Burn barrel? Little bit at a time? If you do it right, no smoke.
EDIT: On second thought, no. Assuming most of the wood is pressure treated. Burning it down to ash releases some of it into the air, and the rest will be concentrated in the ash, which is pretty much HAZMAT at that point.
EDIT: On second thought, no. Assuming most of the wood is pressure treated. Burning it down to ash releases some of it into the air, and the rest will be concentrated in the ash, which is pretty much HAZMAT at that point.