On 6 Sep 2003 18:47:23 -0700, (Pen) wrote:

Interesting oxymoron: 'clean dirt'.

Not so. In these days of toxic everything, it might have to be
certified by chemical analysis, but presumably means homesite dirt
without construction rubble, weeds & seeds, or recent chemical
contamination. OTOH, it could mean sand. My mother, who grew up in the
east, always qualified the fine dust that blew into the house in New
Mexico as "clean dirt" in that it could simply be vacuumed up and had
no traces of oil or coal dust.