Hi Guys,
As I got into that pile further I found what looked like fiberglass cloth and it had spread all over the ground from working the pile. When you crushed it in your fingers, it turned to white dust. If you picked it up, white powdery like dust filled the air.
Needless to say, that made me rather concerned. It wouldn't burn either. So I got out some brand new fiberglass cloth I have and tested it and it wouldn't burn either. That was good news because then it was possible it was fiberglass backing from the shingles and not asbestos. The thing is...I've never seen fiberglass powder like that when it gets old.
I took 2 samples to a lab today ($50) and it came back negative on asbestos. Was well worth the piece of mind it gave me.
But it goes to show that you need to be cognizant of what you could be digging up. I learned a valuable lesson and am very appreciative that you guys pointed out that there could be some nasty stuff in there. I've been wearing a cartridge respirator when I work. It helps keep the dirt/dust out of my lungs, too.
I'd need 10 dumpsters for what I had on hand. No, can't do the dumpster option. But I did find someone who wanted 30 yards of it for fill so now I'm down to about a half a pile!