There are about 20,000 wastewater treatment plants in the United States. These plants discharge about 50 trillion gallons of wastewater daily into the nation’s surface waters (Dorfman, 2004). Most wastewater contains human feces, which are a potential source of microbial pathogens. Pathogens that may be found in the sewage include bacteria, viruses, and protozoa. Table 1 lists some of the pathogens that have been isolated from wastewaters. All of these microorganisms are transmitted via the fecal-oral route; therefore, if wastewater is discharged to surface waters, they pose a health risk to anyone who comes in contact with the water or who consumes food harvested from the water. The potential risks that are associated with wastewater make disposal and control of wastewater a significant public health issue.