Cheryl Cary is at the 2026 Chlorinated Conference in Fort Worth, Texas

We're proud to share that Cheryl Cary is at the 2026 Chlorinated Conference in Fort Worth, Texas, presenting her work on sub-slab pressurization as a strategy for improving vapor intrusion mitigation system (VIMS) design—research conducted alongside co-authors Steve Michelson, PG, and Elizabeth Hwang, EIT.

Her poster explores a real-world case study at a multi-building, multi-family housing development in Northern California, where the installed passive sub-slab ventilation system didn't meet performance objectives. The team adapted the existing infrastructure into a sub-slab pressurization system (SSPS), introducing ambient outdoor air to create a pneumatic barrier against contaminated soil vapor.

While the SSPS successfully attenuated sub-slab VOCs, a slight increase in radon concentrations in indoor air due to operation of the SSPS could not be statistically ruled out based on the existing data. Additionally, closed-loop testing revealed that the gravel and concrete slab themselves emitted radon, creating an unavoidable concentration floor. The takeaway is that SSPS can be effective, but it must be paired with additional engineering controls, such as an engineered barrier system, to manage radon risk.

If you're at the conference, stop by #181 in the Exhibit Hall from 4:30pm-6:00pm to connect with Cheryl and talk vapor intrusion. We'd love to see you there!