Interestingly enough my company is working on this subject as we speak and the CCA was discontinued for residential use. It however is still being manufactured for commercial and construction uses. The industry is moving rapidly away from the CCA but the leading candidate ACQ uses quats as a component and that is expensive and you have to load up the wood with more copper to deal with the efficacy loss with respect to CCA. The ACQ also has corrosion problems with certain types of fasteners.

There are other options that are coming up rapidly like Silicate based formulas that basically infuse the wood with liquid glass and then heat it to lock things in place. A company by the name of Timbersil is the manufacturer of that technology. With that formula there is no leaching issues and the stud lasts at least 75 yrs in a wet environment. The wood is also lighter in weight and can be painted or stained unlike plastic composite woods.

I wish I could say that is my companies product but we are coming up with an equally interesting option that is more environmentally friendly. If you want to talk pressure treating or wood sometime in more detail please feel free to give me a shout.

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1/10 - 1/4 acre pond plus 16 ft deep/ Plus 40 ft by 20 ft by 6 ft deep koi and fathead minnow pond next to it. Upstate NY