Soak-aways plus grey water

[SimonTown]

Hi,

I have a septic tank, which due to an old/non-functioning soakaway backs up regularly.

I am looking at having a new soakaway dug, but was thinking of separating the water from the toilets and the grey water. I.e toilet water to septic tank, washing machine, baths, dish washer to a separate soakaway. Idea being to take the pressure of the main system.

My questions are:

1. Is there any regulation which forbids me from taking the grey water straight into a separate soakaway?, and not via the septic tank

2. What type of soakaway would you suggest for septic tank, and grey water, (in sandy soil), rings, crates, rubble?

3. Would this be a sensible option?

Thanks


Simon

[seanandruby]

bath waste, sink and dishwasher waste in my estimation should go with the foul. skin, hair food would in time silt up a soak away, not to mention cause vermin. my vote would be to run it all into a septic tank.

[Dave_L]

Agree with you Sean.

[flowjoe]

Sean is of course correct it should run to a septic tank unless you install a gray water system that treats it before you re-use it.

Separating the systems will cost a fair bit, you should concentrate on why your soak-away has failed unless you are serious about installing a gray water system to re-use the waste water.

What kind of septic tank have you got ?

[SimonTown]

The system was built around 1930, and starts with a large tank, and is followed by a klinker chamber, from which the soakway should be getting rid of the processed effluent.

I think the soakaway may have been replaced previously as the invert level is very high, in fact may be above the klinker!

I have a friend who runs a large groundworking firm and he has kindly agreed to help with the replacement. However, I have already suffered a failed attempt to rectify the problem and want to be sure I have a little more knowledge this time!

What types of soakaway would normally be linked into the chamber?

Thanks


Simon

[flowjoe]

If the outlet is above the clinker you will not be getting any benifit from it, are there dip pipes on the main chamber? or baffle walls to prevent solids and grease passing through the tank.

You need the main tank to be working properly before you throw money at the soak-away, perversly sand can be too fine for a soak-away grease, fat and fibres can seal the sub-soil.

A soak-away can consist of anything from 50mtrs to 100mtrs of perforated pipework surrounded in granular fill depending on the size of property and the use it gets.

[SimonTown]

Hi,

There is a dip pipe on the septic tank, but I think I'll extend it when I get the new soakaway as I think some solids are getting through.

The idea of 100mtrs of pipework is a bit of an issue, as I really don't have that amount of space, would a ring-based or crate based soakaway be a viable alternative?

I appreciate I won't be able to cover the same area, but would struggle otherwise.

Thanks


Simon

[Tony McC]

A crate-based soakaway in place of a leach field will only work if you have a highly permeable soil. You need to test the percolation rate before deciding how to move forward.