Water is one of the most likely vehicles to bring pathogens in direct contact with fresh produce.
Here are some practical ways to reduce contamination with water:

• Be familiar with the seasonal quality of any surface water source used for gardening. Surface water can include water from ponds, lakes, streams, and any other water source that is directly exposed to the environment.

• Carefully review all uses of graywater (wastewater from baths, showers, clothes washers, and bathroom sinks) for irrigation of edible garden plants. Do not use any water that could contain pathogens.

• Ensure that home wells are designed and maintained to prevent contamination of the water from surface run-off or soil infiltration.

• Irrigation methods that minimize contact between the water and the edible parts of the plant (i.e., drip irrigation) reduce the potential for contamination.

Pathogen-free potable water, equal in quality to water from a municipal water system, should be used for:

• Any foliar (leaf surface) applications
• Cleaning fresh produce after harvest

Courtesy of UC Davis