The contractor brought in another bobcat and truck to remove and haul the topsoil.
They ended up having to remove more soil than was originally planned, because back in 1978 .. when the house was built ... they weren't in the habit of seperating the topsoil and clay. The result was a real mix of fill.
Not a good thing. Apparently loam (topsoil) absorbs too much moisture, which freezes, expands, and causes heaving ... which leads to a cracked garage pad.
They ended up trucking out 6 or 7 loads of soil, and will now have to add more crushed rock fill in order to properly support the garage pad.