Kitchen Sink System- Branched Drain

Goals: To replace freshwater irrigation with greywater irrigation.

Site description: Easy to access crawlspace, yard sloping towards the front. At this site, the shower and washing machine greywater pipes were much harder to access than the kitchen sink.

Fixtures and output One person using the sink, around 10 gallons per day.

Cost:  1 1/2″ – 2″ 3-way valve $40, double ell fittings- $24, other fittings- $50, pipe- $10 Total materials: $124

3-way diverter valve

pipes to outside

pipe along house (will be painted to protect from sun)

Greywater flows through 1 1/2″ ABS pipe, dropping at 1/4″ per foot, and exiting the crawl space through a vent.

Flow is divided by a ‘double ell flow splitter’.

Outside the pipe continues to descend, splitting once as it drops down a step. Half of the water goes to the right side, half to the left side.

The water on the left irrigates a pomegranate bush.

On the right side the flow is divided once more, irrigating two blueberry bushes and one pineapple guava shrub.

Kitchen sink greywater comes out of the pipe, falling into the mulch basin. The outlet is covered by an irrigation valve box. Any food or particles will catch on the mulch and compost. Earthworms love the outlets of kitchen sink systems!

• Specifications and Notes: Since there is not very much water the flow is only split two times. The ABS pipe will be painted to protect it from the sunlight (the sun will degrade the plastic over time).
• Maintenance and trouble shooting: Checking on mulch basins, annual addition of mulch and removal of composted food.