The microbial quality of irrigation water used in edible crop production has been the object of increasing scrutiny. However, the actual risk of pathogen contamination posed by irrigation water, as well as the relative risk compared to other factors, are not well understood or quantified.

This symposium aims to critically assess available evidence on the role of microbial irrigation water quality in (a) introducing pathogens into produce fields and (b) directly contaminating produce units. The symposium will address the wider context of other contamination and cross-contamination processes that may occur in the field and are affected by water (e.g., splashes of animal feces), but will focus on the fate and relative importance of pathogens occurring in source waters or distribution systems. Goals of the symposium include presenting or addressing: (1) a summary of available data on microbial quality, in particular bacterial and viral, of irrigation waters in the U.S. (at sources, at the point of delivery, and evidence of direct water-produce transfer), including data gaps that hinder the development of effective management standards; (2) the distinction between direct and indirect role of irrigation water in introducing and spreading pathogens onto the field, and the relationship between irrigation and other processes affecting pathogen ecology (e.g., conditions for bacterial growth or survival). The latter will not be the focus of this symposium, but needs mentioning; (3) a quantitative risk-based framework for assessing the impact of irrigation water quality on the likelihood and extent of produce contamination; and (4) feasibility and constraints of potential risk-based regulatory and management approaches.

Presentations