Water testing for the FSMA Produce Safety Rule

Important update

The FSMA Produce Safety Rule on Pre-Harvest Agricultural Water was released in May 2024.
The Final Rule is substantially different from the previous pre-harvest agricultural water rule.
The revised rule only applies to pre-harvest water, which is generally for irrigation purposes or for crop protection. This is different from the requirements for postharvest water, which were not changed.
The testing requirements for pre-harvest water have been removed.
The rule now requires that growers conduct a qualitative Agricultural Water Assessment to determine the quality of their water and to document risks to it.

What does the updated Rule on Pre-Harvest Agricultural Water require?

The revised rule requires growers to conduct an Agricultural Water Assessment (AgWA) instead of relying on testing the water. The FDA provides a summary of the Final Rule on Pre-Harvest Water.

The AgWA is a holistic assessment of risks to water used on the farm, including risks from nearby septic systems, runoff from animal operations, faulty wells and other infrastructure that might pose a risk to your water quality that you use for pre-harvest uses. Farms use the information that they gather as a part of an AgWA in their decisions about their water use.

Water testing can be used as an input to the AgWA under some circumstances, but it is not required.

What are the exemptions from conducting an Agricultural Water Assessment?

If the water source is groundwater that meets the testing and quality criteria for drinking water (meaning no detectable Generic E. coli in 100/ml) an AgWA is not required.

If the water is received from a public water system or supply that meets requirements established in the rule an AgWA is not required.

Note: To use these exemptions you must be reasonably certain that the quality of the water will not change prior to the water being used as agricultural water.

When will farms have to comply with the revised Subpart E rules?

All other businesses (>$500K): April 7, 2025
Small businesses (>$250K-500K): April 6, 2026
Very small businesses (>$25K-250K): April 5, 2027

Where does this leave growers now?

For now, continue to learn more about the quality of your agricultural water to reduce the potential that it might become a source of contamination of your fresh fruits and vegetables. If you like, you can still test that water for E. coli to understand the quality of the water, and use that information in combination with an Agricultural Water Assessment.

The FDA has created an Agricultural Water Assessment builder that you can find here.

Find more information on testing water on your farm.

If you have questions related to if your farm is subject to the Produce Safety Rule, please contact MDA's Produce Safety program.

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.

List of water testing labs in Minnesota

Water testing labs in Minnesota by county

Laboratory name	Address	County	Phone	Contact	Method type: Quantitative (Q), Presence/Absence (P/A) or Both
A.W. Research Laboratories, Inc.	16326 Airport Rd., Brainerd, MN 56401	Crow Wing	218-829-7974	Sara Ahlerf	Both
AC Analytical & Consulting LLC	21518 Basset Dr. NW, Puposky, MN 56667	Beltrami	218-243-3328	Kevin Caroline	P/A
Central Water Testing Laboratory	18511 State Highway 371, Brainerd, MN 56401	Crow Wing	218-828-2118	Margaret Bevorak	P/A
Davy Laboratories	115 6th St. S, La Crosse, WI 54601	La Crosse	608-782-3130	Jennifer Buchholv	Both
Fillmore SWCD Water Quality Laboratory	900 Washington St. NW, Preston, MN 55965	Fillmore	507-765-3878	Nikki Wheeler	Both
Instrumental Research, Inc.	7800 Main St. NE, Fridley, MN 55432	Anoka	763-571-3698	Sue Melchior	Both
Interpol Laboratories, Inc.	4500 Ball Rd. NE, Circle Pines, MN 55014	Anoka	763-786-6020	Gregg Holman	P/A
Koochiching Health Department Water Testing	1000 5th St., International Falls, MN 56649	Koochiching	218-283-7070	Derek Foss	P/A
Minnesota Valley Testing Laboratories, Inc.	1126 N Front St, New Ulm, MN 56073	Brown	507-354-8517	Gloria Anderson	Both
Pace Analytical Services, LLC - Duluth, MN	4730 Oneota St., Duluth, MN 55807	St. Louis	218-727-6380	Leah Morehouse	Both
Pace Analytical Services, LLC - Minneapolis MN	1700 Elm St. SE, Suite 200, Minneapolis, MN 55414-2485	Hennepin	612-607-1700	Issac Schmidt	Both
Pace Analytical Services, LLC - Virginia	315 Chestnut St., PO Box 1212, Virginia, MN 55792	St. Louis	218-735-6700	Craig Douglas	Both
Red Wing City Laboratory	1020 East Fifth St., Red Wing, MN 55066	Goodhue	651-385-5141	Kelsey Vandeusen	Both
RMB Environmental Laboratories, Inc.	2200 West 94th St., Bloomington, MN 55431	Hennepin	218-846-1465	Autumn Mahoney	Both
RMB Environmental Laboratories, Inc. Detroit	22796 County Highway 6, Detroit Lakes, MN 56501	Becker	218-846-1465	Autumn Mahoney	Both
RMB Environmental Laboratories, Inc. Hibbing	1111 7th Ave E, Hibbing, MN 55746	St. Louis	218-440-2043	Kristin Hanson	Both
Saint Paul-Ramsey County Public Health	555 Cedar St., St Paul, MN 55101	Ramsey	651-266-1321	Page DeLong	P/A
Southeastern Minnesota Water Analysis Laboratory	2100 Campus Dr. SE, Rochester, MN 55904	Olmsted	507-328-7495	Seth Cordry	Both
Southwest Health and Human Services	607 West Main St., Suite 200, Marshall, MN 56258-3099	Lyon	507-537-6713	Chad Cunningham	P/A
Stearns DHIA Central Laboratory	825 12th St. S, P.O. Box 227, Sauk Centre, MN 56378	Stearns	320-352-2028	Angela Scherping	P/A
Steven M. Traut Wells, Inc.	754 Cross Country Lane SW, Alexandria, MN 56308	Douglas	320-762-1528	Tarra Darin	P/A
Techtron Engineering, Inc.	640 East Main St., Anoka, MN 55303	Anoka	763-712-9502	Joshua	P/A
Traut Water Analysis Lab	141 28th Ave. S, Waite Park, MN 56387	Stearns	320-251-5090	Sue Fish	P/A
Tri-City/William Lloyd Analytical Lab	9300 Poplar Bridge Rd., Bloomington, MN 55437	Hennepin	952-563-4904	Deb Weltzin	Both
Twin City Water Clinic, Inc.	617 - 13th Ave. S, Hopkins, MN 55343	Hennepin	952-935-3556	Bill VanArsdale	P/A
UC Laboratory	129 North Main St., Janesville, MN 56048	Waseca	507-234-5835	Ben Schreder	Both
Water Laboratories, Inc.	333 Main St. NW, PO Box 388, Elk River, MN 55330	Sherburne	763-441-7509	Kevin Kloeppner	Both
Worthington Public Utilities Laboratory	1950 27th St. N, Worthington, MN 56187	Nobles	507-372-8660	Mike Pavelko	P/A

