Q: I recently had a water well drilled in a pine island. Now I need to remove the granite sand and sludge. Can this material be used to fill low spots and truck tire trenches? Richard H. Soard, East Cobb
A: I don’t believe there would be anything toxic present. The drilling residue is composed of pulverized granite, drillers slurry (a type of clay) and maybe metal particles from the drill. If there is a high percentage of clay (bentonite) in the material you’d have a hard time getting anything to grow in it without mixing it with a lot of soil conditioner. I’ll leave it to your good judgement to determine if you can make anything useful out of the leftover sludge.