Should I test my well water and soil for arsenic when trying to grow fruit trees?
I have a low level of arsenic in my well water (between .01-.015 mg/L). I understand that I can use water with up to .1 mg/L arsenic to irrigate outdoor crops, but so far have been using rainwater to irrigate my outdoor garden. I am thinking of planting fruit trees in my yard. I don’t expect to have enough rain water to irrigate them as they are getting their roots established. Is it safe to water them with my well water? Should I get the soil tested as well, and if so, what would a safe soil arsenic level be for fruit trees?
Abi Griffith, Horticulture Community Education Assistant
As you know, the levels of arsenic in your well water are low enough to use to water your crops, so it would still be ok to water fruit trees as well. I’m including two fact sheets for you to refer to if you need more information/reassurance:
- Oregon State University bulletin Arsenic in Well Water
- Maine CDC Bulletin Arsenic in Your Well Water
Arsenic can be naturally occurring so that could be the source of the problem, but also, if the land was a former farm or orchard, arsenic can be from sprays used years ago as arsenic was a commonly used product in fruit tree production. It could be a good idea to get a soil test if your land was used as a farm or orchard in the past, and for the added bonus of getting lots of information about the quality of your soil. Keep in mind that testing for arsenic is not included in a standard soil test. Based on the Soil Lab Price page (see #8), you would have to test for metals ($60) with the arsenic add on test ($70).
Go to Soil Test on our website for all the information you need about ordering and taking a soil sample.
This article from Washington State may also be helpful!