When you’re developing a brownfield site or managing a commercial property, there’s an invisible threat that could be compromising the health of future occupants—and your project’s success. Vapor intrusion is a serious environmental concern that affects thousands of buildings across the United States, yet many property owners and developers don’t fully understand it until they’re facing regulatory hurdles, liability issues, or worse—health complaints from building occupants.
At Clean Vapor, we’ve spent 38+ years protecting human health by addressing vapor intrusion challenges. With over 30 million square feet of buildings successfully mitigated and 1,200+ projects completed, we’ve seen firsthand how proper vapor intrusion mitigation protects both people and investments. Let’s break down what vapor intrusion is, why it matters, and how to address it effectively.
What Is Vapor Intrusion?
Vapor intrusion occurs when harmful chemical vapors from contaminated soil or groundwater migrate upward through the ground and enter buildings through cracks, gaps, and openings in foundations. These volatile organic compounds (VOCs)—such as trichloroethylene (TCE), perchloroethylene (PCE), benzene, and other petroleum hydrocarbons—can accumulate indoors, creating health risks for occupants.
Think of it like radon, but instead of naturally occurring radioactive gas, you’re dealing with chemical vapors from industrial contamination. These vapors follow the path of least resistance, moving through soil gas and finding their way into basements, ground-floor spaces, and even upper levels of buildings through elevator shafts and utility penetrations.
The challenge? Vapor intrusion is often invisible, odorless, and undetectable without proper testing. By the time someone notices a problem, occupants may have been exposed for months or years.
Why Vapor Intrusion Matters for Human Health
The ultimate purpose of addressing vapor intrusion is protecting human health. Long-term exposure to VOCs through vapor intrusion can cause serious health effects, including:
- Respiratory problems and irritation
- Neurological effects and headaches
- Liver and kidney damage
- Increased cancer risk from certain compounds
- Developmental effects in children
For property developers, building owners, and environmental consultants, vapor intrusion represents both a health responsibility and a significant liability. Regulatory agencies at state and federal levels have established strict guidelines for vapor intrusion assessment and mitigation. Failure to address vapor intrusion can result in delayed permits, costly remediation, litigation, and reputational damage.
The Four-Phase Approach to Vapor Intrusion Solutions
At Clean Vapor, we take a comprehensive, site-specific approach to vapor intrusion mitigation. There’s no such thing as a one-size-fits-all solution—every site has unique geology, contamination profiles, and building characteristics that demand custom engineering.
Diagnose: Understanding Your Vapor Intrusion Challenge
The first step is thorough assessment. This involves:
- Soil gas testing to measure VOC concentrations beneath and around the building
- Indoor air quality sampling to establish baseline conditions
- Site characterization to understand soil types, groundwater depth, and vapor migration pathways
- Building inspection to identify potential entry points and pressure differentials
Our team works closely with Licensed Site Remediation Professionals (LSRPs) and environmental consultants to gather the data needed for proper system design. We’ve learned over three decades that accurate diagnosis is the foundation of effective mitigation.
Design: Engineering Custom Vapor Intrusion Mitigation Systems (VIMS)
Once we understand your site, we design Vapor Intrusion Mitigation Systems tailored to your specific needs. Our PE-signed and sealed designs comply with ANSI/AARST standards, AVIP Best Practices and state-specific regulations. Tom Hatton, our founder, literally helped write the industry standards for vapor intrusion mitigation—this isn’t something we approach casually or learned from a YouTube video.
Design considerations include:
- System type selection: Active sub-slab depressurization, passive venting, or hybrid systems
- Vapor barrier specifications: Selecting appropriate materials for your building type and contamination levels
- Extraction point placement: Strategic positioning based on building footprint and soil conditions
- Fan sizing and redundancy: Ensuring adequate pressure field extension and airflow with backup systems for critical applications
- Monitoring integration: Incorporating real-time telemetric monitoring for response-driven controls
For new construction projects, we specialize in passive system designs that prevent vapor intrusion from day one. Our track record speaks volumes: 500+ passive new construction designs with zero failures requiring conversion to active systems.
Build: Professional Installation by Trained Specialists
Proper installation is where many vapor intrusion projects fail. A brilliant design is worthless if it’s executed by an untrained contractor or plumber who treats it like a simple exhaust fan installation. Vapor intrusion mitigation requires specialized knowledge of building science, soil gas behavior, and system integration.
