Evaluation of a BTEX Plume in Fractured Crystalline Rock in the Georgia Piedmont

Proceedings of the 1999 Georgia Water Resources Conference, March 30 and 31, Athens, Georgia.Water flow and chemical transport in fractured media has become a major concern in recent years. Traditionally, these problems have been viewed and modeled as flow through pipes. However, this approach is limited because it is very difficult to predict the orientation, size, and length of the fractures, hence the direction and velocity of the petroleum hydrocarbons. Groundwater sampling of saprolite, residential, and bedrock wells at a site near Danielsville, Georgia has revealed the presence of petroleum constituents in the aquifer system beneath the site. The site has a documented history of spills over the past thirty years. Groundwater sampling of some of the residential and monitoring wells in the vicinity of the site has indicated benzene contamination ranging from non-detectable to approximately 2500 parts per billion. It has been established from groundwater samples collected from bedrock that contamination has migrated from the saprolite into the fractured bedrock aquifer. A suspected pathway of contaminant migration could possibly be an improperly cased bedrock well. Physical and chemical conditions at the site have been modeled using a three dimensional visualization program. In this paper, we show how the use of this tool leads to understanding of the fracture flow system, and how this knowledge can be used to prepare a more comprehensive, physically based fracture flow model.Sponsored and Organized by: U.S. Geological Survey, Georgia Department of Natural Resources, The University of Georgia, Georgia State University, Georgia Institute of TechnologyThis book was published by the Institute of Ecology, The University of Georgia, Athens, Georgia 30602-2202 with partial funding provided by the U.S. Department of Interior, geological Survey, through the Georgia Water Research Insttitute as authorized by the Water Research Institutes Authorization Act of 1990 (P.L. 101-397). The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of the University of Georgia or the U.S. Geological Survey or the conference sponsors