A prototype laboratory model to predict TCE contamination of residence basements from polluted ground water

Abstract

The widespread pollution of ground water by volatile organic compounds has led to the possibility of contamination of residences by migration of these compounds through the soil gas. Recent studies indicate that the pressure gradient existing between the soil and substructure is responsible for a large portion of soil gas infiltration into basements.

This article describes a laboratory model which can be used to simulate a ground water system flowing beneath a basement structure, which is under negative pressure. Concentrations of trichloroethene (TCE) in the basement were found to be approximately 3 orders of magnitude less than that in the ground water, which is in the range of results found in the field. The model can be used to study the mechanisms involved in soil gas transport, and the effects of a pressure field on vapor flux. These results may also be helpful in calibrating mathematical models predicting levels of pollutants in residences overlying contaminated aquifers.

Key words:

• Ground Water
• Trichloroethene
• Indoor Air