Following a report to the Auvergne Regional Health Agency (ARS) by a general practitioner regarding seven cases of HEV infection between March and April 2015 among patients from the same village, an epidemiological investigation was launched to confirm the cluster nature of the cases, identify the common source of infection, and propose control measures. The investigation confirmed the spatial and temporal proximity of the 7 cases. Six cases resided in the same hamlet (3 separate households), and the 7th case regularly visited family members in that hamlet. The dates of symptom onset (or, in the absence thereof, positive test results) spanned 5 weeks. Microbiological analyses supported the hypothesis of a common source, as the five strains that could be genotyped had an identical genotype (3f) and a high degree of similarity. Investigations into the common source of contamination focused on consumption of water from the public water system. While consumption of water from the public system was the only common factor among the 7 cases, no shared meals or consumption of foods typically associated with the occurrence of HEV cases were identified. Concurrent with the exposure period, a break in the public water system at the secondary branch serving the hamlet was documented. Waterborne HEV contamination is rarely documented in developed countries. In this cluster, it appears that a private source—whose water (in which viral genome was detected) entered the public water system—was the cause of the HEV infections.