Atlantic Radon recently installed a radon remediation system at our house. Our radon levels went from 4.5 to .8, so we are very happy with the results. I find the owner, Tom, to be highly knowledgable, professional and honest. Another company wanted to charge more than double to do unnecessary work. Tom took a step by step approach, meaning that if the initial radon remediation did not do the trick, he would then look into doing additional work like sealing the crawlspace. He also didn't try to upsell me on a sump pump, pointing out the reasons why it wasn't necessary at this time. If you go with this company, you can't go wrong!
I can't say enough about how great it was to work with Atlantic Radon. They were able to come out the same day I contacted them for an estimate, which was in line with the others I received. However, it was their service which sold me on them. They were friendly, prompt, and very understanding of our chaotic household, since we're in the middle of a move. They even offered to speak to our buyers if they had any questions after the fact. Can't recommend them enough for radon mitigation.