Sacha wrote:
On 2009-05-08 20:55:06 +0100, K said:

Sacha writes
On 2009-05-08 08:40:42 +0100, Andrew May
said:

There is a little area of my garden in which nothing has ever grown.
I have known for a while that if I dig more than a couple of inches
down I come across bricks. A neighbour tells me that this area used
to be a chrysanthemum farm and I have always assumed that these
bricks were the foundations for a greenhouse of some description.
Last weekend I took the opportunity to dig further with a view to
finally getting some garden that I can grow something in. I now
think that what I have is not the foundations of a greenhouse but
am at a loss to explain what it is.
snip

My Nurserymen husband and stepson (Essex in the past, Devon now) both
say what you have there is a bog garden. In the - er - vernacular.

That was my immediate thought. But if the OP is right in his hunch
that it was built at the same time as the house, isn't 1948 a little
late to be building houses without inside toilets?

It's a triple chamber septic tank, according to Matthew, who reckons
that the nursery that was there was probably built in the days before
mains sewerage was available. Had it been actual loos, it would have
been a block for the nursery workers.

Full marks for everyone who identified it as a septic tank. Based on the
information provided here I excavated further to the left of the first
chamber and came across what can only be described as a standard
inspection chamber. Straight through with a pipe from the house and
exiting into the first tank. I have added photos for the benefit of
anyone not by now terminally bored by this thread.

The one oddity is that the pipe that I thought was the inlet to the
first chamber in fact comes from above the water level in the inspection
chamber and the inlet to this is blanked off with a clay disk sealed
with pitch. This all seems to be a single piece of ceramic so I assume
it is intentional. Is it some sort of safety valve in the case of
exploding gasses?

Thanks for all your help. Now I know what it is I can start dismantling
it and planting the garden.

Andrew