Water system mapping for food safety

Though not required by the Food Safety Modernization Act Produce Safety Rule, a water system map can be very helpful in an inspection. Here are some key features to include in a water system map.

February 20, 2019 - Author: ,

Map of a water system
The map does not need to be professionally created or even drawn to scale. Simple line drawings are often enough. Have a key for all relevant features on the map. Drawing by Phil Tocco, MSU Extension,

Whether you are looking to create a food safety manual for a Good Agricultural Practices (GAP) audit or keep documentation for Food Safety Modernization Act (FSMA) compliance, a map of the whole water system is a good place to start. Many GAP audits require keeping a map of the water system. Though not required by the FSMA Produce Safety Rule, it can be very helpful in an inspection.

When creating a water system map, it’s important to remember that a water system begins with the water source and extends all the way to the last emitter. Delineate all blocks and separate units either on one big map or several small maps, depending on how detailed you want to be. The key should be to keep the map detailed enough to be of value to you.

On a water system map, key components to be labeled might include water sources, locations of backflow preventers, potential sources of contamination, pressure sensors and locations where hydrants connect to and terminate on the distribution system.

Water sources. Include all wells, ponds and streams where irrigation and crop water are taken from. If there is a special name for a water source that is used by the farm for water testing, recordkeeping purposes, or to communicate to other farm employees who are irrigating from that source, make sure to include that on the map.

Backflow preventers. Indicating where check valves or air gaps are located can be important to help other farm employees quickly find them for testing. It also helps you clearly double check that no cross connections or points of potential contamination occur between the source and the check valve. It might also be helpful to indicate if check valves are buried or above ground.

Sources of contamination. Potential sources of contamination include mixing and loading pads, composting areas, manure lagoons and chemical or fuel storage. Having these clearly indicated on the map can allow you to prioritize those areas for greater care.

Pressure sensors. In cases where there are multiple pressure sensors with each one monitoring a separate block, having each block mapped will help you locate where changes in pressure indicate line breaks or blocked emitters.

Hydrant connection points. Having these on a map can help you understand if the source is protected against backflow of the hydrant, a potential source of contamination. In cases where these connections occur between a source and a backflow preventer, they can help alert you to areas where you can improve.

Mapping may seem like a chore at first, but it can help you think through your system and identify areas of concern before they become problems. To find out more about water system maps, check out this helpful Youtube video created by Michigan State University Extension. If you have specific questions about water system maps as they relate to the Produce Safety Rule or have difficulty creating one, contact the Michigan State University Extension Agrifood Safety Work Group at gaps@msu.edu or 517-788-4292.

Funding for this article was made possible, in part, by the Food and Drug Administration through grant PAR-16-137. The views expressed in the written materials do not necessarily reflect the official policies if the Department of Health and Human Services; nor does any mention of trade names, commercial practices or organization imply endorsement by the United States Government.

Tags: agrifood safety, fsma, irrigation water systems, msu extension, produce safety rule


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