I had two houses that failed the radon test (above 4.0). Atlantic Radon responded quickly to both residences, did their own computer measurement, and installed their radon mitigation, all at a very reasonable price. The results were excellent, with one house getting a 0.7 average and the other a 0.9. I recommend them highly.
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.