Rotting (pitting) lally columns

Has anyone ever seen or heard of this problem: all 8 lally columns in my basement are rusting/pitting/splitting. The house is 18 years old. The basement has never had water problems (leakage or water on the floor), but is somewhat damp. The rust is not only at the bottom of the columns, but is distributed fairly evenly from top to bottom. The rust seems to be starting in areas that look like pits and radiating out from there. Sometimes there is water oozing from the center of the pits that looks like it could be coming from the inside.
A corrosion expert from the Port Authority of NY/NJ has told me that it sounds like the columns may need cathodic protection, i.e, they are forming a kind of electrochemical cell by reacting with the soil. I've measured a voltage from the columns to the cold water ground of about 0.3 V. This seems too low to indicate the need for sacrificial anodes and the like.
If someone has heard of this, is there anything I can do besides replacing all 8? Do I need to worry about the same thing if I replace them? How much would something like this cost, anyway?
Thanks.
Tony
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TonyT wrote:

Oozing columns...? Are the columns hollow pipe or concrete filled? If you have pits working their way out, what you see is probably not nearly as bad as the inside. I'd consider drilling a 1/4" hole a few inches down from the top and using a borescope to check out what's going on inside.
Replacement cost estimates could vary substantially depending on whether the columns are embedded in the slab, bolted or welded to the beam, availability of your local qualified contractors, etc.
ZRC is a pretty big name in the corrosion coating business: http://www.zrcworldwide.com / Check out the cold galvanizing coatings.
R
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