Field Pile

I was told that Blueberries could be grown over this area, as the roots do not go deep, and therefore won't disturb the lines any. I wanted something to grow there other than grass that I would have to mow, and all that was growing there was weeds and Poke root, which does have deep roots. I ripped those out with a Rototiller last month. The problem I have is in the growth medium. Are these berries safe to eat if grown in this manner? I know some people put manure on their vegetable garden as part of their compost. I do not. I have a separate compost pile used strickly for non fruit or veggie bearning plants, and this works fine for them. I am not cognizant as to how deep the leech lines are laid in a typical configuration. Maybe, since the drainage is downward into the soil below the lines, that this doesn't present a problem with the shallow roots of the Blueberry. I just don't know. Any help would be appreciated.