Our installation process includes:
- Precision slab penetrations that maintain structural integrity
- Proper sealing of all cracks, utility penetrations, and potential vapor entry points
- Installation of certified vapor barriers, including LandScience, Epro and Cetco spray-applied gas barriers where appropriate
- Strategic piping design that minimizes visual impact while maximizing performance
- Quality assurance testing to verify pressure fields and system effectiveness
We don’t just install equipment—we create integrated systems that work seamlessly with your building’s HVAC, plumbing, and structural elements.
Monitor: Ensuring Long-Term Performance and Compliance
Vapor intrusion mitigation isn’t a “set it and forget it” solution. Contamination levels change, building conditions evolve, and regulatory requirements become more stringent over time. That’s why ongoing monitoring is essential.
Clean Vapor is the exclusive supplier of the patented Vapor Guardian telemetric monitoring systems, which provide:
- Real-time system performance data accessible from anywhere
- Automated alerts when parameters fall outside acceptable ranges
- Response-driven controls that adjust system operation based on actual conditions
- Compliance documentation for regulatory reporting
- Predictive maintenance capabilities to prevent system failures
This continuous oversight ensures your vapor intrusion mitigation system protects occupants year after year, not just on installation day.
Common Vapor Intrusion Scenarios
Understanding where vapor intrusion occurs helps property stakeholders recognize their risk:
Brownfield Redevelopment: Former industrial sites, dry cleaners, gas stations, and manufacturing facilities often have soil and groundwater contamination that creates vapor intrusion risks. These properties offer tremendous redevelopment potential, but vapor intrusion must be addressed for occupant safety and regulatory approval.
Commercial and Multifamily Buildings: Large footprint buildings with ground-floor retail, offices, or residential units face unique challenges. Vapor intrusion can affect multiple tenants simultaneously, creating complex liability scenarios.
Existing Buildings Near Contamination: Even buildings constructed before contamination occurred can experience vapor intrusion if contaminant plumes migrate under the structure. Off-site vapor intrusion requires careful assessment and sometimes cooperative mitigation efforts.
Regulatory Compliance: State-Specific Standards and ANSI/AARST Requirements
Vapor intrusion regulation varies significantly by state. Some states have aggressive screening levels and require active mitigation at lower concentrations, while others follow EPA guidance more loosely. States like New Jersey, California, New York, and North Carolina have particularly rigorous vapor intrusion programs.
Compliance requires:
- Understanding applicable screening levels for target compounds
- Following proper sampling protocols and quality assurance procedures
- Submitting PE-signed designs where required (like in North Carolina, where we operate as Clean Vapor Engineering, P.C.)
- Meeting ANSI/AARST standards for system design and installation
- Maintaining documentation for institutional controls and long-term stewardship
Our team stays current on evolving regulations across all states where we work, ensuring your project meets—or exceeds—applicable requirements.
Why Experience Matters in Vapor Intrusion Mitigation
The vapor intrusion mitigation field is filled with contractors who treat these systems like simple radon mitigation or think installing a vapor barrier is as straightforward as laying down plastic sheeting. The reality is far more complex.
With 38+ years of experience and over 100 years of combined team expertise, Clean Vapor has encountered virtually every vapor intrusion challenge imaginable. We’ve mitigated sites with extraordinarily high VOC concentrations, designed systems for buildings with complex foundations, and solved problems that stumped less experienced firms.
Our guarantees back up our confidence: we provide 1+ year warranties on systems we design and install, and our passive system track record—zero failures in 500+ projects—speaks to the quality of our engineering and installation.
Protecting Human Health Through Better Indoor Air
Vapor intrusion is a solvable problem, but only when addressed by professionals who understand the science, the engineering, and the stakes. Cutting corners, using unqualified contractors, or implementing inadequate solutions puts occupants at risk and creates long-term liability.
Whether you’re a property developer evaluating a brownfield site, an environmental consultant managing a vapor intrusion investigation, or a building owner facing compliance requirements, Clean Vapor brings the expertise and proven track record you need.
We’re a family-owned company built on honesty, integrity, and quality of character. We don’t over-promise or hype—we deliver custom, site-specific solutions that protect human health and comply with regulations.
Ready to discuss your vapor intrusion challenge? Email us at info@cleanvapor.com or schedule a meeting with our team. Let’s work together to create indoor environments where people can live, work, and thrive safely.
Clean Vapor—The Vapor Intrusion Mitigation Company™. Protecting human health through 35+ years of expertise, 30+ million square feet mitigated, and a commitment to engineering excellence that sets the industry standard.
