Pond Boss Forums INTRO Questions & Observations Pressure Treated Lumber

I have some pressure treated lumber that I want to build a dock for my new pond will the chemicals leach into my water and cause any problems to my fish or livestock.

I used treated lumber as pilings for my dock and have not had any problems at all. There is a new treated lumber out now that doesn't have the so called bad chemicals that the old treated lumber had. I wouldn't worry about it.

Same here. I have had on problems in my .62 acre pond. In fact, the fish hand out around it and are defintely there during feeding time. Additionally I attach floating cages of juvenile bass, bluegill, and perch with no problems.

I posted this same question in Dec '03 in this same forum ( you can check it out if you want). Didn't get a conclusive answer ( if anyone really knows for sure). My concern was for gradual leaching of arsenic into the pond. It could then follow the food chain up to the fish and then into yourself ( similar to mercury). My concerns would be gradual poisoning from accumulation over a period of time. Chronic toxicity can result in various cancers, skin ailments, GI and nervous system problems. My two cents would be to find an alternative.

Sarc

I also posted a question regarding the effects , if any, from the use of the cca treated timber used in my pier some 14 years ago. This was soon after the announcement that the industry would stop using the arsenic in treated timber. I got several good responses. The concensus was it shouldn't be a problem. Not sure there is any actual data available. I was advised by someone on this forum not to let the timber rot in the pond. I had the water tested and it was safe for drinking by the standards set for public water consumption. The pond bottom soil near the timber had arsenic content but I was told soil has a certain amount of arsenic anyway. I decided the pier was there and I wouldn't worry about it.

I should add that I had the same concerns as Sarchasm. Even though I'm not doing anything about my existing pier, I share Sarchasm's 2 cents and would and would find an alternative today.

my two cents - I am certainly no expert on chemical hazzards of treated lumber, however if you are talking about the old arsenic containing pressure treated lumber, I do know that a lot of local governments pulled out playground equipment to avoid exposure and possible long term side effects of that exposure so if it was me I'd use something different. If it is the newer "safer" version of pressure treated lumber I wouldn't be as concerned.

Just an FYI - the new treated lumber, ACQ is causing fasteners to deteriorate over short periods of time. As a building inspector we are working on changing everyone in our jurisdiction to triple dipped galvanized or stainless fasteners. In a research project normal deck screws showed severe signs of deterioration in under 6 months.

This might be a good time to call the Wildlife Biolgist in your neck of the woods. At least they have some chemistry background and certainly can bump it up the chain to get real data. I gotta think that the little red tag stapled to the end of each board means something...

FYI:

Here is some interesting information on treated lumber and arsenic. Nothing directly related to ponds but I think the message is relatively clear. Treated Lumber

Since everyone threw in their 2 cents, here's mine : If you're 100 miles from a major city, avoid the treated lumber...If you not, there's so much other trash washing in, they all neutralize each other right ?

Well, that (above link) covers the chemistry question. Gotta go, need to paint the treehouse now...

The article is a little reactionary but begs the question, why take any chances? It says that a 12-foot section contains 250 lethal doses but doesn't tell you if its a 2 x 4, 4 x 4, etc. Clearly they are trying for maximum impact.

If you knew how much wood you had in a dock and could determine the amount of arsenic in the wood, you could divide the arsenic mass by the number of gallons in the pond to determine the worse case arsenic water concentration. Most states have criteria for surface water and of course drinking water. In Michigan the drinking water criteria is 50 micrograms per liter and for surface water its 150 micrograms per liter.

That means if you had a pond with 4-acre feet of water, you would need about 1/2 pound of pure arsenic added to the water to exceed the drinking water standard and about 1.5 pounds to exceed the surface water standard.

The good news is that not all of the arsenic in the wood would leach out, and if it did leach, not all would remain in the water. Arsenic has a strong affinity to organic sediments. The actual amount of arsenic needed to exceed the water criteria would be higher because some of the arsenic would be bound to sediments, etc.

Arsenic in Michigan occurs naturally in soils on the east side of the state at concentrations that are on the average 6 times the concentration on the west side. The soil concentration on the east side commonly exceeds the health-based standard. The difference is due to the presence of shale bedrock on the east side (remember the organic affinity). If you are still concerned about arsenic, eliminate or paint the treated wood. You can take a soil sample to an environmental lab for an arsenic analysis for about $10. Many health departments will provide a free arsenic analysis for drinking water wells.

Hope that helps

More arsenic info

Steve,
If I could give you another star I would!

Indeed, fine info Steve, well put.

Thanks.