VAPOR INTRUSION MITIGATION
Case Study: 1 Million Square Foot Warehouse, Northeast U.S. A recent EAI project involved a 1-million square foot brownfield
redevelopment for a warehouse facility development. Crews
Figure 2. Low-profile venting installed in the field. This design reduces the need for deep trenching while supporting sub-slab depressurization systems (SSDs) as part of a layered vapor intrusion mitigation approach.
Figure 4. Blower system schematic showing dual-blower setup with piping connections and integrated controls.
installed multiple active SSD blower skids, over 20,000 linear feet of low-profile venting, and a full spray-applied barrier system. Installation took place through winter, requiring close attention to environmental conditions and curing. Our quality control team conducted phased smoke testing across every slab section, with all phases passing on the first attempt.
To ensure both vapor barriers and SSDS deliver reliable
Figure 3. Spray-applied vapor barrier installation at the grade beam and slab interface. This monolithic application ensures full coverage and chemical resistance, sealing vapor intrusion pathways around footings, utility penetrations, and critical slab transitions.
• Add protective top sheet (for spray-applied membranes) • Install blower systems for active SSDS where applicable • Perform QA/QC testing before pouring the concrete slab
A certified installer will ensure that every transition and
penetration is sealed using manufacturer-approved techniques and verified via smoke testing.
Lessons from the Field: Where Systems Fail (and How to Prevent It) Barriers and SSDS can underperform if not supported by rigorous
field practices. Common problems we’ve seen include: • Late-stage slab penetrations made without sealing • Barrier damage from rebar, tools, or foot traffic • Rushed work without proper curing, testing, or inspection
To counteract these issues, we conduct mandatory pre-slab
coordination, use protective mats over installed membranes, and test every section prior to pour. These practices mirror the EPA’s recommendations for building-specific QA/QC.
www.aipg.org
protection, we implement QA/QC procedures immediately following installation—before slab pour or final cover-up. These include smoke testing to verify membrane seals and detect preferential pathways, tracer gas testing to assess sub-slab airflow, and thorough visual inspection of all seams, penetrations, and wall terminations. These procedures align with best practices, verified in guidelines like the ITRC Vapor Intrusion Mitigation Post- Installation Fact Sheet (
https://vim-1.itrcweb.org/post-installation- fact-sheet/#Smoke-and-Tracer-Gas-Testing), which identifies these methods as high-impact tools for verifying the integrity and performance of both active and passive mitigation systems.
Robust Vapor Mitigation: Active Venting and Vapor Barriers for Real-World Performance Mitigation is no longer just about compliance—it’s about
durability and adaptability. EPA guidance and public outreach both point to the value of combining active venting with vapor barriers and long-term QA/QC for sites such as landfills, brownfields, and redevelopment sites.
By treating mitigation as a system—not just a product—teams
can deliver performance that holds up under real-world stress, seasonal variation, and evolving site use. Whether the building is a healthcare clinic, school, warehouse, or commercial space, the goal remains the same: protect indoor air with reliable, proven strategies backed by data, experience, and guidance from the field.
About the Author Robert Carvalho holds a Bachelor of Science in Geology from
Hofstra University and is a Certified Professional Geologist (CPG). He has over 30 years of experience managing and directing a wide range of environmental projects as the President and CEO of EAI, Inc.
https://www.eaienviro.com/.
Jan.Feb.Mar 2026 • TPG 43
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