US Patent 11913674 Non-permeable radon sump mitigation system

A planar, pliable sealing member is provided as a flexible seal for covering an upper opening of the well pit for any configuration of sump pump system. The sealing member forms a continuous membrane that provides a gas seal formed of any suitable non-gas diffusive or selectively gas diffusive material, including various elastomeric rubbers, such as butyl rubbers or other similar or functionally equivalent polymeric or co-polymeric rubbers. A seal at an outer periphery hat forms a continuous adhesive seal. The membrane further forms access orifices to allow for the passage of egressing structures such as pump discharge, ventilation, sump electrical connections, etc. A second sealing element is then applied or affixed providing an air-tight seal between the membrane at each orifice and a surface of any egressing structure. The second sealing element may be a similar adhesive, mastic or caulking material as with the first sealing element.