This data release describes water service areas (WSA) for community water systems (CWS) within the conterminous United States, representing areas of active service between 2010 and 2020. A WSA is defined by a delineated polygon that contains all customers served by a water system. WSAs are represented by an ArcGIS shapefile. The U.S. Safe Drinking Water Act defines a CWS as a type of public-water system that serves at least 15 service connections used by year-round residents or regularly serves at least 25 year-round residents. Water may be used for several purposes (such as for commercial, industrial, and residential uses) or may be used only for one specific purpose (such as for residential use). This data release includes CWS that operate their own infrastructure and furnish water through their own water sources, purchase water from a neighboring water system, or are diversified in that they serve water from a combination of their own sources and purchases. This dataset also includes communities that do not operate a water system but receive water services by way of contract; in other words, an adjacent water system’s infrastructure extends their waterlines across boundaries from which residents connect to, are supplied, and directly billed from this neighboring water system.