On Fri, 28 Jan 2011 10:24:39 -0700, Richard A Jones <Jones@COLORADO.EDU>
wrote:

>An option, which I haven't used, is to empty the smaller one in
>various BLM or FS pit toilets, every few days as needed.

Richard,
Except for the newer so-called "green" chemicals, dumping portable toilet
chemicals in a pit toilet will undesireably inhibit the bacterial action
needed for decompostion of the waste. The same goes for a toilet serviced
by a septic tank, though a small amount of chemicals will likely not do
much harm.

The good news is that pit toilets, which are nothing more than an outhouse
over a hole in the ground, are increasingly rare, even in the remote,wide-
open spaces in the West.  There are still a few here and there, but not
many at all.  The BLM and USFS toilets to which you referred are almost
certainly vault toilets, now usually prefabricated concrete structures,
often delivered in one piece ready to set on the "basement", which is the
vault.  These do not rely on bacterial action to decompose the waste, but
are instead pumped out periodically, so portable toilet chemicals will not
have an adverse affect on vault toilets.  However, trash in the toilet is a
big problem because it fouls the pump when the vault is being emptied.

Bill