Summary of Awards to Date

UA Ag Water app-language expansion and practical grower-inspired improvements


Jan. 1, 2018 - Dec. 31, 2018

Funding Agency

Center for Produce Safety

Amount Awarded



Channah Rock, Ph.D.
University of Arizona


Natalie Brassill, Ph.D.


Currently, growers face substantial challenges in meeting the revised FDA Food Safety Modernization Act requirements, specifically the agricultural water regulations. Over the past year, our research and extension team has received tremendous feedback on the usefulness of the Ag Water app for both the evaluation of local water quality as well as to meet the FSMA requirements (calculating Statistical Threshold Value, Geometric Mean, and die-off requirements). Whether the Ag Water app is used as a training tool to help growers and food safety managers better understand water quality or as a resource to meet the FDA FSMA regulations, updates are required to meet grower needs as well as reach the broadest stakeholder group possible (including Spanish speakers). The main objective of this proposal is to improve functionality of the Ag Water app based on real-world grower feedback, as well as, deploy a fully functioning Spanish version of the app and associated on-line tools developed by the University of Arizona.

Technical Abstract

The Produce Safety Rule (PSR) requires growers to establish a Microbial Water Quality Profile (MWQP) for each agricultural untreated surface water source. Growers must also conduct annual surveys for that water source in subsequent years (21 CFR Parts 16 and 112). The microbial water quality profile is based on the levels of generic E. coli in agricultural water. An initial MWQP must be established with a minimum of 20 water samples collected as close to harvest as possible over a period of between two to four years. Geometric mean (GM) and Statistical Threshold Value (STV) are calculated from these 20 samples (minimum) and are considered the MWQP. Several tools have been developed over the past year to compare the MWQP to the microbial water quality criteria stated in the Produce Safety Rule. These tools were developed to make it easier to calculate the GM and STV and to determine if water meets the standards for unrestricted application to produce before harvest. The tools were also designed to assist with making food safety management decisions if water does not meet the standards, including calculation of die-off requirements. While extremely useful, the initial development of these tools was restricted to English only and had not been broadly evaluated by a diversity of grower/users of the tools attempting to implement the FSMA Produce Safety Rule. The University of Arizona team will work with the original Ag Water app developer to improve the functionality of the Ag Water app based on grower feedback over the course of a one-year project. This work will be facilitated through in- person meetings and email communications on a weekly basis. Additionally, the University of Arizona has established relationships with Spanish translators and the project PI and co-PI(s) plan to utilize these resources. Once draft translations are completed, the project team will work with local grower stakeholders in Arizona, California, and Mexico to review and revise the translations to ensure appropriate word usage and word meaning. Additionally, the research team has a collated list of grower suggestions and feedback collected over the last year on the overall functionality of the app including look and feel as well as the need for improved data importing and report printing functions. After functional improvements and translations are completed to the Ag Water app and associated online tools, the project PI and team members will host a series of “open house” events to evaluate the enhanced version of the Ag Water app as well as provide additional feedback to the developer for final consideration.