Septic tank.

The traditional septic tank is a single chambered box with an inlet and an outlet pipe and the effluent trickles (discharges) out of the septic tank into a system made up of trenches roughly 400 mm in width. The effluent is slowly absorbed and filtered by the ground around the trench (called the disposal field) before becoming groundwater moving to ponds, lakes, streams, rivers, and eventually the sea.

Effluent Disposal.

Effluent disposalSeptic tanks should dispose of the effluent into the soil in a safe and environmentally friendly manner.

The soil is used to remove harmful bacteria and other organisms present in the effluent from the septic tank. This treated effluent is then able to gradually enter the natural groundwater system without polluting it.

However, many traditional septic tank effluent disposal fields have failed in use and had to be replaced or upgraded. This has lead to contamination of water used for human consumption because septic tank effluent was entering the ground water directly without treatment.