'Ag Water' App Assists Growers on Food Safety Issues
The newly developed app, the result of a collaboration involving the UA, makes it easier to determine whether a water source is safe from a public health standpoint to use on produce.

UA College of Agriculture and Life Sciences
Aug. 3, 2016

Funded by the California-based Center for Produce Safety, Ag Water is the first app of its kind, designed by University of Arizona researchers and their partners to help growers meet nationwide mandates for product safety.

Created in collaboration between research faculty and staff at the UA and University of California, Davis, in partnership with UA Mobile Matters, the app can be used on any mobile device that receives a Wi-Fi connection. That includes mobile phones, tablet devices, laptops and desktops, and it is currently available for download in iTunes and Google Play stores. 

In December 2015, the Food and Drug Administration released the final version of the Food Safety Modernization Act, which includes information on the modified Produce Safety Rule, or PSR. The rule is a set of national regulations that growers must follow to maintain compliance with water quality, soil and other agricultural and produce-related food safety concerns. 

The water-quality portion of the rule requires that growers test their water sources regularly and make complex calculations for geomean and statistical threshold value to determine whether a water source is safe from a public health standpoint to use on produce.  

"This task can be mundane and time-consuming for the busy farmer, so the research and development team designed the Ag Water app as a tool that growers can use to input lab values from sampled water and simply click 'calculate' to determine if they are compliant with the Food Safety Modernization Act PSR," said Dametreea Carr, assistant health educator in the UA Cooperative Extension Water Quality Program at the Maricopa Agricultural Center.

Carr, also a graduate student in public health, directed the design of the app with stakeholders in mind. Channah Rock, water quality specialist and professor in the UA Department of Soil, Water and Environmental Science in the College of Agriculture and Life Sciences, is the principal investigator on the project.

In addition to a simple, yes-or-no response, the app also offers advice stating how many days of bacterial die-off are needed before a water source can be used or retested. 

One of the main features is that Ag Water has the ability to predict the quality of a water source in real time. To accomplish this, the app utilizes location, historical water quality data, and weather information from the UA College of Agriculture and Life Sciences' Arizona Meteorological Network, or AZMET, stations in Yuma, Arizona, and across the state that are then fed into a quantitative microbial risk assessment model developed by UA faculty. 

For the most accurate results, the app even allows users to input physical parameters (such as water temperature, electrical conductivity and dissolved oxygen) that can be used to strengthen the confidence of the final water quality prediction.  

The geomean and statistical threshold value calculator functions of Ag Water have been designed for national use and will meet a need within the agriculture industry.

"Ag Water fills a critical need for growers by providing a tool that they can use to make informed decisions about their water resources that ultimately support food safety and protect public health," Rock said. "As faculty within Cooperative Extension, our programs strive to use scientific-based research to support stakeholder needs where traditional research stops. This app fills that gap and is just one example of the critical work that we do to support our clientele."

Ag Water is user-friendly, including step-by-step instructions if needed and allowing users to save or delete information as they see fit.  Each user profile is private, and no information is ever collected for use by those other than the registered user.

The app was unveiled at the Center for Produce Safety 2016 Research Symposium in June, aimed to provide and share ready-to-use, science-based solutions to prevent or minimize produce safety vulnerabilities.

"Ag Water was designed for the agriculture industry and has received overwhelmingly positive responses from stakeholders during test-play at agriculture conferences, meetings and workshops across the nation," Carr said.

"I do have to say it has helped us out a lot," said Kaley Grimland-Mendoza, enterprise development specialist with ALBA Organics in Salinas, California. "In fact, on a new food-safety audit we had, it helped us to provide correct information to the auditor. He was looking for a water risk baseline, based on historic water quality data that takes into account the crop, crop stage and irrigation method."

Jacqueline Gordon Nunez, director of education for the Washington State Fruit Tree Association, said the app "will be incredibly important for the Pacific Northwest tree fruit growers by helping them develop their individual Microbial Water Quality Profile. It will also help growers understand how their results compare to the criteria for agricultural water quality outlined in the Produce Safety Rule.

"In addition, the app will also determine if a delay interval after watering is needed," Nunez said, "and will automatically calculate the required interval before harvest. This is critical information for the growers, and greatly simplifies compliance with the Food Safety Modernization Act requirements."

Extra info

A web-based version of the app can be accessed online. The Ag Water development team includes:

  • Channah Rock, University of Arizona, as the principal investigator
  • Dametreea Carr, a UA Master's in Public Health student, for app design and content
  • Collaborators Akrum Tamimi, Kelly Bright and Charles Gerba of the UA Department of Soil, Water and Environmental Sciences in the College of Agriculture and Life Sciences
  • Linda Harris and Rupinder Mashiana with the University of California, Davis, Western Center for Food Safety
  • App developers Gregory Buczek, an independent contractor, and the UA's University Information Technology Services Mobile Services
  • The Center for Produce Safety, providing funding


Resources for the media

Channah Rock 

UA College of Agriculture and Life Sciences