1. Aside from the obvious (chemical cleaners, non-biodegradable soaps,
bleach, etc.) there are two main substances to avoid: salt (sodium)
and boron (borax). Although non-toxic, salt build up will destroy the
soil over time. Boron is also non-toxic to people but a plant Greywater is water from your sinks, showers and washing
microtoxin, so don't use it! For the washer, these products are salt machines. It is NOT water from toilets or anything that has come
and boron free: into contact with feces. Greywater is safe and easy to reuse in
•Oasis •ECOS •Bio Pac Liquid Detergent. your own yard, saving water and money. To build any type of
Shower products are so diluted, the contents are unlikely to harm system you need to follow these basic guidelines.
your plants. Yet most shampoos and conditioners contain
reproductive toxins as well as carcinogenic material, absorbed into
your skin in the shower. To find healthy products go to
cosmeticdatabase.org and enter your products to discover their
toxicity. For questionable products divert the greywater back to the
sewer with the 3-way valve.
A lways distribute greywater to mulched basins (filled with wood chips or
straw). The size of the mulch basin depends on the plant size and the
amount of water discharged into it.
Before you install a greywater system there are many cheap
and easy ways to conserve water. Most water districts have
great water saving tips on their website and rebates. Low flow
fixtures,installing easy shut off switches on showers, choosing
GREYWATER LEGALITY : Greywater is technically legal in CA, but in
practice hardly anyone gets a permit due to the over
restricitveness of the code. Other states like Arizona, New Mexico, and
drought tolerant plants and mulching the yard are a few ways to
dramatically reduce water use.
Texas, have helpful and reasonable greywater codes, making it easy to
install legal systems for low cost. CA's greywater code is being
rewritten currently, see graywater.org or greywateralliance.org for
updates.

2. FROM THE SHOWER: Showers are a great source of greywater-
they usually produce a lot of relatively clean water. To have a simple,
effective shower system you will want a gravity based system (no
pump). If your yard is located uphill from the house, then you'll need
to have a pumped system.
Branched Drain: A branched drain system is the most robust
and effective of the gravity based systems for meeting irrigation
needs . The shower water travels by gravity (2% downward slope)
and the water is split in half multiple times using flow splitters until
the desired amount of water comes out each outlet. Branched drain
systems are best for trees and other large perennials, they are
impractical for lawns and small plants.
FROM THE SINKS: Kichen sinks produce a fair amount of
water, usually very high in organic matter (food, grease, etc.).
This water will clog many kinds of systems- we recommend
branched drains to large mulch basins to avoid clogging. Bathroom
sinks produce a smaller amount of water. If combined with the
shower water they will fall under the shower system, if alone they
can be drained to a single large plant, or have the flow split and
water two or three plants.
"DRUMLESS" LAUNDRY: This is a pressurized system-
the hose leaving the washing machine is attached
CONSTRUCTED WETLANDS: If you produce more water than
you need for irrigation, a constructed wetland can be
incorporated into your system to "ecologically dispose" of some of the
to 1" irrigation line with outlets sending water to greywater. Wetlands remove nutrients and filter particles from
specific plants. This system is low cost, easy to greywater, enabling it to be stored, or sent through a properly designed
drip irrigation system (a sand filter and pump will also be needed- this
install, and gives huge flexibilty for irrigation. In cost lots more $$). Greywater is also a good source of irrigation for
most situations this is the number one place to beautiful, water loving wetland plants. If you live near a creek, a wetland
start when choosing a greywater system! can protect the creek from nutrient pollution from GW. If you live in an
arid climate, or are trying to reduce your fresh water use, we don't
recommend incorporating wetlands into greywater systems as they use
FROM THE WASHER: Washing machines are typically the easiest
source for greywater. Each machine has an internal pump that
up a lot of the water which could otherwise be used for irrigation.
PUMPED
automatically pumps out the water- you can use that to your advantage SYSTEMS: If you can't use gravity to transport the
to pump the greywater slightly uphill (not too much!) or across flat yards. greywater (your yard is sloped uphill, or it's flat and the plants are far
away) you will need a "DRUM WITH EFFLUENT PUMP" system. The
LAUNDRY DRUM: The wash water is pumped into a "drum", a large
barrel or temporary storage (called a surge tank). At the bottom of
the drum the water drains out into a hose that is moved around the yard
water flows into a large (50 gallon) plastic drum that is either buried or
located at ground level. In the drum a pump pushes the water out
through irrigation lines (no emitters) to the landscape. Pumps add cost,
to irrigate. This is the cheapest and easiest system to install, but requires use electricty, and will break, so avoid this if you can.
constant moving of the hose for it to be effective at irrigating.
D etails of these systems are found in "Create an Oasis with
Greywater" by Art Ludwig.