Proposed irrigation water standards

It’s important to be aware of Food Safety Modernization Act water standards. This article outlines the proposed standards and gives information about how to learn more.

The proposed Food Safety Modernization Act (FSMA) is the most sweeping legislation regarding raw agricultural products in 70 years. Though not yet final, it is important to understand that few changes are expected in the final rule. The FSMA spans over 500 pages and is extremely complex. One area of particular complexity is the issue of irrigation water testing for fresh produce and what standard to use when testing water.

The rule proposes the use of the EPA body contact standard for generic E. coli. For reference, the standard is no more than 235 colony forming units (CFU) of generic E. coli in any one sample and a rolling average of 126 CFU over the last five samples. This standard is not unfamiliar to large scale lettuce growers who will recognize the standard as adopted by the leafy greens marketing agreement for irrigation water. (To avoid confusion, growers should note the EPA body contact standard found in the FSMA is more stringent than Michigan’s body contact standard of 300 CFUs.)

Generic E. coli is more specific than a general coliform test. They are a subset of coliform bacteria. Coliforms naturally occur in the environment and can be generated by vegetative or animal sources. All E. coli are coliforms, but not all coliforms are E. coli.

To clarify, not all E. coli will make people sick. Some strains of E. coli are harmless bacteria that live both in the soil and in our bodies. Other strains don’t usually cause illness, but can under the right conditions. Still other strains are truly pathogenic and will cause illness. Recognizing this, it becomes clear that by testing for generic E. coli, growers are following a standard that provides for an abundance of caution.

If water quality and irrigation are of interest to you, Michigan State University Extension is hosting a 2014 Irrigation Workshop on March 17 to discuss irrigation and water management in agriculture. Workshops will provide information relevant to all irrigators, including growers of field crops, fruits, vegetables and ornamentals (2 RUP credits).

This workshop will be held at Cabela’s (White Tail and Moose rooms) in Dundee, MI. Onsite registration will begin at 8:30 a.m. with the program starting at 9 a.m. and will conclude at 4:30 p.m. Lunch, refreshments and materials are included. Registration is $50 per person by March 10. Onsite registration is $75 per person.

For more information about this irrigation workshop or to register, visit the 2014 Irrigation Workshops registration page. Contact Lina Rodriguez Salamanca at 517-264-5300 or with any questions.

If you would like more information on irrigation water standards or general water testing info, contact the MSU Extension Agrifood Safety Workgroup at 517-788-4292 or and ask for Guidance Document AFSM-024.

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