So many factors can affect a parcel's value including topography, soil quality, zoning, history, utility access, road access, shape, etc.

Well, at first glance it appears to be human excrement, BUT the bowl on top of the tank indicates that a person has "created" a mess by filling the toilet and mounding it up with soil from the backyard, which explains the bowl used to transport it into the house.  

Our mailers to facilities with managers often never make it to the owners because the manager takes one look at it and thinks, "I don't want my job to be sold out underneath me!"

Also, ask the neighbors (if there is any) about the soil.

I mean you can't just up and move your farm, the well you dug, the soil you improved, etc...

I Highly recommend asking if he has any soils reports, surveys and any engineering reports for the property.

Add non-porous soil.5.

They are from the DFW area and know the soils, etc.  

They also have a sister company called MLA Labs that can do soils tests to aid the structural engineer in designing a proper solution for the problem.  

A nuclear attack on U.S. soil would surely mean the end of that country forever.