Percolation test fail - sewage options?

[saveasteading]

3 minutes ago, ProDave said:

The USP of the puraflow seems to be you don't need a soakaway, it will just drain into the space of the ground it occupies.  Building control here did not agree with that

Correct by the BCO.  Nonsense by Puraflow.

If the ground can't absorb it, then it will overflow and run on the surface. Puraflood.

The volume isn't high, but still has to be catered for.

 

 

4 minutes ago, ProDave said:

20% less area of soakaway for a treatment plant vs a septic tank.

This is a remnant from when treatment tanks were a new thing. Septic tanks  emit a still filthy but very active liquid, and the vast area of the gravel surfaces allows it to cling to gravel and degrade,

They allowed a very ungenerous 20% reduction in area for properly treated water.I designed for this and we installed phase 1, but we haven't got round to Phase 2, and the BCO still says he has never seen as much as we put in.

 

I've looked at the liquid coming out of modern tanks (I've done 4, I think) , and it looks clean and doesn't smell. They have rightly stopped suggesting you could drink it though!

 

[saveasteading]

23 minutes ago, ProDave said:

Building regs in Scotland at least allow you to have about 20% less area of soakaway for a treatment plant vs a septic tank

I've looked again at the English reg's. My interpretation is that the huge drainage field only applies to septic tanks, and that treatment plant outflow does not need further treatment. ie not 20% reduction but 100%.

It doesn't say that it is not necessary, but the drainage field is applied only to the section on septic tanks, It is silent on the matter in the treatment tanks section other than that outflow must be 10m min from  building or watercourse. That fits with the @ProDavelogic above.

 

That's certainly what I've worked to before in England. I think the 20% thing used to apply but has disappeared at some stage.