Jasper Vrugt, LANL / Earth and Environmental Scie, LANL / Earth and Environmental Sciences Division, Mail Stop T003, Los Alamos, NM 87545
Multiple tracer experiments with different transport properties hold great promise for recovering detailed information on subsurface flow and transport processes and parameters, but only if robust methods for modeling the results are developed. In a previous paper we presented a combined parameter and state estimation method, called SODA for improved inverse modeling of subsurface flow and transport parameters, and demonstrated its utility for modeling the breakthrough curve of a single tracer. In this paper, we extend the methodology to transport modeling problems involving multiple tracers, coping with the issue of potentially conflicting information about the underlying transport system based on the behavior of the different tracers. We illustrate the effectiveness of this extended SODA approach by modeling a multi-tracer experiment conducted in fractured volcanic tuff in the saturated zone near Yucca Mountain, Nevada.