When people think about produce safety, they often picture the last steps in the supply chain—washing, cooling, and packing. The FDA’s Food Safety Modernization Act (FSMA) Produce Safety Rule flipped that perspective by regulating food safety where many risks begin: on the farm. Since it took effect in 2016, the Produce Safety Rule (PSR) has established nationwide, science-based minimum standards for the growing, harvesting, packing, and holding of covered produce. In 2024, FDA finalized a major update to one of the PSR’s most challenging areas: pre-harvest agricultural water.
This article provides a practical summary of (1) what the Produce Safety Rule covers and requires, and (2) what is different under the 2024 Agricultural Water Final Rule for pre-harvest water used on most covered produce.
A Quick Overview of the Produce Safety Rule
The PSR applies to both domestic and imported produce and is focused on reducing foodborne illness risks associated with microbial contamination. The rule does not cover every fruit and vegetable in every circumstance. It contains several key limitations and exemptions, including commodities “rarely consumed raw,” produce for personal or on-farm consumption, and produce that receives commercial processing that adequately reduces microorganisms (often described as a “kill step”), provided certain conditions and documentation are met. The rule also includes a size-based coverage threshold and a “qualified exemption” pathway (with modified requirements) for certain farms meeting specific criteria, and the qualified exemption can be withdrawn in certain public-health-driven circumstances.
The PSR’s Core Prevention Themes
First, it sets expectations for people: farms must ensure that personnel who handle covered produce or food-contact surfaces have appropriate training, and that health and hygiene practices are in place to prevent ill or infected persons (including visitors) from contaminating produce or food-contact surfaces. Handwashing timing and accessibility of facilities matter, and training and certain corrective actions must be documented.
Second, the PSR addresses the farm environment and materials. Requirements touch biological soil amendments of animal origin, with standards and approaches for treated amendments (including compost) and controls designed to reduce the risk that untreated amendments contact produce.
Third, it addresses animals. The rule takes a realistic approach—farms are not required to clear habitat or exclude animals from outdoor areas—but they must take measures reasonably necessary to identify and not harvest produce that is likely to be contaminated. At a minimum, that means visual examination of growing areas and covered produce to be harvested, regardless of harvest method.
Fourth, the PSR covers equipment, tools, and buildings. These provisions are designed to prevent contamination from unsanitary or poorly maintained infrastructure, from harvest containers to greenhouses to washing and packing areas, as well as toilet and hand-washing facilities.
Finally, sprouts receive special attention. Because sprouts grow under warm, moist, nutrient-rich conditions that can amplify pathogens, the PSR imposes additional, more prescriptive requirements for sprout operations, including environmental monitoring and batch-based testing of spent irrigation water (or in-process sprouts) for pathogens before product enters commerce.
Agricultural Water Under the Original PSR—And Why FDA Changed Course for Pre-Harvest Water
Agricultural water has always been central to the PSR. A foundational requirement remains unchanged: agricultural water used in covered activities must be safe and of adequate sanitary quality for its intended use.
Under the original 2015 framework, agricultural water requirements included microbial quality criteria and structured testing requirements for certain pre-harvest uses, particularly for water intended or likely to contact produce during growing (for example, overhead irrigation or crop sprays). Over time, FDA heard consistent feedback about the complexity and practical limitations of applying uniform testing approaches across highly diverse farms, water systems, and growing regions.
The 2024 Agricultural Water Final Rule: What Changed
The 2024 Agricultural Water Final Rule (effective July 5, 2024) revises Subpart E for “pre-harvest agricultural water” for covered produce other than sprouts when used via direct application methods. Instead of relying primarily on meeting a numeric microbial standard through routine testing, FDA moved to a systems-based agricultural water assessment model.
Under the final rule, covered farms must conduct a written, pre-harvest agricultural water assessment that evaluates factors tied to contamination risk, including the nature of the water source and distribution system, the degree of protection from contamination (including impacts from animals and adjacent/nearby land uses), water application practices, crop characteristics (including susceptibility to surface adhesion or internalization), and environmental conditions like heavy rain or extreme weather. The assessment is not a one-time exercise: farms must reassess at least annually when they apply pre-harvest agricultural water to covered produce, and also when significant changes occur that could affect hazard introduction.
Corrective Measures Versus Mitigation Measures
The 2024 rule distinguishes between two types of required actions based on assessment outcomes: corrective measures and mitigation measures. Understanding when each applies is critical for compliance.
