August 3, 2017

WG Releases Report on Ag Water Testing Methods

The FSMA Produce Safety Rule’s agricultural water provisions require that produce farms characterize the microbial quality of agricultural water to minimize the risks related to its use. The FDA has recently announced that it will be “revisiting” the current ag water requirements and will extend the compliance dates for the Produce Safety Rule’s ag water provisions.

The current FDA agricultural water testing requirements and the methods associated with this testing are of significant concern for produce growers due to costs and lack of available laboratories to perform the required method. Industry has concerns regarding FDA’s selection of the analyte, method, and sampling requirements for ag water in the Produce Safety Rule. The most pressing issue that challenges implementation of and compliance with the current Produce Safety Rule’s water testing provisions is the requirement to use the U.S. EPA’s Method 1603 (M1603) or an equivalent method, to analyze ag water for generic E. coli, the most commonly used indicator of fecal contamination.

In an effort to address the questions surrounding ag water testing methodologies, a panel composed of experts from academia, government and industry was convened by the Center for Produce Safety. They reviewed water monitoring data, developed a shared understanding of implementation issues, and evaluated the applicability of available water testing methods to the Produce Safety Rule requirements for public health protection.

Below are the panel’s formal water testing recommendations that were submitted to the FDA:

  • Recommend that FDA issue clarifying language publicly, as soon as possible, to convey the FDA acceptance of the US EPA’s list of approved methods to be equivalent to M1603 in meeting scientifically valid criteria for adequately protecting public health. This will provide the flexibility intended in the Final Produce Safety Rule.
  • Urge the incorporation and use of MPN calculations within the available Microbial Water Quality Profile auto-calculator spreadsheets for untreated surface and groundwater
  • Recommend that language in the Produce Safety Rule describing recognized alternative test methods be revised to remove the expectation of equivalency and substitute ‘comparable and adequate for the purpose of public health protection’ or that FDA issue draft guidance indicating this interpretation of equivalency.


For more information, contact Hank Giclas at (949) 885-2205.