I have to build a soakaway for the rainwater from our new extension (flat roof approximately 28m²). The soakaway will be around 6m from any building, the ground level here is approximately 0.7m lower than the ground level where the buildings are (ie, the garden slopes away from the house by around 70cm).
My problem is that the ground is very heavy clay (yellow/grey). Even after digging down for around 1.2m, it is still heavy clay. The house was built in 1974 and like all of the others on the estate, the rainwater is discharged into the foul drain (sewer).
However, the BCO insists that I cannot discharge the rain from the new extension in the same manner and a soakaway is a must.
Any suggestions as I just cannot see a "typical" soakaway working in this clay soil?
My problem is that the ground is very heavy clay (yellow/grey). Even after digging down for around 1.2m, it is still heavy clay. The house was built in 1974 and like all of the others on the estate, the rainwater is discharged into the foul drain (sewer).
However, the BCO insists that I cannot discharge the rain from the new extension in the same manner and a soakaway is a must.
Any suggestions as I just cannot see a "typical" soakaway working in this clay soil?