Earlier this year, the FDA issued a final rule related to the preharvest agricultural water requirements for covered produce stipulated in the Food Safety Modernization Act Produce Safety Rule.

The Produce Safety Rule (PSR) sets the minimum regulatory standards to ensure that normally eaten raw fruits and vegetables are safe for human consumption. The main purpose of the PSR is to prevent microbiological contamination of produce coming from farms. The rule sets standards for growing, harvesting, packing and holding produce for human consumption. Agricultural water is one of the major components of the PSR. Contact your local extension center if you are interested in attending a produce safety training.

The rule makes a distinction between water used to grow the crops (preharvest water) and the water used during harvesting and postharvest activities (postharvest water). This article focuses on the final ruling made by the FDA on preharvest water. The postharvest water requirements of the rule remain unchanged.

What changed for the preharvest water requirements?

Initially, the PSR required growers to build a water-quality profile by testing their water source as part of their risk assessment and management requirements. The final rule replaces the microbial water-quality profile requirements with a systems-based assessment to identify hazards and managing risks related to preharvest agricultural water. Although the water-quality profile is no longer needed, testing can still be used as a tool when building the assessment and mitigation plan.

Through the agricultural water assessment, growers must provide documentation (evidence) that they identified conditions that can introduce known or foreseeable hazards and which corrective/mitigation measures must be taken to minimize risks of using preharvest water. There are two components to the agricultural water assessment: 1) An evaluation of the known and foreseeable risks, and 2) The risk correction/mitigation strategies based on the outcomes of the evaluation.

How do I make a preharvest agricultural water assessment?

FDA has an online tool that growers can use to build their agricultural water assessment at https://agwaterassessment.fda.gov. Alternatively, you can use the following guide to build your preharvest agricultural water assessment.

Part 1: Risk evaluation

1.1. Evaluating the agricultural water system: This assessment will generate outcomes that will inform the mitigation and corrective strategies suitable for your farm.

• Water source: Are you using surface or groundwater? If you’ve taken the PSR training, you know that surface water tends to have higher risk of contamination than groundwater and municipal water sources. Groundwater sources can become contaminated if wells are not installed and maintained properly.
• Irrigation water distribution system: Did you inspect your irrigation system? Check for any leaks that may be a source of contamination. Also, municipal or groundwater becomes surface water if you are holding them in open containers/tanks.
• Potential sources of contamination to your water source and distribution system: Did you observe any sources of contamination in the vicinity of your water source and distribution system? Examples could include animals (wild and domesticated), neighboring farms and storage of biological soil amendments of animal origins, among others.

1.2. Evaluating the agricultural water management practices

• Irrigation method: Is the irrigation system exposing the edible portions of the plants to contaminated water? Localized irrigation systems, such as drip irrigation, have lower risks compared to overhead irrigation systems. For example, you can safely use pond water to irrigate tomato crops if you use drip irrigation and provide evidence that the driplines are in good condition. You can still use overhead irrigation, but you need to demonstrate that the water is safe or poses no risk to human health, or that you waited some time to elapse between irrigation and harvest.
• Application interval: Microbes that land on a surface can die over time due to solar radiation or desiccation. Microbial die-off period is a mitigation strategy, not a corrective strategy, meaning that it is only an option if the outcome from the previous evaluation indicates that the water is safe. You must first mitigate any conditions that lead to water contamination prior to implementing microbial die-off as a mitigation strategy.

1.3. Crop characteristics: Some crops have higher risks of contamination than others because of plant growth habits, produce surface characteristics or incidence of cracks and bruises. For example, a strawberry crop will have higher risk than a blueberry crop because it has a creeping growth habit as opposed to a bush. Another example is that cracked tomatoes have wounds were pathogens can get into the fruit.

1.4. Environmental conditions and other factors: Identify and record any other risk that my impact the preharvest agricultural water. Is your farm in a flood zone? Did you notice wildlife activity near your irrigation pond? dD neighbors have access for recreational activities in your pond?

Part 2: Outcomes-based corrective and mitigation strategies

Determine if corrective or mitigation strategies are necessary to reduce the risks for potential contamination that were identified in Part 1. Every farm is different and will deal with a variety of risks, so it is difficult to summarize mitigation strategies in this guide. Please contact your local extension agent if you need assistance when developing and implementing corrective or mitigation strategies.

It is required that you regularly inspect and adequately maintain your water system at least once a year. We recommend that you update your preharvest agricultural water system assessment every year and when you make changes to your water management practices (such as using corrective or mitigation strategies).

Exemptions

Farmers can be exempt from conducting a preharvest agricultural water assessment if they provide records and evidence that:

• The preharvest agricultural water meets the requirements that apply for harvest and postharvest agricultural water of no detectable E. coli. This includes not using untreated surface water.
  • A grower can implement a water treatment system and keep records of water test reports that demonstrate that the treated water meets the harvest and postharvest agricultural water requirements. The grower keeps additional records to demonstrate that the water treatment technology is effective, such as the concentration of active ingredient according to product label, contact time and other water-quality parameters that may impact the efficacy of the treatment technology. For example, the optimum pH for chlorine is between 6.5 and 7, therefore a grower using chlorine treatment should keep records of the pH of the water.
  • A grower uses water from a public supply and the grower has records from the supplier demonstrating that the water meets the harvest and postharvest agricultural water requirements.
• It is reasonably likely that any management practices made on water that meets the harvest and postharvest agricultural water requirement will not change the quality of the water prior to it being used as agricultural water.  Growers may have systems in place to store and move water that can introduce risks of contamination. For example, a hydroponic farm that uses municipal water to grow lettuce using a deep-water culture (floating raft on a pond) is not exempt. The use of open ponds introduces risks that cannot guarantee that the quality of the municipal water will remain intact.

What is the deadline to comply with the agricultural water rule?

• Preharvest water
  • Large farms (average annual monetary value of produce sold during the previous three years is more than $500,000): April 7, 2025.
  • Small farms (average annual monetary value of produce sold during the previous three years is between $250,000 and $500,00): April 6, 2026.
  • Very small farms (average annual monetary value of produce sold during the previous three years is between $25,000 and $250,000): April 5, 2027.
• Harvest and postharvest water
  • Large farms: Jan. 26, 2023.
  • Small farms: Jan. 26, 2024.
  • Very small farms: Jan. 26, 2025.

Contact your local extension center if you have any questions regarding produce safety. You can also write us at:

Juan Cabrera-Garcia
110 Waters Hall
University of Missouri
Columbia, MO 65211