Earlier this year the FDA issued a final rule related to the pre-harvest agricultural water requirements for covered produce stipulated in the Food Safety Modernization Act (FSMA) Produce Safety Rule. For those unaware, 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. Please contact your local extension agent if you are interested in attending a produce safety training.

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

What changed for the pre-harvest 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 pre-harvest 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 pre-harvest water. There are two components to the agricultural water assessment, first is an evaluation of the known and foreseeable risks and second are the risk correction/ mitigation strategies based on the outcomes of the evaluation.

How do I make a pre-harvest 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 become 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, 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. However, you can still use overhead irrigation, but you need to demonstrate that the water is safe or pose no risk to human health, or you waited some time to lapse 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 indicate 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 Envrionmental conditions and other factors: identify and record any other risk that my impact the pre-harvest agricultural water. Is your farm in a flood zone, did you notice wildlife activity near your irrigation pond, do 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 pre-harvest 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 pre-harvest agricultural water assessment if they provide records and evidence of:

• The pre-harvest agricultural water meets the requirements that apply for harvest and post-harvest agricultural water of no detectable E. coli. This includes not using untreated surface water.
  • A grower can implement a water treatment system and keeps records of water test reports that demonstrate that the treated water meets the harvest and post-harvest agricultural water requirements. The grower keeps additional records to demonstrate that the water treatment technology es 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 post-harvest agricultural water requirements.
• It is reasonably likely that any management practices made on water that meets the harvest and post-harvest agricultural water requirement will not change the quality of the water prior to 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?

• Pre-harvest water
  • Large farms (average annual monetary value of produce sold during the previous 3 years is more than $500,000): April 7th, 2025
  • Smal farms (average annual monetary value of produce sold during the previous 3 years is between $250,000 and $500,00): April 6th, 2026
  • Very small farms (average annual monetary value of produce sold during the previous 3 years is between $25,000 and $250,000): April 5th, 2027
• Harvest and post-harvest water
  • Large farms: January 26th, 2023
  • Smal farms: January 26th, 2024
  • Very small farms: January 26th, 2025

Please reach out to your local extension agent if you have any questions regarding produce safety. You can also send us a letter to: