Required water risk assessment can be complicated process

An agricultural water assessment required by the FSMA Produce Safety Rule for non-exempt water sources is an essential tool in postharvest handling. There are several factors to consider when approaching the process.

“It’s a risk assessment,” said Keith Schneider, professor of food safety in the University of Florida’s Food Science and Human Nutrition Department.

The assessment identifies risks where foodborne pathogens could get on the produce.

“Consider the risk and apply any mitigation that might be needed to keep any contamination from making it back to the consumer,” Schneider said.

The water source is exempt from the assessment requirement if it’s groundwater that meets FSMA’s testing and quality criteria for postharvest water. The water source is also exempt if it’s a public water system or supply that meets FSMA requirements or if the water is treated to the required standards.

An agricultural water assessment is highly subjective, with several elements influencing the process.

“How do you make an assessment?” Schneider said. “That’s the big question. “The water looks cloudy. Is that a problem? It rained, but how much rain is a problem? That’s the uncertainty that lies with FSMA.”

Crop characteristics

One of the more subjective requirements is that crop characteristics must be considered in the water assessment.

What characteristics make the produce vulnerable to contamination? How does the crop grow? For example, romaine lettuce has more risk than iceberg lettuce because water can pool inside it.

How well can bacteria adhere to the surface of the produce? Bacteria may adhere more strongly to the seedy skin of strawberries than to the waxy surface of cabbage.

Microbial pathogens can enter produce through injuries, such as physical damage from freezing or hail. Injuries can also be caused by insects or disease. How can this risk be assessed?

Seepage is another risk, affected by the porosity of the produce surface and how the crop is grown. Water can pool around crops like cantaloupe that are grown on the ground, while trellised crops or peppers have less risk. Cantaloupes also have pitted skin that may harbor bacteria.

Assessing these risks can be very difficult depending on the crop and what research exists for it, said Allissa Hern, produce safety technician with the Michigan On-Farm Produce Safety Program in Fremont, Michigan.

“Assessing crop characteristics is a requirement,” Hern said. “Make sure you can show you’re paying attention to your crop’s characteristics, even if they seem simple, and include them in your assessment.”

Guidance gaps

A lack of federal guidance makes risk assessment difficult, experts say.

“We have a little more information about crops that are frequently associated with outbreaks, but the reality is, you’re trying to make a generalization,” said Elena Rogers, North Carolina State University area specialized agent in fresh produce and food safety.

“Every farm is different, every situation is different, and risk is very farm-specific,” Rogers said. “It’s challenging when growers have to assess crop characteristics because they do not have clear guidance on how different characteristics impact the assessment and management of their agricultural water system.”

Herns agreed scarce information can be challenging.

“There’s not a lot of research on assessing the risk of crop characteristics,” Herns said. “There’s not a lot of guidance on it.”

Dan Fillius, Extension vegetable specialist at Iowa State University, said the FDA lists specific crops in examples when data is available, providing a possible starting point for risk assessment.

“You could spend a lot of time trying to make your risk assessment perfect,” Fillius said, with asking initial questions perhaps a better approach. “Ask yourself what are all of the ways water is used on the farm and what could happen? Make that your rough draft. You’ve got something written down that fits your system.”

Hern advised going back to basics and starting with the characteristics that are the easiest to assess: Is the crop grown close to the ground? What’s its surface texture? Is it prone to surface punctures or bruising?

“Talk to the food safety specialists in your area who can help you,” Hern said.

Extension staff, commodity groups and produce safety technicians can help navigate the challenging but vital process of water assessment.

“We need good research and recommendations with good science behind them,” Rogers said.