Extension Responds: Flood-august 2007
Safety of Produce from Flooded Gardens
Contact: Barbara Ingham, Department of Food Science, University of Wisconsin Extension, August 2007
As a result of recent flooding, questions have been raised about the safety of consuming produce from gardens that were under water for a day or two. How concerned you have to be about using garden produce after a flood depends, to a large degree, on whether that flood water was "clean", i.e. standing rain water, or water that may have been contaminated with sewage, river or creek water, farm run-off, or industrial pollutants.
The most conservative answer — one that eliminates any and all risks — is that you discard all produce that was covered by contaminated flood water. However, with weeks left in the growing season, you may wish to salvage some crops. Here are tips for considering what can be salvaged and what must be discarded from your flooded garden.
Begin by discarding all leafy vegetables such as lettuce, cabbage, or spinach. It's not possible to scrub these crops, and they have many ridges and crevices that could contain contaminated silt or bacteria. All soft fruits such as berries should also be discarded because they too are impossible to clean.
Examine produce carefully before picking it. If it is soft or cracked, or has open fissures where contamination might have entered, throw it out. Produce from plants that survive flooding with water that was not contaminated should also be discarded if it is bruised, cracked, or otherwise blemished. Root crops from "clean" flooding should be OK if the upper parts of the plants survive essentially undamaged.
Produce that can be safely consumed in the short term is produce that will be cooked. Begin by washing green beans, tomatoes, peppers, summer squash and other mid-season crops in water. Do not use soap. Rinse with clear tap water and soak for 2 minutes in a weak chlorine solution of 2 Tablespoons bleach to a gallon of water. Rinse in cool, clean tap water. Peel and cook thoroughly before eating. Change the bleach solution if you notice the water is no longer clean.
For underground vegetables such as beets, carrots and potatoes, wash in water, rinse and sanitize as directed above. Peel and cook thoroughly before eating. Note: beets may be peeled after cooking, if desired.
Melons and other fruits which will be eaten raw should not be consumed. Recent foodborne illness outbreaks linked to melons suggest that these low-acid fruits may not be safe even if surface-sanitized.
Late-season vegetables that result from flowers produced on growth that develops after flood waters subside should be OK. To increase safety, cook them thoroughly, or at least wash them well and peel them, if possible, before eating. This could include tomatoes, peppers, eggplants, squash, cucumbers, and similar vegetables.
Flood-damaged garden produce that is otherwise unfit for eating – such as tomatoes that are cracked or decaying – should not be canned or otherwise preserved. Garden produce that would be safe to consume after washing, sanitizing and cooking may alternately be safely canned. Do not attempt to freeze or dehydrate these items, however.
Never sell produce from a flood-damaged garden at a farm market or farm stand until you are sure that all contamination has been removed from the garden, usually a period of at least one month after the last incidence of flooding. Check with the Division of Food Safety of the Department of Agriculture, Trade, and Consumer Protection (608) 224-4665 if you have questions about market sales of garden-flooded produce.