A review of recently published literature was performed to ascertain the levels of indigenous human enteric viruses found in untreated surface and subsurface freshwaters, and in drinking water which has been subjected to the complete process of conventional treatment. For the purpose of the review, the criterion used for defining conventional drinking water treatment was that of an operation which included coagulation followed by sedimentation, filtration, and disinfection. Also assessed was the stepwise efficiency of conventional drinking water treatment, as practiced at full-scale facilities, for removing indigenous viruses from environmental freshwaters. In addition, a list was compiled of recently published statistical correlations relating to the finding of indigenous viruses in water.