Want to know a bit more about how vapor intrusion mitigation works?  Contact us at keane@xdd-llc.com.

Email XDD at keane@xdd-llc.com for case studies associated with our vapor intrusion mitigation experience.

Vapor Intrusion Mitigation

Soil Vapor Mitigation System - Midwest Location

Vapor Intrusion Mitigation System – Midwest Location

XDD has completed extensive vapor intrusion evaluations and designed mitigation systems for both our private and federal clients. We help our clients by understanding the root of the problem (soil, groundwater, structure materials, processes used by the current tenant), governing state and federal regulations and options to manage risk and mitigate the problem. How We Can Help EPA guidance on evaluation of vapor intrusion potential at RCRA, UST, Brownfield, and Superfund sites has prompted numerous states to adopt screening and testing criteria. Our expertise, experience and credibility enable XDD to:

  • Quickly screen sites and identify potential liability for current or potential property owners,
  • Evaluate impact of soil and groundwater remedies on vapor intrusion,
  • Conduct investigations into active processes that might have impacted sub-slab soils or degrade indoor air quality,
  • Provide guidance on best available practices for direct measurement of indoor air, sub-slab and soil vapor VOC concentrations and relative contribution of background sources,
  • Provide low cost, effective mitigation when required, and
  • Provide the necessary qualifications to provide credible representation for our clients to agencies and the public.

Vapor Intrusion Mitigation Technologies and Services:

  • Active Depressurization Technologies (ADT) Design and Installation:
    • Sub-Slab Depressurization
    • Sub-Slab Ventilation (SSV)
    • Sub-Membrane Depressurization (SMD)
  • Building pressurization and Sub-Slab Pressurization
    • Passive barrier technologies
    • Engineering for new construction and property redevelopment
    • Site Screening and Modeling


Our Credentials Our scientists and engineers have worked on some of the largest vapor intrusion sites in the country, developing EPA guidance on collection of indoor air and sub-slab air samples (EPA/600/R-05/147), engineering and implementing cost-effective mitigation systems.

  • XDD has performed numerous vapor intrusion assessments, designs, and installations of ADT systems at Superfund, NPL, military, and industrial/residential properties.
  • XDD has worked with USEPA to develop vapor intrusion sampling protocols and guidance documents (e.g., EPA/600/R-06/11 and EPA/600/R-05/147).
  • Our experience in Soil Vapor Extraction (SVE) is directly applicable to vapor mitigation. Proper design of ADT systems is directly related to SVE design concepts. XDD’s founders are among the pioneers of SVE technology and have assisted USEPA in developing design and performance guidance documents for this technology.
Vapor Intrusion Mitigation Fan

Vapor Intrusion Mitigation Fan

Example Experience:

  • Developed an innovative Active Depressurization Technology (ADT) solution for a historical landmark building with a complex mix of foundation types and earthen floored crawlspaces in Detroit, MI. This building contained unique challenges such as groundwater and surface water infiltration into functioning floor drains/sumps, partially excavated areas beneath the building slab, and difficult to treat areas such as elevator shafts and a smoke stack. XDD certified the design to meet stringent state and federal agency requirements for conversion of the building to residential use. Performance certification of the design by XDD aided in project approval and for receiving funding for the $52M building renovation project.
  • Provided Sub-Slab Depressurization (SSD) design for mitigation of VOCs and radon for three residential housing developments containing over 300 units and community center buildings at the Ellsworth AFB, South Dakota.
  • Conducted vapor intrusion assessment and vapor mitigation for residential properties located downgradient of a Fortune 50 Industrial Client site which was impacted with chlorinated solvents in Indiana Subsequent air monitoring demonstrated that indoor air meets IDEM action levels.
  • Designed and installed a large scale Sub-Slab Ventilation (SSV) system for a Fortune 500 Industrial Client at an NPL Site in TN. The SSV was installed as part of 300,000 ft2 manufacturing facility expansion.
  • Designed a unique slab-on-slab SSD/SSV system for a former Fortune 50 Industrial Client site in TX. Developed specifications and performance requirements for ADT installation in future building construction which was incorporated into the Environmental Land Use Restriction (ELUR) for the site.
  • Contributing author to USEPA’s “Assessment of Vapor Intrusion in Homes Near the Raymark Superfund Site Using Basement and Sub-Slab Air Samples.” EPA/600/R-05/147. March 2006.
  • Contributing author to USEPA’s “Comparison of Geoprobe® PRT and AMS GVP Soil-Gas Sampling Systems with Dedicated Vapor Probes in Sandy Soils at the Raymark Superfund Site.” EPA/600/R-06/111. November 2006.