GREYWATER-Frequently Asked Questions:

Q&A about greywater with Lynne Latham,
ASID, LEED AP, Sustainable Design

Q What will it cost me to have a Greywater system installed?

A In the words of Art Ludwig, Greywater is all about context. What are your goals, how easy is it to reach is your source of water, do you need a pump or will your system be gravity fed, are you sending your water to just one mulch basin or irrigating several places in your yard? That being said, you should be able to do a simple system for under $100.00 and that includes high quality plumbing fittings, not necessarily a home depot job.

Q Can I do the job myself or do I need a plumber?

A That depends on how handy you are and your experience. You may need a plumber if your collection plumbing is hard to access or buried in a slab. With these “Laundry to Landscape” directions, you can probably do this yourself with the help of someone who knows about drip irrigation. You don’t want your plumber or the “blow and go guy” to handle your distribution plumbing.

Q Can I just attach a hose to my washer and water my plants with it?

A Not a good idea. Greywater is a health hazard when it is not dispersed of subsurface. Greywater becomes Blackwater in less than a week, not a pretty picture. What you can do as a very simple system is have a couple different mulch basins adjacent to fruit trees or ornamentals. You can then bury your hose a couple of inches into your mulch basin and move from tree to tree between washes. Obviously, this will be more labor intensive, the alternative is to use a branched system that uses drip irrigation to do the work. A word of caution about washing machine pumps: Don’t try to make your water go more than 3’ above the top of your washer or you may burn out your pump.

Q Do I need to use special soaps if I use my shower or washing machine as my greywater source.

A Yes, most soaps have a lot of salt in them and bleach has been known to kill a fruit tree in one application. Use a liquid detergent, stay away from Sodium chloride, potassium chloride is Ok, boron and borax are not. Dr. Bronners liquid soap is good for showers. The laundry soap that I would recommend is, Bio Pac. It was originally created by Art Ludwig, you can find it on Important distinction: Biodegradable just means that the product breaks down in Landfill. You want a Bio-compatible soap, which means that it is compatible with plant life. You may also want to test the temperature of your water when it reaches its destination to make sure that it is not too hot for plants.

Q What kind of plants like greywater?

A Citrus, fruit trees, blueberries, azaleas, camellias, most acid loving plants love greywater. Avocado and natives may be a bit sensitive. You can purchase aquarium strips to test your water. Anything above 7, iron will not available to plants.

Q What are some installation tips for beginners?

A Use a 3 way diverter valve, don’t skip this step! This way you can have the option of sending your water to the sewer if you have to use something toxic. Or if you have a really hard rain and the ground is already saturated, or you have relatives staying who might wash dirty diapers in your laundry (also a health hazard). Give yourself a way out. Label your greywater lines, HDPE comes with a purple stripe that indicates that it is greywater. You don’t want to confuse your potable and greywater lines. Also, I highly recommend HDPE pipe over PVC or ABS. PVC is toxic in every way and will leach toxins into your soil. To buy good quality fittings, Oasis Design is Art Ludwig’s website and there are fittings for sale as well as about 600 pages of greywater information, also try Dripworks USA.

See Laundry to Landscape pdf here...

Lynne Latham is also a graduate of the PermaCulture Design Certification course. For more information, contact Lynne at