I'm not sure if it's a matter of hiring a crew to cleanup the site and then build as normal, or if there will be some nightmare of red tape, soil remediation or who-knows-what kind of obstacles.I'm sure i could ask the listing agents for some information but they are hardly impartial so I wouldn't want to rely on that. 

Carpet cleaner stated that carpet was so deeply soiled, stains could not be removed with a steam cleaner.

My overall point is this:  real estate, land, soil, whatever you want to call it is the only thing you should be putting cash into.  

These would include not allowing dog to dig in yard, no damage or soiling in the house, house/potty trained, etc.

Great advice @Sandy Sawyer! 

When you say North Atlanta, do you mean outside the perimeter (Marietta/Sandy Springs and up) - aka Cobb, Cherokee and Bartow Counties?

@Sandy Sawyer Absolutely true.

That looks like shrink swell soil issues.

Soil tests, aquafer tests, etc? 

@Sandy Sawyer Congrats on the 3rd house this year, that's awesome!