The Brew Cabin

Posted: **Sun Jun 01, 2008 10:26 am**

I will be putting a new septic tank soakaway area on my property as the old one cant cope with the amout of water being pushed through the system and is also it is a bit clogged up. Fortunately I have got plenty of well draining land and sloping away from my house towards open fields.

I have read up about the general spec required from this and other web sites but there are a few things I am unsure about.

(1) What is the best stone to use? Basically what should I ask for when I order this stuff? Is the 20mm pebbles used to mix concrete OK or should it be something bigger?

(2) Would you recommend using geo textile on the top of the trench only or on the sides of the trench as well to stop soil from the the trench sides collapsing laterally and silting up the stone when in use?

(3) Would geotextile itself ever clog up with a constant flow of small water bourne particles from a septic tank outflow?

Posted: **Sun Jun 01, 2008 10:53 am**

.....in case I have confused anybody its not really a soakaway as such I suppose.

More of a closed loop drainage field spread over a large area via stone filled trenches and slotted drainage pipes.

....so hell of a lot of stone required as the trenches could be as wide as 900mm and will need about 450mm of stone deep. That makes About 0.4 cubic meters of stone per meter of linear drain!

Posted: **Mon Jun 02, 2008 8:52 pm**

It's known as a leach field.

Follow the advice on the main website. Ask your local suppliers as to what clean stone is available locally at a sensible price. Use a decent geo-textile to envelop the whole drain, not just the top.

Posted: **Tue Jun 03, 2008 11:34 pm**

Tony

Thanks for the advice.

Looks like it's gonna be a messy job connecting new drainage to the septic tank outlet as the existing very old drainage field starts pretty much right by the septic tank outlet having done a bit of digging. Basically its going to be difficult to locate the existing pipes which are somewhere under broken bricks topped off by plastic and which is flooded right to the top of the plastic.

Is it possible to do a quick fix to ease the existing overloaded system by using Land Drainage techniques to provide new drainage spurs off the existing boggy ground where the water is breaking surface? i.e. dont bother connecting directly to the existing drainage.

Posted: **Wed Jun 04, 2008 6:04 am**

You might aswell do the job properly Lloyd and connect to the tank.

Posted: **Wed Jun 04, 2008 10:46 am**

Guess you are right Dave but not looking forward to it!

Posted: **Wed Jun 04, 2008 6:45 pm**

Get the tank emptied the day before you start working on the system, pump out the remainder of the waste water from your trenches and buy yourself some time to play.

It may be possible to sonar trace the existing pipework in order to find the end of the system, you can then extend it at will.

P.S - Don`t bite your nails and get the Mrs to feed you with a catapult at dinner time

The Brew Cabin

Spectic tank soakaway - ....up the creek without a paddle