The septic system is attached to a building in order to treat the greywater coming from the sinks and the blackwater coming from the bathrooms. The system is made of two septic tanks and six filtration chambers.

The septic tanks are concrete cylinders with a 10’ internal radius surrounded by walls made of ecobricks (plastic bottles filled with trash) bonded with a cement-based mortar. Toilet blackwater is first brought to the septic tanks where the solid and foam components are filtered. Each septic tank includes an air vent for degradation of the solid waste via air exchange.

The residual component of the blackwater is sent through filtration chambers. A filtration chamber consists of a 40” x 40” trench in the ground where different sizes of rock are laid in layers (from cobbles at the bottom to sand at the top). The trench is surrounded by plastic sheeting to avoid any water contamination of the ground. The blackwater is filtered through four chambers with similar compositions but different lengths before being released in a leach field on the East of the land.

The greywater coming from the sinks is brought to two grease traps before being sent to a common filtration chamber. From this chamber, the water can be pumped (manually or electrically) in order to fill bathroom tanks used for toilet flushes. If the chamber is full, it overspills into the fourth blackwater filtration chamber.

Finally, the system presents an additional inlet for an independent sink which has its own grease trap. Its greywater is filtered through a separate filtration chamber before joining the filtered blackwater via a junction box.