fig5 2

4

3

Key
A	five trenches	3	Distribution pipę
B	three trenches	4	Infiltration pipę
C	two trenches	5	Sand layer
1	Connection pipę	6	Distribution layer
2	Distributon chamber	7	End connection with ventilation and access

tVi Natural ground width between trenches > 1 m W₂ Distribution layer width 0,5 m to 1,5 m L, Distribution layer length < 30 m Area =1 (L, x W₂)