"TonyK" wrote in message
...
We have an old septic tank, ie. big concrete box in the ground, half
settlement tank and half clinker.

The tank is well past is useby date and we've just discovered the original
drains are failing etc. I'm looking at a £3K bill just to get the damn
thing
emptied due to its location.

Heres the plan... re-divert existing main drain 30m to a 4500l Klargester
style onion from which the grey water runs through another drain to the
original tank (once emptied).

The theory is I'll have a a proper Klargester doing the seperation and the
original tank then "filters" the grey water even further and in theory
never
needs emptying again (hope/pray).

Sort of a double tank system with the Klargester emptied quarterly.

BTW , based on the FAQs 180L per day I need (180x70x300)+(180x8x300) =
3.9m
L... since our water is metered I know we only used 1.5m L last year so I
gues this is more accurate? Rain water runs off through land drains.

A BioDisc is out of the question. Have been quoted £40-50K. I can do this
system for under £10K including the emptying!

Any thoughts, observations, obvious flaws?

Ta

You have the best now, the modern equivalent is the Albion which consists of
two parallel concrete rings which goes to soakaway.

1. What I would do I would re-do the spreader, empty the tank, and it will
be as good as new. The reason the spreader has failed is because the tank
has not been emptied regularly. Empting depends how thick is the crust in
the primary tank 18" is max.

2. The alternative is a reed bed system. SepticTank to reed bed tank 1, to
next reed bed, then to discharge to pond with fish or ditch or river. The
Environ Agency (EA) love reed beds.

In my system I have permit to discharge to ditch or river, my system is for
10 people. I have Albion going into 2 small reed bed tanks then to pond
overflow to open ditch. I scoop out the crust every 2 years as I need the
grey water to feed the reeds. The fish in the pond love it, the water was
checked, for the first year by EA, and they don't come any more. I built it
all 7 years ago and its perfect. Permit is for life of system.