Underground system in which sewage is treated and dispersed.
Land containing perforated pipes through which the water infiltrates the ground.
Perforated pipe through which water drains in order to filter through the gravel and then into the soil.
Device spreading water evenly through the network of drains.
Bed of small stones absorbing smaller particles found in water to prevent them from blocking the perforated pipes; it also keeps the perforated pipes in place.
Wastewater settles and sewage decomposes naturally in the first compartment. Water then flows into the second compartment.
Drainpipe carrying wastewater from the waste stack to the sewage system or septic tank.