Vapor Intrusion Mitigation System Design – San Francisco

February 20, 2026
Vapor Intrusion, Vapor Intrusion Mitigation System, Vapor Intrustion Mitigation

Terra-Petra’s Environmental Engineering Division has partnered with a leading environmental consulting firm in the Bay Area to design a comprehensive Vapor Intrusion Mitigation System (VIMS) for a new high-rise residential-rental mixed-use building located in San Francisco, CA.

We will be following the Department of Toxic Substances Control (DTSC) Vapor Intrusion Mitigation Advisory to design a combination passive venting and sub-slab membrane VIMS system as a means of mitigating human health risks associated with PCE in subsurface soil vapor. Our services will also include providing the necessary Quality Assurance/Quality Control Oversight during the installation of the system. This is a process and a role that we feel very comfortable carrying out.

Regardless of the reason, Terra-Petra can design a vapor intrusion mitigation system for you. We routinely design these passive and active Building Protection Systems across numerous cities and counties governed by many different agencies.

A typical Building Protection Systems consists of an impermeable soil vapor membrane and a pressure relief system. Where deemed appropriate, Terra-Petra can design mechanical vapor extraction systems, electronic gas detection and alarm systems; employing the latest technologies.

Among our many capabilities, Terra-Petra offers:

  • A Civil Engineer, Registered Environmental Assessor, Registered Geologist and Certified Engineering Geologist on staff.
  • Years of experience designing code compliant Building Protection Systems for numerous governing agencies.
  • Easy to read comprehensive plans including project specific details and specifications.
  • Passive and Active Design Capabilities.
  • Plan coordination with project Architect, Civil, Structural, Plumbing, HVAC as well as the Landscape Architect.
  • CAD Draftsmen on staff carry an Associates of Science Degree in Computer Aided Drafting Technology and Certificates in Architecture and Design for Drafting.

Radon Mitigation System – Summit County, CO

February 20, 2026
Radon mitigation system, Vapor Intrusion Mitigation System, Vapor Intrustion Mitigation

Terra- Petra is pleased to partner with a major property developer in Colorado to provide environmental engineering services for the design of a radon mitigation system for their development in Summit County, CO.

The project will consist of the construction of one single family home, and five  attached single family residences all with 3 stories and no basement. The homes are all nearly identical, with an approximate footprint of 2,500 SF. The project requires that a radon mitigation system be “roughed in” for future activation if needed, but our client is requesting that Terra-Petra design radon mitigation systems for each of the proposed buildings.

Terra-Petra has recommended that we design a combination passive venting and sub-slab membrane Radon Mitigation System for the proposed development.

Vapor Intrusion Mitigation System – Palo Alto, CA

February 20, 2026
CQA/CQC, State of California Construction, Terra-Petra News, Vapor Intrusion, Vapor Intrusion Mitigation System, Vapor Intrustion Mitigation

Terra-Petra’s Environmental Engineering Division has partnered with a significant environmental consulting firm in the Bay Area to prepare a comprehensive Vapor Intrusion Mitigation System (VIMS) for a new development located in Palo Alto, CA.

Terra-Petra designed the passive mitigation system with the ability to convert it to an active system in the future if deemed necessary. The VIMS System was reviewed and approved by the Department of Toxic Substances Control (DTSC).

Having completed the VIMS design we have moved on to the construction administration phase which includes submittal review and RFI responses, as well as the QA/QC inspections. We are currently on-site overseeing the smoke testing of the subslab membrane system.

For more on this project visit the City of Palo Alto Website

Vapor Intrusion Mitigation Design – Hayward, CA

February 20, 2026
Vapor Intrusion, Vapor Intrusion Mitigation System, Vapor Intrustion Mitigation

Terra- Petra is pleased to continue partnering with a major property developer to provide Vapor Intrusion Mitigation System (VIMS) Design Assistance in Hayward, CA. The scope of work involves mitigation of VOCs that could pose a potential vapor intrusion concern into a future occupied structure at the site.

This includes document review, conducting a Human Health Risk Assessment (HHRA) and submission of a Basis of Design report complete with Construction Quality Control procedures and an Operation, Maintenance and Monitoring plan (OM&M).

