Garden Question

[Rich/WIS]

Moved to Kentucky last year and want to put in a small garden. House I bought had an above ground pool with a deck and I was going to remove the deck surface and leave the posts for a fence to keep the deer out (Daniel Boone Nat'l Forest adjoins my lot). While checking out the deck and deciding on what I needed to do discovered a tag on the pressure treated lumber used. It is the type that was treated with arsenic and the tag had all sorts of warnings. Concerned that over the last dozen or so years arsenic may have leached into the soil and if so would be absorbed into anything I grow. Anyone have any experience with this situation?

[Minerat]

Call you local Natural Resources Conservation Service (NRCS) office they may be able to help.

[NyFirefighter357]

https://extension.psu.edu/environmen...treated-lumber


Most of the contamination is at the base of the posts. If the wood is older most of the leeching has happened already. I would remove the soil about 1ft deep by 1ft around each post. Scrap off the top couple of inches of the surface dirt under the deck add compost & peat and roto till the soil. If you really want to be safe scrape off a sample from the middle a few inches deep & have it tested.

[rancher1913]

people have been using pt wood for years and before that even worse stuff, its mostly a california scare and label. dont plant at the base of the posts. if your really worried scrape off the top inch or so and add a lot of compost. you dont plan on eating the posts do you? that might present a problem.

[waksupi]

https://extension.psu.edu/environmen...treated-lumber


Most of the contamination is at the base of the posts. If the wood is older most of the leeching has happened already. I would remove the soil about 1ft deep by 1ft around each post. Scrap off the top couple of inches of the surface dirt under the deck add compost & peat and roto till the soil. If you really want to be safe scrape off a sample from the middle a few inches deep & have it tested.

Good solution. Call a government agency, you may find yourself a hazmat site, and cost yourself thousands.

[Froogal]

I've built several things using pressure treated lumber in the last 10 to 15 years. None of that lumber carried any warnings about arsenic. The deck on the front of our house is built out of PT lumber. Wife planted many different kinds of flowers all around it. The flowers and bushes are all very healthy.

[rancher1913]

there is usually a plastic tag stapled to the end of the boards. you should never burn any pt wood in an indoor woodstove or fire place because it does give of poison gas when burned. the whole pt wood thing is a lot like lead paint, we all grew up with it but now its a death sentence to be around it.

[poppy42]

Years ago wood Was Treated with chromated copper arsenate, which contain arsenic. Substances containing arsenic were commonly used as an insecticide years ago also, especially for the treatment of dry wood termites. When you saw the big tenty over houses that said fumigation in progress! that stuff generally had some type of arsenic in it that’s why all the warning signs up. Chromated copper arsenate has not been used since ( I don’t remember exactly ) sometime in the early 2000’s . So if your decks been around for 20 years roughly it’s very possible that the wood was CCA treated. As others have said after this length of time more than likely any leaching has long since stopped but to be on the safe side as long as you keep any vegetable plants 2 foot away from the post you should be OK. Once again it was a long time ago but I seem to recall some type a EPA warning that said not to plant anything to be consumed within 18 inches of CCA treated wood. I’m sure if you were to google CCA treated wood you would come up with the regulations and suggestions for safe handling and planting around it . Like I said we’re talking about the stuff not being used for 15 or 20 years. Anything I’ve posted is going off memory and let’s face it I am getting any younger so I could be miss remembering some dates or distances be on the safe side do your own Google search but I wouldn’t be overly concerned as long as I didn’t plant anything directly on top of the posts.
Good luck and be safe

[Shawlerbrook]

I wouldn’t be too concerned. The levels that leach probably are not that high. Anyone that lives in or near an old orchard probably has much higher levels as arsenic was used as a pesticide for years. I worked as a State pesticide regulator for 32 years.

[woody1]

https://en.wikipedia.org/wiki/Chromated_copper_arsenate

[Hogtamer]

Use of CCA treated wood is guaranteed to give you a flyer out of an otherwise perfect 10 shot group. It also turns green beans and tomato worms green. Get a double dose from your forearms resting on that ole picnic table and you won't be eaten by termites. Now the stuff they use isn't as effective but it turns squash yellow. There's always old creosote cross ties but they turn your eggplant black and are the cause of terrible splinters. Prolly more danger from arsenic in the constant use of anything with semiconductors and hard lead shot. If I knew how to incorporate purple font I would do so!

[WRideout]

Two of the states I have lived in have what is called the agricultural extension service, that is there to help farmers and home gardeners. In KY the University of Kentucky is the host for that service. https://extension.ca.uky.edu/ The extension agent would probably be happy to talk to you about the treated wood. I know I have gotten much useful information from them.

Wayne

[JonB_in_Glencoe]

I would remove the posts.
I wouldn't worry about what might have leached out of the wood into the soil, it's probably diluted to such a low concentration, that it wouldn't be a concern, and probably most all washed away. Dilution is the solution to pollution, at least that's what the Government has taught me.

FYI, when I was a child, my parents had several gardens. One of them was a raised bed made of salvaged railroad ties. After a couple years, tomatoes wouldn't grow in that soil. My Dad figured out the problem. He removed the ties and planted grass there. The grass grows just fine. We moved from that house many years ago. I drove by recently, there is a cement sidewalk and water fountain there now.

[Rich/WIS]

UPDATE: Called our local extension and spoke with to them about the issue. Answer was not to worry, although arsenic may have leached there would not be enough to matter, apparently this is a common question. My plan was to use raised beds and roto till in topsoil as the ground is clay and then set the beds. Went to plan B, which is to set the beds on landscape cloth and add topsoil over it, which reduces potential contamination to about zero.

Thanks everyone for the help, especially the advice about calling the extension office.

[WRideout]

When my dad was a kid in OK on the farm, they used to use powdered arsenic as a pesticide. Another man I knew said he used to shake a bag of it on the cotton crop; apparently every old cotton field has some arsenic in it.

Wayne