I'm having issues trying to constrain a modeled contaminant plume within 1 stratigraphic unit. To set the stage: the strat unit is dipping 40 deg to the west and 90% of the contamination is found within this unit. The water table is the upper limit, however (issue #1) when I create the water table surface it plots 4000ft below land surface (I tried plugging in depth bgs as well as elevations for water table and neither will plot correctly). Is there a way to create a planar surface to act as the water table at a specific elevation thus acting as my upper surface data filter (spatial (xyz) filtering)? Next, I've constrained the I-data model in the strat unit (dipping 40 deg) via upper and lower model constraints (top and bottom grids of my strat unit), but when I run the I-data model the whole strat unit becomes "contaminated" not where I know it to be (near the surface exposure to a depth of ~100 ft) (I have high fidelity and Logarithmic selected), the high concentration areas are in the correct location, but according to the model the entire unit has 100ppb. Lastly, my stratigraphy model looks o.k. near the surface (bedrock dipping correctly, appropriate thicknesses, etc.) but at depth everything becomes planar. How do I tell the software that beds that dip at the surface continue to dip in the subsurface?