Where to get soil to fill a raised vegetable bed
I'm wondering where, near Marietta, to get soil to fill a raised vegetable bed. I'm not going to have enough native soil. I figured I'd mix top soil (if I can find some of good quality) with mushroom compost. Or perhaps mushroom compost and Natures Helper would do well. Or maybe someone has already come up with a good mix that can be bought in bulk.
When I lived in Augusta long ago, there was a man who made huge quanities of compost down by the river. We took a truck down there and bought a load at a very reasonable price, but I've never found a place like that here in Atlanta. I heard that Cobb county composts it's garbage and gives it away, but I'm nervous that it might contain heavy metals that would be unsafe for vegetable gardens.
Does anybody have any ideas?