(VIDEO) Is the soil the source? Or something else. Mitigators continue to report they were unable to meet contractually agreed on radon concentrations because of radon in water, building materials, or nearby sources. "What’s the responsibility of testers and mitigators to communicate the relative risks of these other sources?" What liability do they incur by either raising or not raising the issues? Then, what’s the best way of communicating and addressing those risks? (Time Limit: 60 days)