By: Pacowy On: Tue Jul 24, 2012 10:16 am
I wouldn't worry too much about contamination unless it's oiled. IIRC anthracite is used as a filter for some municipal water supplies.
I think the big issue is to make sure it's dry before the cold weather arrives - it can be a hassle if it freezes. Take delivery far enough ahead of time that it can dry out, and keep it well covered.
Mike