How does food and water become contaminated with hepatitis a?

Poor sanitation. Hepatitis a is transmitted , due to not washing the hands aftenruse of toilet, unsanitary food handling, bad sewage disposal and contamination to agricultural produce .
Fecal contamination. If there is fecal contamination of the water and/or soil, it can transmit hepatitis a to unsuspecting people.
With feces... It's a gross answer...But hepatitis a is transmitted through the fecal-oral route, that is by contamination of food and water by feces.