On Sun, 8 Apr 2007 21:11:55 -0700, "Steve B"
wrote:


Call up your local municipality, or find someone who can give you the answer
to what it is. Opinions here are free and worth twice that. Someone in
your area can give you some real time info.

I have not seen one in my part of the country, but I am not so stupid as to
say that they are not necessary in yours. It could have to do with water
table levels, soil compaction, some special septic tank vent, percolation
rates, or many things that if you go changing, might come back to bite you
hard in a sensitive place.

I think I finally recall seeing a 2 or 3 of these over the years, and
they weren't in anyone's yard. So maybe it has nothing to do with his
house. I have the most vague recollection one being near long
distance gas lines, but I could be wrong or that could be a
coincidence.