Corrective measures apply when a farm determines that its pre-harvest agricultural water is not safe or is not of adequate sanitary quality for its intended use. This represents the most serious finding—one requiring immediate action to protect public health. Farms must immediately discontinue use of the water and implement corrective measures before resuming use. Options for corrective measures include: (1) re-inspecting the entire affected agricultural water system under the farm’s control and making necessary changes, then taking adequate measures to verify the changes were effective; or (2) treating the water in accordance with Produce Safety Rule standards for treatment effectiveness, delivery, and monitoring.
Mitigation measures, by contrast, provide more flexibility in timing. They apply when the assessment identifies conditions that are reasonably likely to introduce known or reasonably foreseeable hazards, but the water has not yet been determined to be unsafe. The required timing for mitigation measures depends on the nature of the hazard. For hazards related to animal activity, biological soil amendments of animal origin, or untreated or improperly treated human waste on adjacent or nearby lands, mitigation measures must be implemented promptly—and no later than the same growing season as the assessment. For all other hazards, mitigation measures must be implemented as soon as practicable and no later than one year after the date of the assessment.
The range of available mitigation measures is broader than for corrective measures and includes: making necessary changes such as repairs; increasing the time interval between last direct application of agricultural water and harvest to allow for microbial die-off (with scientifically valid supporting data); increasing the time interval between harvest and the end of storage; changing the water application method to reduce the likelihood of produce contamination; treating the water; or taking an alternative mitigation measure supported by scientific data and information. Farms are not required to notify or seek FDA approval for alternative mitigation measures.
Importantly, if a farm fails to implement mitigation measures within the required timeframe, or determines that its mitigation measures are not effective, it must discontinue use of the agricultural water until it has implemented adequate measures to reduce the potential for contamination.
When Reassessment Is Required
Farms must conduct an agricultural water assessment at least once annually when they apply pre-harvest agricultural water to covered produce (other than sprouts). Beyond this baseline requirement, a reassessment is required whenever a significant change occurs in the farm’s agricultural water system, water use practices, crop characteristics, environmental conditions, or other relevant factors that make it reasonably likely a hazard will be introduced into or onto covered produce or food contact surfaces.
Examples of significant changes that trigger reassessment include: a change from an untreated ground water source to an untreated surface water source; installation of a new water distribution system; new uses of adjacent or nearby land (such as a new dairy production operation); changes in agricultural water practices including the method or timing of water application; growing a different type of covered produce than previously grown; and unanticipated environmental events not already addressed in the assessment, such as unexpected flooding or an earthquake that may affect piped distribution systems.
When conducting a reassessment, farms must evaluate the impacts of the change on the assessment factors, identify any new hazards, and make a written determination as to whether corrective or mitigation measures are reasonably necessary. Farms that routinely switch water sources or make other predictable changes may account for such activities in their annual assessment rather than conducting separate reassessments each time, provided the assessment accurately describes and evaluates each water system and practice.
Mitigation Measures for Adjacent and Nearby Land Use Hazards
When a farm’s agricultural water assessment identifies that adjacent or nearby land use is reasonably likely to introduce known or reasonably foreseeable hazards related to animal activity, biological soil amendments of animal origin, or the presence of untreated or improperly treated human waste, the 2024 rule requires expedited action. Mitigation measures must be implemented promptly—and no later than the same growing season as the assessment or reassessment. This accelerated timeline reflects FDA’s recognition that several produce-related outbreaks have been linked to contamination originating from adjacent and nearby land uses.
Farms have flexibility in choosing appropriate mitigation measures. Options include: making necessary changes such as repairs (for example, building a berm to reduce runoff, installing a windbreak, or repairing a well-head); increasing the time interval between the last direct application of agricultural water and harvest to allow for microbial die-off (supported by scientifically valid data); increasing the time interval between harvest and the end of storage; changing the water application method to reduce the likelihood of produce contamination (such as switching from overhead spray to subsurface drip irrigation); treating the water in accordance with Produce Safety Rule standards; or implementing alternative mitigation measures supported by scientific data and information.
Importantly, farms are not required to mitigate hazards at the location where they originate, nor are they expected to take action against neighboring entities. Instead, farms must assess potential impacts from adjacent and nearby land uses on their agricultural water quality and implement measures within the farm’s control to reduce contamination risk. Even when the source of hazards is outside a farm’s control, the farm can take steps such as diverting runoff away from its water system or changing its water application method. If mitigation measures prove ineffective, the farm must discontinue use of the agricultural water until adequate measures are implemented.
Why This Matters for Farms and Supply Chains
From a compliance standpoint, the 2024 rule is both more tailored and more documentation-driven. Farms will need to be ready to explain their water system, their risks, and their decisions—not just produce a set of lab results. For buyers and supply-chain partners, the shift reinforces a broader trend in food safety regulation: outcomes depend on whether a farm has a credible, risk-based system that is implemented and recorded, not simply whether a test result was filed away.
