If your site is suitable, you can also use a gravity discharge option, removing the need for any pumps. For gravity to work, you will require a fall of at least 3m from the top of the system to the start of the disposal area; our slope calculator can help you work out what fall you have.

The black water drainage includes your toilets and kitchen sink, all the rest is grey water (laundry, showers, basins etc.). This improves the performance of the system by reducing the amount of liquid passing through the worm bed (they like to be damp, but they’re not into swimming). It also keeps laundry powders and other chemicals out of the worm bed, protecting them, and giving you more flexibility around which products you can use.

It can discharge via LPED or subsurface, ETS bed, soakage bed, conventional trenches, mounds, sand trenches and arches.