Question
We recently removed an above-ground pool from our backyard.  The previous owners mixed something (lye?) with sand to for the foundation for the pool.  The compound broke up in lumps, similarly to what one might expect from a low-compressive strength concrete.  We want to grass to grow where the pool used to be, but we want to know what else we may need to do to get that to happen.  All recommendations are appreciated.  Our zip code is 70168.

Answer
If I'm understanding correctly, you've got a pretty simple, yet difficult situation. The compound you described is going to have to be removed, and good topsoil needs to be brought in. It'll be a bit of a pain, but it will be far, far preferable to spending a few seasons with little to no grass while you try to coax growth from a bad situation.

Remove it all, then bring in the good stuff.

Good luck!

-C.J. Brown
www.TheLawnCoach.com