USE OF TRACERS FOR THE CHARACTERIZATION OF SCALE-DEPENDENT SUBSURFACE PROCESSES: INITIAL EVALUATION

G.R. Barth, T.H. Illangasekare, and H. Rajaram, Department of Civil and Environmental Engineering, University of Colorado at Boulder, Boulder, CO, 80309-0428, Phone: 303-492-6754, FAX: 303-492-7317


ABSTRACT Determination of the distribution and quantity of non-aqueous phase liquids (NAPL) in the subsurface requires accurate evaluation of the effective parameters governing flow in porous media. A great deal of the work done towards the development of effective parameters has focused on analysis techniques for adapting parameters determined from a small-scale to a field-scale system. These techniques suffer from the inherent limitations of developing conclusions about regional or grid-scale flow based on a limited number of smaller-scale, isolated measurements. A conservative tracer injected into heterogeneous media will, however, be affected by all the heterogeneities encountered in the existing flow-fields between the site of injection and extraction. A tracer test provides a direct measurement of the heterogeneous system. A series of tracer tests were performed to assess the ability of tracers to function as a tool for determining effective field-scale parameters. Experimental design focused on creating a heterogeneous system with known stochastic parameters which could be modified by NAPL entrapment. The analytical work concentrated on developing techniques to interpret the tracer test results.

KEY WORDS: effective parameter, tracer, scaling

This paper is from the Proceedings of the HSRC/WERC Joint Conference on the Environment, May 1996, published in hard copy and on the Web by the Great Plains/Rocky Mountain Hazardous Substance Research Center.


To view the entire paper, you must haveAdobe Acrobat Reader. Click here to download Acrobat.

Click here to download the paper. (118 k)


  
Send comments on the Great Plains/Rocky Mountain HSRC web pages to: hsrc@engg.ksu.edu; comments or questions about this WWW server, to: www@engg.ksu.edu.