I referred to a book called 'Create an oasis with Greywater' by Art Ludwig which I have had for some years and never read until now.
In France there is currently no legal system for greywater outlets and dry toilets - the permitted systems are for grey and black water combined - all very expensive. Pedoepuration can be extremely simple to install and very low cost.
fruit tree. You can see the greywater channel from the house in the foreground
Left: Testing the perk rate by digging a hole, pushing a graduated stick into it, filling it with water then noting how long it takes for the water level to go down a given amount. A very fast or slow perk rate is not good for this system. Fortunately here, although the ground is heavy clay, the perk rate is not too slow.
Below: You can see the pvc collection grey water pipe coming out of the house. We built a 'regard' using boards to shape concrete with a sloping base and with an outlet for a smaller pvc pipe to go to the fruit tree basin with a slope of 2%