On Tue, 18 Sep 2007 11:03:03 -0400, Tom Del Rosso wrote:
"Chuck Harris" wrote in message

This is a common technique used in some septic tanks to give the
drainage field a break. The tank is broken into two chambers. The
first chamber holds the nasty stuff, and overflows into the second
chamber. The second chamber has a pipe that comes up from its
bottom, and performs an upside down "U" bend that goes back to the
bottom (inlet). When the tank fills enough to make the water fall
over the top of the "U" bend, it forms a siphon which draws all of
the water out of the chamber.

In the case of a septic tank, the pipe that forms the "U" bend has to
be sized small enough that a toilet flush will cause it to fill
completely and start the siphon.

So those low-flush toilets that people are forced to use might make their
tanks obsolete.


"Low-flush" toilets are a joke. They never flush properly, so you have
to flush them two or three times, so the net result is that they waste
_more_ water! I had an apartment in San Pedro, where they had modified
the ball valve/flapper valve, such that it would sink when the tank
got about half-empty. It didn't flush completely, so I got into the
habit of holding down the flush lever until it finished, which of course
defeated the purpose of the "water-saving" feature.

Cheers!
Rich