This is one in a series of newsletters dealing with drilling and sampling technologies. For more information please refer to the newsletter section in our web site www.amiadini.com.

Environmental Investigations – Soil Gas Surveys

Soil gas surveys can be a useful means of identifying contaminant source areas. The primary applications for soil gas surveys are where the location of the contaminant source areas is unknown.

Soil gas surveys collect soil gas from a hollow probe driven into the ground.

These samples can be analyzed on site utilizing a mobile laboratory.

Or, the sample can be sent to a fixed laboratory.

A quick qualitative evaluation can be obtained by utilizing colorimetric tubes.

A colorimetric tube is also known as a "length of stain" tube: the concentration of the chemical being tested produces a color stain in the analytical material — the stain length being proportional to the concentration in the air. A tube is selected for the chemical to be measured, the ends are broken and the tube is inserted into the pump. The material inside changes color and the length of the stain is read against the scale to give the concentration.

Active soil gas data analyzed in the field is realtime data and the scope of the survey can be adjusted to pinpoint “hot spots” and collect additional data during one mobilization.

The results are plotted on a diagram and lines of equal concentrations isoconcentrations) are drawn, enabling to spot the source location.

Active soil gas surveys are not suitable for low permeability soils (e.g., clay) or very shallow water tables.

Clayey Soil

The information in this newsletter has been gleaned from various web sites. Acknowledgements are made to US EPA, EST Inc http://est-inc.com, US Geological Survey (USGS), ISHN www.ishn.com, and Cardinal Professional Products www.cardinalproproducts.com.

Call me if you've got any questions. There are no obligations.

Ami Adini
Ami Adini & Associates, Inc.
Environmental Consultants
Underground Storage Tank Experts
323-913-4073; 323-667-2336 fax
mail@amiadini.com
www.amiadini.com

Ami Adini is a mechanical engineer, California Registered Environmental Assessor, Level II, and president of AMI ADINI & ASSOCIATES, INC. (AA&A), an environmental consulting firm specializing in all phases of environmental site assessments, rehabilitation of contaminated sites and upgrading of underground storage tank facilities. AA&A supplies practical solutions to environmental concerns using the highest standards of ethics and integrity while providing its clients with maximum return on their investments.