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Goals: To replace freshwater irrigation with greywater irrigation, give more water to the garden, and save time.

Site description: This single family home has an in-law unit in the backyard. The house and in-law share the washing machine. They do up to 6 loads a week. The system irrigates are two lemon trees, and two raised veggie beds in the back yard and one fig tree and japaneese maple tree in the front.

Fixtures and output: One top-loading washing machines, about 40 gallons/load, about 6 loads a week= 240 gallons/week

Cost: about $200

System description:

3 way valve

The brass three-way valve is to the left of the washing machine and the auto vent is located out the window.

Backyard garden and house

The center of the yard has three raised beds, two of which are irrigated with the greywater.

Drilling 1/4 inch holes in

1/4 inch holes are drilled on the bottom facing side of this 1″HDPE tube. The tube is laid down the middle of these narrow raised bed to distribute greywater. The bed was mulched with straw to cover the tubing. This part of the system will need to be cleared regularly since the 1/4 inch holes can clog. The end of the tube is open (not plugged), so if the holes clog all the water can still exit the pipe. This protects the washing machine from back-pressure.

Mulch basins are dug around the drip line of the trees. They will be filled with woodchips when the system is completed.

Greywater system from atop

Specifications and Notes: This system was installed during a remodel project. It will need to be removed when the house is painted. To facilitate an easy removal and reinstallation of the system unions were used so the pipe could be disconnect and reattached easily. Root crops can’t be grown in the garden beds irrigated with greywater.

Maintenance and trouble shooting: Annual checking and possibly replacing mulch, monitoring pipe in the raised beds, clearing out the 1/4 inch holes in tubing of lint.