[schreibdave]

I would dig up the sand. Your sod is going to want to root into top soil. Sand doesnt have the nutrients or water holding capacity of top soil.

 

[schreibdave]

I'm in northern NY so we don't have St. Augustine growing here. Maybe a southern grass would tolerate that sand. Our northern grasses would not be able to get enough water or nutrients from sand.

How did you end up with 6" of sand on top of your soil?

In terms of disposing of it you would probably need to hire someone to cart it away. In my neighborhood it would get dumped on one of the vacant lots and then bulldozed in to the soil when they go to build a new house.

 

[schreibdave]

You could try to get the concrete company to come back and get it. Good luck.