Vapor Intrusion is a buzz word that is gaining velocity throughout the industry. Vapor Intrusion refers to the migration of Soil Gas Vapors emanating from the earth into an occupied space or structure. The particular vapors of concern are volatile organic compounds (VOCs), including chlorinated solvents, petroleum hydrocarbons, methane, hydrogen sulfide and semi volatile organic compounds (SVOCs) to name a few. Terra-Petra can prevent these vapors from intruding into your structure.

Our Vapor Intrusion Services:

Phase II Investigation

Phase II Subsurface Investigation assesses whether the Phase I identified historic on-site or off-site hazardous uses have impacted the soil and/or groundwater conditions.

Subslab Depressurization

We have both active & passive SSD design capabilities, and will coordinate with the project architect, civil, structural, plumbing, HVAC and landscape architect to deliver a design that meets your site-specific conditions.

Soil Gas Characterization

The data obtained from a soil gas investigation can identify the source and spatial distribution of contamination at a site or estimate indoor air concentrations for risk assessment.


Offering the ability to identify, monitor & report along with several methods for proper removal and disposal of soil and ground water contaminants per agency accepted standards.

Mitigation Design

Terra-Petra routinely designs both passive and active Building Protection Systems across numerous cities and counties governed by many different agencies.

CQA/CQC Monitoring

Starting at the pre-construction phase, we work with all agencies and contractors to establish an acceptable guideline for installation of the systems – as well as monitoring, documenting and reporting our findings.

Vapor Intrusion Consulting

Terra-Petra is conversant with the many laws, codes and regulations at the city, state, county and national level. We understand the testing, design, monitoring and reporting procedures for many different regulatory agencies.