Ryan I would agree with your comments. I am a mitigator in Va. and have 30 years of experience and have done thousands of mitigations. I feel that we indeed need good sound regulations that provide consistency in mitigation systems. I also feel that how regulations effect the cost and availability of mitigation for the average consumer is very important. Our goal should be to create regulations that lead to the installation of safe, effective, and durable mitigation systems. Not put undue burden on mitigation contractors that may reduce the amount of mitigation systems they are able to perform. I would agree that our area probably has a shortage of quality mitigation contractors. The ultimate goal should be to provide as many safe, efficient, and durable mitigation systems as possible. There has to be enough regulation to create and maintain the industry without hampering the number of systems the industry is able to install.

I am in Virginia but deal with lots of difficult mitigations in my area. If you have the entire slab under a negative pressure confirmed by communication testing it is likely that the remaining source is not under the slab. if you happen to have a garage slab or other large slab on the main living level in some cases the radon trapped under that slab can be coming into the hollow block walls. If that is the case a suction point through the block wall into the gravel bed under the elevated slab can do the trick. I have had a similar situation and found very high levels coming into the basement around a Well line. Hopefully this will help.