Although a natural disaster earns headlines for fatal injuries and destruction of property, a "minor" flood may damage your garden and ruin your season's produce. Learn to protect yourself and your family.
How a Flood may Contaminate Your Garden
A flood may damage a garden in three very visible ways, but invisible contamination is the most dangerous.
Visible harm includes soil erosion, silt deposits, and damage to the plants. Walkways, fences, benches and other constructs might also show the effects of a flood, including being washed away altogether.
Another problem that may come to light is root damage or rotting fruit.
Yet the greatest health risk to the vegetable gardener comes after the floodwaters recede, leaving contaminants and disease-causing organisms behind. The three major types of contaminants are organic waste, living organisms and inorganic chemicals.
Organic Waste Deposited by Floods
Organic waste includes sewage, manure, feces from cats, squirrels and other animals, as well as any bacteria that may be released when animals drown in a flood.
North America is not immune, even though such conditions are more often associated with natural disasters in the Third World. The Canadian town of Walkerton in Ontario experienced disease and death in May, 2000. The cause was eventually traced to E. coli from cow manure that entered one of the town's wells due to a minor flood.
Other natural disasters, including the earthquake in Haiti, may leave a legacy of cholera due to contaminated drinking water. In Walkerton, the contamination was not noticed until after residents fell ill. On Sept. 22, 2011 it was reported that two million people in Pakistan had become ill with diarrhoea, malaria, skin infections and snake bites after monsoon rains left vast areas under about a metre of water.
Silt deposits are visible reminders that floodwaters can carry light solids and deposit them anywhere.
Living Organisms Carried by Floods
Living organisms include E. coli and other bacteria found in sewage. Parasitic worms may also be carried by flooded rivers and deposited on vegetables. Both parasites and bacteria may work their way into garden produce. These are impossible to simply wash off.
Flooding Spreads Inorganic Contaminants
The flood may have swept around automobile engines, poorly sealed paint cans, land fill sites and garbage bins. Heavy metals, petroleum products, insecticides and herbicides may dissolve into the water and be absorbed by growing plants.
Stored Produce is Also at Risk in Floods
Produce, whether vegetables or fruit, that has been harvested may also be contaminated if the flood had reached the storage area. All the same risks named for growing vegetables also apply to harvested produce.
Even Orchards may be Contaminated by Flooding
Low hanging fruit may have been splashed if the waters swirled. Other contaminants may be drawn up by the roots of fruit trees.
What You Should Do with Flooded Produce
Annuals, such as most vegetables, should be considered lost. Do not eat fresh; do not cook; do not can or preserve or freeze.
Fruit trees and other perennials should be safe in the next season. Ginger Pryor of Penn State's Master Gardener Program recommends waiting for four full months after the flood recedes before fruit would be safe to eat.
Fungicides might be applied to plants to avert rotting. A check with the local authorities should be made if there is any doubt about which products are recommended for a particular region.
Decontamination Procedures after Flooding
Boots, gloves, and gardening tools should be disinfected after walking or working in a flooded garden. There is just as much likelihood of carrying E. coli in the silt on one's gloves as from handling contaminated vegetables.
Dunking these items into a disinfectant solution of "one part bleach to nine parts water" should be sufficient, assuming one does not normally eat from the shovel. Thorough handwashing is another important step.
If part of the garden was not flooded, treat the flooded area as a quarantined hospital room. Work in the clean area first, then in the flooded section; and decontaminate afterwards.
If there is any chance that a drinking well has been contaminated, it and any water lines must be decontaminated also.
Rays of Hope after a Flood
Simple puddles or standing water in a garden are not considered floods and do not constitute a health hazard, assuming the puddle does not include a pile of manure.
By the next growing season, rain and time should have restored your garden or orchard to its natural, healthy state.
Disclaimer: The information contained in this article is for educational purposes only and should not be used for diagnosis or to guide treatment without the opinion of a health professional. Any reader who is concerned about his or her health should contact a doctor for advice.
References:
Penn. State University via Medical Xpress, "Fruits and vegetables submerged by flood water are not safe to eat", published Sept. 22, 2011, referenced Sept. 22, 2011.
Raj Ahluwalia et al, CBC, "Death on Tap: The Poisoning of Walkerton", web page based on "The National" broadcast May 24, 2000, referenced Sept. 22, 2011.
"Two million sick from Pakistan floods", AFP via PhysOrg, published Sept. 23, 2011, referenced Sept. 23, 2011.
Mike DeHaan - Copyright (c) Mike DeHaan, B. Math., of DeHaan Services. Well written and well researched freelance articles; ghost writing for clients.
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