Is it safe to use rain water collected using rain barrel to water vegetables?
Thank you for contacting the Toronto Master Gardeners with your timely question.
Collection of rain water from roofs through the use of rain barrels is growing in popularity because of its environmental and practical benefits.
There have been numerous studies done by various Universities to look at potential contaminants from roof run-off water. The main concern is that metals, chemicals and other by-products can leach off of your roof along with the rain water. A second concern is E. coli contamination in the roof run off water due to animal and bird feces.
According to the University of Connecticut’s article Can I Water Vegetables with my Rain Barrel Water?
“Dr. Mike Dietz, Assistant Extension Educator at UConn with expertise in water management recommends “not using roof water on anything leafy that you are going to eat directly. It would be OK to water soil/plants where there is no direct contact”. This is consistent with recommendations from other experts who suggest applying the water directly to the soil and avoiding contact with above-ground plant parts.”
This is also recommended by the University of Arkansas Division of Agriculture in their article Safe Use of Rain Barrel Water . “It is best to use rain barrel water on ornamentals, trees and lawns, but if you choose to use rain barrel water on your vegetable and fruit plants, the safest way to do it is by watering the soil and not the plant itself. Direct contact of rain barrel water on the harvestable portion of the crop could result in chemical or pathogenic contamination.”
Myths About Rainwater Harvesting Systens for Gardens written by Robert Pavlis is an excellent article that provides the latest information backed by scientific research.
May 26, 2021