The closures and advisories affect swimmers and beachgoers across multiple states, particularly in areas with aging sewer systems that discharge untreated sewage during storms. Contaminated water poses significant health risks, including nausea, vomiting, diarrhea, and skin infections from enterococci exposure. E. coli poisoning can result in severe abdominal cramps, bloody diarrhea, and, in extreme cases, kidney failure, especially in young children. These conditions highlight the importance of adhering to public health advisories to prevent illness.