplies looking specifically at water use, temperature, precipitation, and barometric pressure; determine the relationship between raw and finished water ²²²Radon concentrations over time in water supplies where ²²²Radon in finished water exceeds that in raw water; and propose a sampling scheme which will provide a representative ²²²Radon water concentration.