Depuration or the process of self-purification has been used for many years to reduce the enteric microbial contaminants from shellfish harvested from sewage polluted waters. Little is known however about the effectiveness of this process in eliminating enteric viral pathogens. This study compared the reduction of hepatitis A virus (HAV) to that of poliovirus 1, bacteriophage MS2, Escherichia coli, and Streptococcus faecalis, from experimentally contaminated clams (Mercenaria mercenaria). The clams were subjected standard depuration conditions in a model, laboratory-scale system. The effect of temperature (12, 18, 25°C) and salinity (8, 18, 28ppt) on virus and bacteria depuration over period of 4-5 days was studied. The viruses were not depurated as effectively as the bacteria. Elimination rates of test organisms was independent of temperature. Depuration rates were reduced at lower salinity (8 and 18ppt). The results indicate that the current the practices and conditions of depuration are ineffective in eliminating enteric viruses from clams. These studies further suggest that coliform bacteria is an inadequate indicator of virus elimination from shellfish.