Publisher Summary Water is a common vehicle for the transmission of many enteric viruses. Enteric viruses survive longer in fresh and marine water than coliform bacteria, which are used to monitor water quality. In marine and other surface waters, numbers of enteric viruses are often too low to be detected in unconcentrated samples. Therefore, large volumes of water must be concentrated by adsorption/filtration and elution (desorption) before analysis. More than 100 types of human pathogenic viruses are present in fecally contaminated water, and are detected by the current available methods. The detection of adenoviruses, hepatitis A virus, astroviruses, and rotaviruses by cell culture is possible; however, the methods are tedious and less often used. Nucleic acid hybridization and the polymerase chain reaction (PCR) are used for detecting human viruses and other fastidious microbial pathogens in the environment. Molecular detection methods are important in studying the occurrence of Hepatitis A and Norwalk-like viruses, which are epidemiologically important pathogens but do not produce cytopathogenic effects (CPE) readily in cell culture. Molecular techniques have also enhanced the speed and sensitivity of detection for the more routinely cultured enteroviruses.