Water Quality

Water has always played a key role as a vehicle for the transmission of pathogens transmitted by the fecal-oral route. Several produce outbreaks have been known or suspected to have arisen from contamination in the field, suggesting contamination by irrigation or during handling. The microbial quality of irrigation water depends on the source of the water and contamination as it is transmitted through the distribution system. Contamination of produce may also occur through the use of contaminated water to apply pesticides, fertilizers, washing, hydrocooling, handwashing, and icing. It has been observed that use of contaminated hand wash water, resulting from multiple use by different individuals, can result in hand contamination by enteric bacteria. Furthermore, use of fecally contaminated water for application of pesticides or in wash water may lead to produce contamination. Although the percentage of pathogen transfer from contaminated water to produce by some types of irrigation methods (e.g., drip irrigation) may be low, risks can still be considered significant because of the low numbers of some enteric pathogens, such as viruses, necessary to cause infection. Meaningful standards for indicator bacteria that better assess the risk of produce contamination and risk of infection to the consumer need to be developed.