There are variety of greywater home systems, from simple “Laundry to Landscape” systems, gravity fed designs that include shower, tub and sink water being diverted into a branched drain irrigation system, to more complex systems include using pumps and filters for automated drip irrigation The average homeowner can reduce up to 40% of their water use with greywater systems. A well designed greywater system meets California codes, reduces the amount of potable water going to the garden, and allows household members to easily choose when they want greywater to go into the landscape or into their existing sewer or septic system.
Laundry to Landscape (L2L)
The L2L concept was pioneered by Ecological Designer Art Ludwig (Oasis Design) and is now one of the most used and simple systems to recycle your laundry water directly to the landscape. It uses the pump in the laundry machine to transport the greywater to the garden, and can typically water 8 fruit trees or other perennial plants. There is a diverter valve installed so the residents can choose where the water goes: to the landscape or to the septic or sewer.
This type of system is easy to adjust flow levels to different mulch basins, works best on level yards, and needs very little maintenance. This system does not need a permit and most handy people can install them, following 12 simple guidelines that are in the 2013 California Plumbing Code. Greywater Corps also has an online article going over how to install your own L2L system in detail.
A branched drain system is a gravity fed system from a bathtub/shower or sink. A diverter valve is installed and the greywater is redirected to the landscape. Depending on your site layout and topography drain lines from the house it can feed up to 8 mulch basins. Once a year maintenance of gathering composted mulch and replacing with new mulch.
Pump and Tank
This type system is used when you can’t use gravity to water your plants. If your house is below where you want to water, a surge tank with a pump can get your greywater uphill and spread it out to more plants. The water is never stored more than 24 hours or it will start to become black water! It requires access to the plumbing, room for the tank and electricity to power the pump.