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.

Click for larger image.Can 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 green!

Our complete set of plans includes a comprehensive tools 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 details.)

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).

Our Savings 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 more.

So what are you waiting for???



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