Hi

Thanks for all your advice. We have a septic tank and I was pretty
sure that the drain went into the tank - however, I will double check
as I don't want to drain it away anywhere else. Is it very unusual for
top water AND foul water to go to the septic tank?

To make absolutely sure I could run the outflow to the drain from the
kitchen (sink/dishwasher - on the presumption that this WILL go to the
septic tank). However, I would still be faced with the same problem. I
cannot run the outflow above ground to the top of a gulley because it
crosses a path around the house. Would I therefore have to extend the
drain?

Cheers again

Ben