Homes with multiple foundations, or that are particularly difficult to mitigate may combine mitigation techniques.
Sump Pits
Sump pits may be used as a secondary suction point, but must not be used as the primary suction point for any mitigation system unless the basement of the home being mitigated has radiant heat lines installed in or below the floor.
Although view ports are allowed on sump pit lids, they are no longer a mandatory requirement. The radon vent must include provisions for the removal of the sump lid for maintenance of the sump pump.