mitigation for high radon 3

https://radonsysteminstallationtalk.evercolumn.com/posts/new-standards-in-radon-system-installation-reshape-residential-safety

The house had high radon, over the EPA's action level, so I read up on mitigation. We installed a sub-slab depressurization system. They cut a hole in our basement floor, sealed around a pipe running up and out the side of the house, and connected it to a small fan running continuously. That fan creates negative pressure under the slab, pulling radon-laden soil gas away before it can enter the living space. We also sealed all cracks and openings in the foundation. A follow-up test showed levels…