As a regulation that set new definitions for farms and science-based safety standards for the growing, harvesting, packing, and holding of produce—both domestic and imported, the provisions of the Produce Safety Rule are, by necessity, quite in-depth and complex. As such, my goal in this Legislative Update is to provide insights and compliance assistance for the main provision of the rule: the Agricultural Water Requirements (Subpart E).

The overarching mandate of the requirements for agricultural water quality is that it be safe and sanitary. As such, farms are required to inspect all agricultural water systems at least once a year to identify conditions that are reasonably likely to introduce hazards considering the nature of the source. All water system equipment and sources also must be adequately maintained, inspected, and stored to prevent hazards; action taken to correct any significant deficiencies; and the source kept free of debris, trash, domesticated animals, and other possible contamination. Farms are to implement measures to reduce the potential for contamination from pooled water.

In determining a treatment method for agricultural water, the farm must use a method and delivery that will ensure the water is safe and sanitary and/or meets the relevant microbial quality criteria, and it must be regularly monitored for this.

MICROBIAL QUALITY CRITERIA. This also sets criteria for microbial quality, with no detectable generic Escherichia coli (E. coli) allowed in 100 milliliters of agricultural water or any untreated surface water. The limit applies to sprout irrigation, handwashing, or any direct contact of covered produce during or after harvest. For water that is directly applied to growing produce (other than sprouts), microbial quality criteria are based on the geometric mean (GM) of samples being 126 or less CFU of generic  E. coli  per 100 milliliters of water and the statistical threshold (STV) of samples as 410 CFU or less in 100 milliliters. (The GM is, essentially, the average amount of generic  E. coli  in a water source; STV reflects the amount of variability in the water quality.)

If the agricultural water is found or believed to not be safe or of adequate sanitary quality, use must be immediately discontinued. Before reuse, the farm must re-inspect the entire affected water system under farm control, identify hazards, take corrective action, and verify the efficacy of the action(s) to ensure the water meets critera; and treat the water as required.

If the agricultural water does not meet the microbial quality criteria, the farm must also, as soon as practicable, and no later than the following year, discontinue use or:

  • Apply a time interval (of no more than four consecutive days) between last irrigation and harvest, using a specified microbial die-off rate to meet the microbial quality criteria, or apply an alternative rate and maximum time interval in accordance with the rule.
  • Apply a time interval between harvest and end of storage using an appropriate microbial die-off rate and/or applying a (calculated) log reduction using appropriate microbial removal rates during activities such as commercial washing, to meet the criteria and any scientifically validated/documented maximum time interval or log reduction.
  • Re-inspect the entire affected agricultural water system under farm control, identify hazards, take corrective action, and verify the efficacy of the action(s) to ensure the water meets criteria.
  • Treat the water as required.

FDA also provides for some alternatives to microbial quality criteria and sampling as long as other requirements are satisfied and measures identified that provide the same level of public health protection.

TESTING FREQUENCY. The final rule adopts the general approach of the proposed rule for testing and frequency based on the type of water source used, but there were some changes of note. The rule requires:

  • An initial survey of untreated water that is directly applied to growing produce with annual sampling/testing to create a rolling dataset of samples for confirming that the water is used appropriately. This process is used for untreated water—both surface and ground, with some variation in number of samples.
  • For untreated ground water used for the purposes for which no detectable generic E. coli  is allowed, farms must initially test the untreated ground water at least four times during the growing season or over one year.  If this sampling meets criterion, testing can be done once annually thereafter. If any annual test fails, the farm must resume the initial year test requirement.
  • Water treated in compliance with the rule or received from compliant public water systems or supplies that meet rule requirements need not be tested.
  • Implementation of water-change schedules for recirculated water; visual monitoring of water quality or buildup of organic material; maintenance and monitoring of water temperature.

As with all FSMA rules, there are requirements for recordkeeping, such as documentation of the findings of the inspection of the agricultural water system, the results of analytical tests required by the rule, scientific support of the adequacy of the water-treatment method, results of its monitoring, the microbial die-off or removal rate(s), public water system annual results or certificates of compliance, scientific support of any alternative actions or methods.

For more specifics on the agricultural water requirements, see The Produce Rule: Focus on the Water Requirements (

David Acheson is the Founder and CEO of The Acheson Group.