Design of septic tank and soakpit
The drained vertical sand filter is designed for soils with too low permeability. The washed sand is used as a purification medium. Wastewater is treated by infiltration into the filter.
Begin with an on site analysis of the soil by a qualified elevator. A low pressure pipe system may overcome soil and seasonal high water table challenges.
If a soil based system proves infeasible, consider a facultative lagoon or recirculating sand filter.