Our house already had a radon system when we moved in about two years ago. I did a radon test and found our levels were elevated (between 4 and 6 pCi/L). I did not have information on who originally installed our radon system, so I called Radon Environmental to see what we could do. Chris from Radon Environmental came out and tested our system and found that it wasn't drawing well. He also noted that the outside exhaust was installed incorrectly (too low and too close to a window) and that the fan size in our system was not ideal. He thought he could fix the problem by digging a bigger suction pit for the system but noted that an additional suction line might be necessary. We have an unfinished basement with a dirt crawl space that extends about 1/3 of the floor space, so we decided to seal that. He thought that would help with the radon and noted that it would help with allergies as well. When he came to do the work, he was able to fix it without adding another suction line, which saved us money. Radon Environmental was experienced, friendly, prompt, and professional. I recommend them without hesitation.