In July-September 2023, an outbreak of E. coli O157:H7 illnesses occurred among children in Utah. Local, state, and federal public health partners investigating the illnesses linked the illnesses to untreated, pressurized, municipal irrigation water (UPMIW). Thirteen outbreak associated cases were identified. Seven cases were hospitalized. No one died. Two of the children hospitalized developed hemolytic uremic syndrome (HUS).

Twelve of 13 ill children reported playing in or drinking UPMIW. Microbial source tracking, a method to indicate possible contamination sources, identified birds and ruminants as potential sources of fecal contamination of the water.