Vapor Intrusion Mitigation Systems

Protecting your investment from hazardous vapor intrusion through cost-effective, innovative, and regulatory-compliant solutions.

The Challenge of Vapor Intrusion in Brownfield Development

Vapor Intrusion conceptual site model.

When industrial contaminants like petroleum hydrocarbons or chlorinated solvents (e.g., PCE or TCE) linger in soil or groundwater, they can release vapors that migrate upward into buildings. This process, known as vapor intrusion, poses serious health and safety risks if not addressed. Exposure to volatile organic compounds (VOCs), methane gas, and radon can result in headaches, respiratory issues, or more severe long-term health effects. Methane, in particular, poses significant fire and explosion hazards if allowed to accumulate indoors.

California regulators require thorough assessment and mitigation of vapor intrusion as part of Brownfield redevelopment projects. Failure to proactively address vapor intrusion can lead to costly redesigns, extended agency review, and occupancy delays. New construction and property transactions in areas with known contamination must often include vapor mitigation planning and implementation to gain agency approvals and protect building occupants.

Trinity’s VIMS Solutions: We Turn Regulatory Hurdles into Occupancy Approval

CQA inspection of base rock and collection piping.

Trinity Source Group, Inc. (Trinity) transforms environmental liabilities into safe, usable spaces that are ready for occupancy approval. We provide full-service VIMS to developers and property owners in Northern and Central California. From evaluation and design to installation and long-term monitoring, our team ensures that every VIMS is engineered to meet regulatory requirements while minimizing cost, complexity, and schedule impacts.

Our Services Include:

  • Consultation and Planning: Early integration of vapor mitigation strategies during due diligence or site assessments to reduce surprises and avoid costly delays.

  • Site Investigation & Assessment: Soil gas sampling, indoor air testing, and pressure diagnostics to evaluate vapor intrusion risks.

  • Custom VIMS Design: Sub-slab depressurization, venting systems, vapor barriers, building retrofits, and more – tailored to your site's contamination profile and building plans to avoid overdesign and unnecessary expense.

  • Regulatory Coordination: Workplan development, permitting, and agency negotiations handled by experienced professionals who know what regulators expect.

  • Installation & Construction: In-house crews install VIMS components using cost-effective, durable materials under licensed supervision.

  • Operations, Monitoring & Maintenance: Long-term OM&M support including sensor-based alerts, inspections, and sampling to protect occupants and maintain compliance long after occupancy.

Why Trinity?

CQA inspection of vapor barrier to ensure that all penetrations and barrier overlaps are sealed.

  • Proven Experience: Established in 2005, with successful VIMS projects across the San Francisco Bay Area and Central Coast.

  • Turnkey Capability: Full-service team of environmental consultants, engineers, and licensed contractors under one roof, simplifying communication and accelerating delivery.

  • Regulatory Know-How: Trusted by California’s DTSC, Water Boards, and air districts – we streamline compliance and reduce delays by anticipating agency concerns early.

  • Custom, Cost-Effective Designs: Solutions that meet health goals without overbuilding or inflating budgets.

  • Advanced Monitoring: Remote telemetry and system alerts ensure real-time awareness and reliable system performance.

  • Client Success Stories: From dry cleaner redevelopment to passive industrial system retrofits – our VIMS enable safe occupancy and regulatory closure.

CQA inspection prior to concrete pour rebar to identify and repair any damage caused during installation of rebar.

Need a Vapor Intrusion Mitigation Strategy?

Whether you're building on a Brownfield site or remediating an existing property, Trinity can help. Get in touch with Trinity early to reduce uncertainty, speed approvals, and protect your investment. Our end-to-end vapor intrusion services are trusted, compliant, and proven to keep people safe and projects moving forward.

Contact Us Today

DTSC Vapor Intrusion Guidance

BAACMD