States, territories, and tribes take water samples to monitor the water at swimming beaches to see if levels of specific indicator bacteria (e.g., enterococci) exceed the water quality standards that apply to that water. "Program beaches" have, at minimum, a program to notify the public if swimming in the coastal water is unsafe, and most also have a program to routinely monitor the water quality. In 2023, 70 percent of coastal and Great Lakes program beaches in the United States were monitored for pathogens or pathogen indicators. Chart 1 shows the number of beaches that were monitored and number of program beaches in each state, territory, and tribe in 2023. When monitoring results show exceedances for pathogens or pathogen indicators, states, territories, and tribes either issue a beach advisory that warns people of possible risks of swimming or a beach closing that closes the beach to public swimming. The states and local agencies that do not routinely monitor water quality use models or policies (e.g., advisory after a certain amount of rainfall) as a basis for issuing notification actions at beaches. These advisories or closures typically stay in effect until monitoring shows that levels of pathogens or pathogen indicators comply with applicable water quality standards.