The vapor intrusion mitigation system will be designed in accordance with the Alameda County Department of Environmental Health’s Local Oversight Program (ACDEH) and in general accordance with the Vapor Intrusion Mitigation Advisory published by the C.A. EPA Department of Toxic Substances Control (DTSC) dated October 2011 (Cal/EPA 2011a, 2011b).

Vapor Intrusion Mitigation System Design – Pomona, CA

February 20, 2026
Vapor Intrusion, Vapor Intrusion Mitigation System, Vapor Intrustion Mitigation

Terra Petra is currently working with a client to provide full scope vapor intrusion mitigation system design (VIMS), inspection, and monitoring services for their development in Pomona, CA.

The proposed development will consist of two new slab on grade, 3-story multi-family affordable apartment buildings with a combined footprint of 26,330 SF.

Terra-Petra will work with the City of Pomona (permitting agency) and with The Los Angeles County Department of Public Works (LACoDPW), Environmental Programs Division (EPD) which prescribes means and methods of protecting structures from vapor intrusion.

vapor intrusion mitigation

Terra-Petra to attend topping off celebration for 2747 Park project in Palo Alto

February 20, 2026
, , CA projects, Construction Industry, Enivronmental Engineering, Environmental Construction, Northern California Projects, Vapor Intrustion Mitigation

The Level 10 team is set to celebrate the topping out of the the 2747 Park project on Thursday, October 5th. Designed by  the Jay Paul Company, this development is steps from Caltrain in Palo Alto, California. 2747 Park provides a future-forward workplace designed for Silicon Valley’s innovative workforce. Terra-Petra has been invited to attend the event having designed the vapor intrusion mitigation system for the site. Level 10 will also have the topping out beam available for signatures onsite beginning October 3rd.

Terra-Petra’s GM/VP Justin Conaway to speak at the Colorado Environmental Management Society March 10

February 20, 2026
, , , , , , , , , , , Colorado Region, Environmental Construction, Environmental Engineering, Terra-Petra Company News, Uncategorized, Vapor Intrusion, Vapor Intrustion Mitigation

JustinConawayVPGM Terra-Petra GM/VPCEMS March Luncheon – Engineering Control Trends in Vapor Intrusion Mitigation – March 10

Speaker: Justin Conaway, Vice President |General Manager and Patrick Guan, Regional Manager, Terra-Petra Environmental Engineering.

Tuesday, March 10, 11:30am – 1:00pm.  There will be no CLE for this presentation.

In recent years the implementation of vapor intrusion mitigation systems has become more common for ground-up development. There are many different forces and factors that are influencing this rise in popularity. There are also numerous engineering controls available to protect a given building from vapor intrusion. This presentation discusses the Vapor Intrusion Mitigation Engineering Control Trends that are being specified and installed today on new construction projects. The benefits of these systems will be outlined and we will identify how various stakeholders have influenced the current trend.

Justin Conaway, VP/GM of Terra-Petra has been with the company since 2004. In this time he has developed a unique knowledge of the vapor intrusion industry in that he has been involved with nearly every aspect of the vapor intrusion cycle from site characterization through installation.

Mr. Conaway has a wealth of experience and competencies, including: Construction Quality Assurance Inspection, Mitigation System Design, Permitting, Document Submittal and Negotiations with Governing Agencies, Risk Management Decision Making Process with Developers, Contract Negotiation, Installation Costing, On-Going Operation and Maintenance Monitoring and Reporting, and Research and Development to launch innovative vapor intrusion products.

Patrick Guan, Regional Manager for Terra-Petra has been with the company since 2012. In this time, he applied his vast experience in sales/marketing, strategic planning, operational management, and superior customer service skills that he developed over the past 17 years working for fortune 500 companies to help drive the ambitious expansion goals of Terra-Petra from a regional success story to a thriving successful nationwide operation. He has done this by executing a clear and concise marketing campaign that presented a positive compelling brand identity for the company. He helped increased the company’s market share throughout the country by emphasizing Terra-Petra’s expertise, and superior value driven customer service that has made it so successful in the West Coast region.

LOCATION: The EPA Conference Center located on the 2nd floor of the EPA Region 8 Headquarters building at 1595 Wynkoop Street in Denver, Colorado. 

To register, please visit this link. 

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