The focus of environmental remediation has historically been on groundwater protection. Over the last 10 to 15 years, that focus has shifted to include vapor intrusion (VI) mitigation, particularly of solvent and gasoline vapors, which are common concerns at numerous sites throughout the United States. Dry cleaners, gas stations, and manufacturers using volatile organic solvents are common sources of contaminant VI into indoor air. The VI issue is hardly a new phenomenon; however, with recent advances in our understanding of chemical toxicity (especially with certain chlorinated hydrocarbons, such as trichloroethene [TCE]), VI has become a driver for many site investigations and an impediment to approvals for site closures by regulators.
This article will cover VI basics, mitigation methods, and keys to successful mitigation.