We are buying a house that was found to have a basement radon level of 4.2 pCi/L - above the EPA's recommended action level. We had a radon contractor come out and drill a test hole in the slab, after which he said the soil was too wet to install a standard radon mitigation system (PVC pipe, fan, vented to the outside) and that we should think about using an air exchanger.
It makes me concerned to think that is the end of the road for using a standard mitigation system. Surely there are other locations/basements with wet soil that do have succesful radon mitigation systems installed with reduced radon levels. Is it possible for sub-slab soil to be too wet to use a radon mitigation system? Should I get another opinion/contractor to take a look? He did show me the soil, and while it was damp, it wasn't dripping water and I didn't see any water in the test hole.
Thanks for your help!