On Jun 22, 8:25*am, dpb wrote:
harry k wrote:

...

Correct if you are referring to the _liquid_ level. *The 'cake' floats
on top. *Would water running onto the top of the cake penetrate it?
Dunno but the pumpers have to stir that up in order to suck it up.

Yes, but even if it didn't it would flow out the drain--it can't/won't
"stand" above an opening unless it is blocked.

And, there are two (at least) compartments--the exit is separated from
the inlet side by a baffle that reaches to the top so the solids are
retained there leaving essentially only liquid in the outlet chamber.
Otherwise the drain field would get clogged w/ solids almost immediately.

Still leaves the problem of enough water making its way through small
cracks to 'flood the the field'. *Then someone else already mentioned
the _fact_ that if ground water is entering the tank, the field is
already flooded.

Doesn't necessarily follow (depends on relative amounts of input versus
perc capacity of the field) but certainly large quantities of
groundwater should be prevented from entering the tank.

--

So explain just how "larged quantities" can enter the tank dthrough
very small unsealed openings. Seepage or maybe even drips are about
all you can get.

Harry K