Have you done a soil test for arsenic?

[junctiongardenergirl]

I’ve seen public service announcement-type ads around, which recommend testing soil in King County before planting a garden because of the possibility of arsenic in the soil. Does anyone have information that they can share about this? I would really appreciate it.

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[herongrrrl]

Here’s King County’s website about this:

http://www.kingcounty.gov/healthservices/health/ehs/toxic/TacomaSmelterPlume/background.aspx

I’ve done a bunch of research on this because I was concerned for my own garden. The key thing to remember is that arsenic “dilutes” in soil very quickly and easily when the soil is disturbed. Unless the soil where you’re planning to make your garden hasn’t been disturbed at all in the last 50 years or so, your soil is probably fine. The places of most concern are in Tacoma and on Vashon/Maury. Friend of mine who live on Maury built raised beds and brought in clean soil, and don’t grow any root vegetables as precautions.

What I haven’t been able to find out is whether or not some plants absorb more arsenic or other impurities from the soil than others. If anyone knows where to find that, I would love to know!

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[junctiongardenergirl]

Thanks herongrrrl, that is very helpful information. :) Most of my plants are in raised beds, but I made my husband dig up a section of our lawn last summer to plant corn, and I have been a little nervous about it ever since I heard about the copper smelting plant. All of my neighbors have vegetable gardens (without raised beds) and eat fruit from their trees, so I am hoping that if their soil is okay, mine will be too. We removed the top 6-8 inches of grass/soil and I have added a lot of clean soil and compost to that area, which will hopefully help. But you can never be too careful. :)

I found this info regarding which plants absorb the most arsenic at http://cru.cahe.wsu.edu/CEPublications/eb1884/eb1884.pdf, which might be helpful:

“Green beans and other legumes appear to be most sensitive to soil arsenic contamination.

They often fail to grow at soil arsenic concentrations which cause no deleterious effects on other

plant species. Growth patterns of stone fruit trees such as peaches and apricots are very sensitive

to elevated soil arsenic; apples and pears are less sensitive, and cherries are intermediate.

Information about growth sensitivity of other crop species is sparse. The stunting effect of soil

arsenic may have horticultural benefits. Although the results are difficult to predict, arsenic

stunting can control the size of ornamental plants and fruit trees.

The distribution patterns of lead and arsenic among various plant parts is highly variable.

Seeds and fruits typically have lower lead and arsenic concentrations than do leaves, stems or

roots. Roots and tubers usually have the highest lead and arsenic concentrations, with the skin

having higher lead and arsenic concentrations than does the inner flesh. The lead content of

roots correlates more closely to soil lead than does lead in leaves or stems, possibly because

roots tend to retain absorbed lead and not transport it higher up into the plant. Tree fruits such as

apples and apricots contain very low lead and arsenic concentrations. Contamination of plant

parts by lead- and arsenic-rich soil or dust can increase the apparent lead and arsenic content of

that plant.”

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[herongrrrl]

Glad what I posted was helpful. Thanks for sharing that link/info!

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[JayDee]

If you do plant a raised bed, please use regular lumber or Trex-type wood to frame it. I have seen many curb-side veggie gardens in West Seattle constructed out of treated wood (likely treated with CCA or chrome-copper arsenate). The worst was one of those progressive-potato boxes where the entire thing was constructed out of CCA-treated wood.

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[JoB]

good point…

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[dawsonct]

Another alternative are recycled PET boards (not certain what they are called). From what I understand they are chemically stable and they won’t deteriorate in OUR lifetimes.

When I see the neighbors I’ll find out the name of the product.

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You can also just mound fresh dirt wherever you are putting the garden. Put down cardboard or plenty of newspaper where you want to put the beds and mound dirt on them. It won’t look quite as formal, but once the garden is established it will be much more flexible.

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[ghar72]

We have veggies growing in wine barrels. Assumed they were safe since they store wine in them. But??? Anyone have a definite answer to that one?

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[homedk]

One consideration to keep in mind with regard to soil testing, is that if high levels of arsenic or any other contamination are found on your property, you will need to disclose that when/if you ever decide to list & sell your home. Soil contamination is a big deal to many potential home buyers & the process to have soil contamination cleaned up could be a big expense.

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