Soil vapor extraction is a remediation method that uses vacuum extraction to remove volatile organic compounds from contaminated soils above the water table. It works by applying a vacuum to induce volatilization of organic compounds and metals from the soil matrix. While effective, soil vapor extraction is influenced by factors like soil permeability and moisture. It is generally more successful on lighter petroleum products like gasoline but can remove heavier contaminants like diesel or kerosene when combined with in-situ thermal desorption.

1. Soil Vapor Extraction -
Description and Application
By Mehrdad Javaherian

2. Introduction
• An environmental epidemiologist and engineer who has
worked with such organizations as the California Department
of Public Health, Dr. Mehrdad Javaherian currently serves as
a Principal Consultant with Endpoint Consulting, Inc. and
directs LRM Consulting's practices in California. Dr. Mehrdad
Javaherian consults on a wide range of environmental
remediation services to both the public and private sectors,
including in-situ thermal desorption for which he holds
multiple patents, and soil vapor extraction.
According to the Environmental Protection Agency (EPA), soil
vapor extraction, also called vacuum extraction or soil
venting, is a remedial method that reduces quantities of
volatile components in petroleum products in soils in the
unsaturated zone above the water table.

3. Soil Vapor Extraction
• Coupled with in-situ thermal desorption which
induces the volatilization of organic compounds and
select metals from soils, soil vapor extraction
technology effectively removes and/or lessens
concentrations of volatile and semi-volatile organic
compounds by applying a vacuum to a contaminated
soil matrix.
While the soil vapor extraction process has been
proven effective, there are a number of factors that
influence its efficacy, such as soil permeability,
depth to groundwater, soil moisture, and soil
stratification.

4. Conclusion
• The EPA notes that soil vapor extraction is
typically more successful if used for light, and
thus more volatile, petroleum products like
gasoline. When applied alone, soil vapor
extraction doesn’t effectively remove heating
oils, diesel fuel, and kerosene as they are heavier
and less volatile than gasoline; however, when
coupled with in-situ thermal desorption, even
the heavier-end contaminants are induced to
volatilize, allowing for removal via soil vapor
extraction.