However our strawberry bed isn’t only what it seems to be….
It covers a highly efficient, self-contained, underground wastewater treatment system; a triple chamber DIY septic tank! A septic tank separates and processes wastes. From our domestic wastewater that flows into the tank, heavy solids settle to the bottom, forming a layer of sludge. Greases, oils, and lighter solids rise to the top, creating a layer of scum.
The traditional toilet of our house
The area between these two layers is filled with liquid effluent that can flow through the outlet pipe to the drainfield. The layers of sludge and scum remain in the septic tank where bacteria found naturally in the wastewater work to break the solids down. The layer of clarified liquid flows from the septic tank to the drainfield. The drainfield treats the wastewater by allowing it to slowly trickle from the outlet pipe out into the gravel and down through the soil. The gravel and soil act as biological filters.
It is a well-known system which we learned to design when studying Tropical Agriculture 15 years ago. I never knew that one day we would build one in a less tropical climate. To start the biological breakdown process in the tank you can buy all kinds of commercial starters but according to our former teacher a death chicken will work as good and the best solution was to put your mother in law in it!