Groundwater of the United States may be subjected to fecal contamination from avariety of sources. The objective of this analysis was to address seasonal trendsand to examine whether there was any relationship between PCR and culturablemethods in different temperature groups. Groundwater samples were collected from448 sites (wells) in 35 states. Of the 448 sites, 25 were sampled more thanonce. Each sample was assayed for virus infectivity using a cell culture assay,the presence of virus nucleic acid using RT-PCR, bacteriophage using threedifferent bacteria hosts, total coliforms, enterococci, Clostridium perfringens,total organic carbon, various minerals, and metals. Includes 11 references, table, figures.