How deep?

[kc2006]

Got a call for a job clean up where an above ground pool was and seed the area. I've never messed with areas that had pools before so I checked and theres about 2" of sand and a good 8" of what appeared to be like an ag-slag or stone dust type material under that. I'm wondering what you all would think would be a good enough depth to clean out and then backfill with good top soil? I was thinking 4" would be good. But what do you all think?

[Runner]

To make it short and simple, yes...I would say a minimum of 4 inches. A bit more would be better. I would like to see some more drainage there. As a matter of fact, if you were to grade the slag off to an angle (or sharp crown), that would be better for some drainage.