The human enteric viruses have common characteristics of being faecally excreted and hence, they can easily get into sewage and waters. Many human enteric viruses have been found in sewage, surface water, ground water and sea water. Some enteric viruses can persist for a long time in the environment. Reported survival time of them ranges from 2 to 168 days in tap water, 25 to 125 days in soil, 2 to 130 days in sea water, 2 to 168 days in river water, 6 to 90 days in oysters, and 8 to 20 days in marine sedim...