Figure 1.4: For a different interpretation of the subsurface the resultant contaminant plume is distinctly different than the one shown in Figure 1.3, even though both realizations exactly honor the data. For the given data, both descriptions are reasonable, and neither is likely to be exactly correct. Comparing Figure 1.3 and 1.4 demonstrates why it is important to evaluate multiple descriptions of the subsurface. Without doing so, the risk involved in defining the contaminant distributions and levels cannot be assessed.