This list is current as of July 22, 2021.

It is updated regularly to add laboratories that offer the methods that are allowable under the FSMA Produce Safety Rule.

To update the above information, add your company to the list, or ask a question, please email [email protected].

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.

Quantitative methods (allowed for production or post-harvest water)

Method 1603: Escherichia coli (E. coli) in Water by Membrane Filtration Using Modified membrane-Thermo tolerant Escherichia coli Agar (Modified mTEC) (September 2014). U.S. Environmental Protection Agency. EPA-821-R-14-010.
Method 1103.1: Escherichia coli (E. coli) in Water by Membrane Filtration Using membrane-Thermotolerant Escherichia coli Agar (mTEC) (March 2010). U.S. Environmental Protection Agency. EPA-821-R-10-002.
Method 1604: Total Coliforms and Escherichia coli in Water by Membrane Filtration Using a Simultaneous Detection Technique (MI Medium) (September 2002). U.S. Environmental Protection Agency. EPA-821-R-02-024.
9213 D – Natural Bathing Beaches (2007). In: Standard Methods for the Examination of Water and Wastewater, 22nd Edition (Rice E.W., et al., Ed.), 9-46 – 9-48. Washington, DC: American Public Health Association. (2012).
9222 B – Standard Total Coliform Membrane Filter Procedure (1997), followed by 9222 G – MF Partition Procedures (1997) using NA-MUG media. In: Standard Methods for the Examination of Water and Wastewater, 21st Edition (Eaton A.D., et al., Ed.), 9-60 – 9-65, and 9-70 – 9-71, respectively. Washington, DC: American Public Health Association (2005).
D 5392-93 – Standard Test Method for Isolation and Enumeration of Escherichia coli in Water by the Two-Step Membrane Filter Procedure. In: Annual Book of ASTM Standards, Volume 11.02. ASTM International. (1996,1999, 2000).
Hach Method 10029 for Coliforms – Total and E. coli, using m-ColiBlue24 Broth PourRite Ampules.
IDEXX Colilert Test Kit, but only if using IDEXX Quanti-Tray/2000 for quantification.
IDEXX Colilert-18 Test Kit, but only if using IDEXX Quanti-Tray/2000 for quantification.

Presence/absence methods (allowed for post-harvest water only)

TECTA^TM EC/TC medium and the TECTA^TM Instrument: A P/A Method for the Simultaneous Detection of Total Coliforms and Escherichia coli (E. coli) in Drinking Water. (2014).
Modified Colitag^TM Test Method for the Simultaneous Detection of E. coli and other Total Coliforms in Water. ATP D05-0035. (2009).
IDEXX Colilert Test Kit
IDEXX Colilert-18 Test Kit
IDEXX Colisure Test Kit
E*Colite Bag or Vial Test for Total Coliforms and E. coli in Potable Water. Charm Sciences
101298 Readycult Coliforms 100. EMD Millipore (division of Merck KGaA, Darmstadt, Germany).

To better understand the Produce Safety Rule, we recommend taking the FSMA Grower Training course and these sources:

Produce Safety Alliance: The Water Analysis Method Requirement in the FSMA Produce Safety Rule Overview (2018).
FDA Equivalent Testing Methodology for Agricultural Water (2018).
FDA Fact Sheet Key Requirements: Final Rule on Produce Safety (2015).
MDA Produce Safety Program includes location and registration information for FSMA grower training.
UMN Extension Farm Food Safety Program includes location and registration information for FSMA grower training.

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

Reviewed in 2026