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Water testing for the FSMA Produce Safety Rule

Important update

The FDA has released revisions to the previous language in the Produce Safety Rule about water testing and they are seeking comment on the proposed language.

  • On Dec 2, 2021, the FDA released the proposed revisions to Subpart E - Agricultural Water for the FSMA Produce Safety Rule.
  • The proposed language in the rule is substantially different from the previous water testing rules.
  • Until the new rule is final, continue to follow previous guidance as contained on this page

To read more about the proposed agricultural water testing rule under the FSMA Produce Safety Rule:

Some key things to note about the proposed agricultural water rule:

  • Enforcement discretion applies while the rulemaking process is completed and compliance dates are re-evaluated. That means that the existing provisions of Subpart E Agricultural Water will not be in effect until the rule-making process is done.
  • The FDA is seeking comments from growers and others who are impacted by the proposed rule. Providing comments is important, as the FDA will use the comments to finalize the law that might impact many growers. The comment period ends April 5, 2022.
  • You can submit comments about the rule to the FDA Federal Register Docket 
  • Continue to assess your water quality and take actions you deem appropriate to reduce the risk of contamination to produce.

For more guidance on the new rule including tips for making comments, see this blog post from UMN Extension.

The FSMA Produce Safety Rule requires that labs use approved testing methods to run these tests, to ensure results are accurate. The water labs listed conduct these allowable testing methods.

For more information on specific water testing requirements under the Produce Safety Rule, see resources at the end of this page or attend a FSMA Grower Training workshop.

This list does not endorse any specific business or testing method. There may be other companies that offer allowable methods for water testing in the state.

When looking for water testing services:

  • Call the lab to ask about their protocol for gathering a sample.
    • Tell them you want to test your ground or surface water samples for generic E. coli using a method allowed by the FDA under the FSMA Produce Safety Rule.
    • Make sure to tell the lab whether the sample is from a surface or well water source, as the testing methods might change based on the source.
  • Water used in the pack house or for other postharvest uses can be reported as presence/absence (P/A) results. But water used in the field (production) must be analyzed by a quantitative method that results in a number.
    • Tell the lab you need an actual number for your irrigation water sample results.
    • The list of water labs on this page shows if a lab can perform both quantitative and presence/absence, or just presence/absence tests.
  • You will receive a sampling kit and instructions from the lab. Follow these instructions carefully: wash your hands before sampling and do not touch the inside of the container.
  • Set a time when the sample should arrive at the lab.
    • Some labs have small incubator capacity and cannot process every sample they receive. Sometimes they do not run samples every day.
    • It is best to call ahead and make sure the lab has the time and capacity to process the sample within the allotted hold time.
  • Some labs can arrange to pick up a sample from a farmer or a drop-off location, but you will need to know the exact day and time you will be sampling.
  • Get the sample to the lab as soon as you can after collection, always within the hold time indicated by the lab.
    • Some labs accept mailed samples, while some require drop-offs.
    • Keep the sample at refrigerator temperatures.

Allowable testing methods for FSMA Produce Safety Rule

The FDA has determined that the following methods are scientifically valid and at least equivalent to the method of analysis stated in the Standards for the Growing, Harvesting, Packing, and Holding of Produce for Human Consumption (FDA regulation § 112.151(a)), in accuracy, precision and sensitivity.

These are the allowable methods of testing agricultural water for farms covered by the FSMA Produce Safety Rule.


Authors: Annalisa Hultberg, Extension educator; Nusrat Annie Jahan, College of Veterinary Medicine and Fernando Sampedro, School of Public Health

Reviewed in 2021

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