19 February 2022

BFG002: greywater bathroom

Tweaks to existing bathroom features to improve the way we use water.

• The sink basin drain plug is closed by default, and there is a lever that opens the drain for the duration of the time it’s depressed. When you turn on the tap, the basin fills with water that you can use for washing. Afterwards, you depress the button and the sink clears. You rinse the basin with the drain open to keep it clean.

• When you turn on the shower, fresh water initially fills up a recirculation system. This system sends water through the shower head, collects it from the drain, and filters it before sending it back through the head. The shower has a lever that can be pulled to use fresh rather than recirculated water. This fresh water displaces water in the recirculation system. When the tap is turned off, the recirculation system is drained and the lever automatically resets.

• Wastewater from both the sink and shower is stored and used to flush the toilet.

These concepts also apply in other contexts.