How does this system work?
Our Greywater Recycling System is
similar in principle to some of the commercially available
systems. It consists of a filtration chamber, separation/storage
tank, and pump with additional built-in safeguards against overflow and
underflow scenarios, venting, and a quick and easy bypass scheme to
allow the system to be taken out of the loop for maintenance.
As shown in the schematic diagram
below, this system is connected between your home's showers, bathtubs,
and washing machine and the public sewer system. It intercepts the
lightly polluted greywater and filters it on its way to the
separation/storage tank. Here, through settling and flotation,
impurities are further separated from the water. The water can
optionally receive chemical sterilization here, as well. An electric
pump then supplies the filtered greywater at the required pressure and
flow-rate to the toilets throughout your home.
I really build it myself?
Yes! With a free
weekend, a few tools, basic handyman and plumbing skills, and our
plans, you should be able to construct your own Greywater
Recycling System for about $350. All parts are off-the-shelf and should
be readily available at most home improvement or hardware stores.
Some components can be found "used" and may be available at
little or no cost to you. This would make your system even more
complete set of plans includes a
list, detailed fabrication diagrams, actual photos, assembly
instructions, and a materials list with parts sourcing
suggestions. Also included are suggested maintenance procedures,
tips and formulas for measuring the efficiency of your system and for
getting the most savings possible, a basic troubleshooting guide, and
ideas for additional features to help customize your system.
How much will it save me?
This is a difficult question
to answer, as savings will vary depending on the size and layout of your
home, the number of people in your household, your individual lifestyle,
personal schedules, utilities costs in your part of the country, the
size of your Greywater Recycling System, and other factors such as
optional solar power, etc.
In the U.S., about 30% of the average
household's water consumption goes towards flushing the toilet.
This may be higher if you have older toilets or if members of your
family are at home all day long. For instance, older
"standard" toilets use about 5 gallons of water per flush,
whereas newer efficient models will use less than 2 gallons per
flush. Also, on average, a household's toilets are flushed four
times per day per person. But you can see that if you work from
home or if your children are home-schooled, for example, this number
could be much higher.
We have personally seen an average of
about a 35%
reduction on monthly water bills where our system has been installed. Keep in mind that there are minimal operating costs --
filters, chemicals (if necessary), and electricity. These
costs can be as little as about $15 annually. If you run your pump on solar
power, for example, or you don't need to use chemical treatment, then
your costs could be even lower still. But even at $15/yr. with a
35% water savings, an average system will pay for itself in only 5 to 6 years.
(See our Savings Calculator for more
What about its "carbon footprint"?
Good question. This is another
type of savings you need to consider -- CO2 emissions.
Right now, using one gallon of tap water -- from collection,
purification, and pumping to the home, to pumping the sewage, treating
it, and pumping it back into the environment -- creates an average 1.55
grams of carbon dioxide
emissions. So for every 1000 gallons of water you save, you reduce
carbon emissions by 1.55 kilograms -- almost 3.5 pounds!
Realistically, this system can save at least four times that, or more, in
just one year... per household!
But this reduction does come at a carbon price -- the power required to
run the pump. The generation of one kilowatt-hour (kWh) of
electricity creates 450 grams of carbon dioxide. So you will use
the following equation to determine your net reduction in carbon
emissions (in grams):
[(gallons of water saved) * 1.55] -
[(kWh of electricity used) * 450]
Of course, if you are using solar
electric power, then your
annual carbon footprint reduction (in grams) will be even greater.
Simply use the left half of
the equation to calculate your carbon reduction -- 1.55 times your annual water savings (in gallons).
Calculator uses detailed
formulas to allow you to accurately calculate
the efficiency and savings of your particular installation, and our
plans contain numerous tips and tricks that will help to save you even
So what are you waiting for???
WANT THE PLANS! >>>