EPA Method 1615 measures enteroviruses and noroviruses present in environmental and drinking waters. The viral ribonucleic acid (RNA) from water sample concentrates is extracted and tested for enterovirus and norovirus RNA using reverse transcription-quantitative PCR (RT-qPCR). Virus concentrations for the molecular assay are calculated in terms of genomic copies of viral RNA per liter based upon a standard curve. The method uses a number of quality controls to increase data quality and to reduce interlaboratory and intralaboratory variation. The method has been evaluated by examining virus recovery from ground and reagent grade waters seeded with poliovirus type 3 and murine norovirus as a surrogate for human noroviruses. Mean poliovirus recoveries were 20% in groundwaters and 44% in reagent grade water. Mean murine norovirus recoveries with the RT-qPCR assay were 31% in groundwaters and 4% in reagent grade water. This dataset is associated with the following publication: Fout , S., J. Cashdollar , S. Griffin , N. Brinkman , E. Varughese , and S. Parshionikar. EPA Method 1615. Measurement of Enterovirus and Norovirus Occurrence in Water by Culture and RT-qPCR. Part III. Virus Detection by RT-qPCR. Journal of Visualized Experiments. JoVE, Somerville, MA, USA, 107: e52646, (2016).