I guess you could use some judgement and look at the use of the dirt in question. If this was going through areas that are used like a typical back yard, col 4 probably applies. If this is some common area that gets used like a commercial site, park or playground it would be col 1.
It is certainly column 1 if this is going through a flower bed maintained by the landscape guys. I might even "suggest" pipe in there.


Greg Fretwell