Greywater Recycling

Greywater recycling is characterized as the reuse of household water from dishwashing, laundry, sink and shower usage, as well as the catchment and use of rainwater.

Greywater accounts for 50-80% of residential water waste and although it's generally clean of dangerous pollutants, it goes straight down the drain after a single use. And much of what is wasted has not actually been used at all, such as warm-up water from your shower or sink.

Greywater systems are what we put into place to catch and reusue this water. They can be simple and manual, or more complicated, automatic and gravity-fed.

Greywater vs. Blackwater

Before I go further, it is important to note there is a substantial difference between "greywater" and "blackwater". Blackwater is water that contains contaminants such as feces or harmful toxins (usually this is toilet water or any water containing harsh chemicals). Blackwater must undergo purification and should never be reused untreated.

Greywater recycling takes a bit more planning than other water conservation tips and it can be more work depending on your greywater systems.

One of the best uses of greywater recycling is in the yard or garden. Some greywater shouldn't be used on fruits or veggies, especially edibles in which the leaf is eaten (leafy greens, herbs, etc). Other times greywater may be used to clean outdoor items, or even wash the dog. Sustainably committed individuals can use greywater to flush their toilet, instead of the fresh water that is usually pumped into the holding tank.

But the use of greywater all depends on what the water has been used for and what is in it, so keep those soaps and cleaners non-toxic and biodegradable and steer clear of chemicals or other unhealthy substances. (You were doing that anyway, right?)

Start Greywater Recycling Today

Greywater recycling and greywater systems don't need to be complex. There are many simple ways to capture and use your greywater or water waste without a complicated system. These take a bit more time or work but using these tips can literally cut your water bill in half.

• If you have a garden, a large greywater tank or an array of upcycled barrels setup outdoors may be optimal in saving greywater for use at a more convenient time.

Statistics

Approximately 65% of household water use can be reused a second time as greywater.

• Put a tub or bucket in the shower or sink to capture warm-up water. This is clean water, and technically not greywater, so use this where ever you wish! Although they make new fancy water catchments for this, an old 5 gallon bucket that would have been thrown away works just as well. Do some searching on Freecycle to save money and resources. (And try to find one with a lid to minimize sloshing!)
• When washing fruits or veggies, fill a bowl with water to rinse. This water can then be reused in the garden, for houseplants or to flush the toilet.
• If you handwash your dishes, consider washing and/or rinsing in large bowls of water, rather than the sink. A bowl of icky wash water goes great in the compost. A bowl of rinse water can go almost anywhere. Be sure your soaps are all-natural.
• If you use a dishwasher, scrape excess food into the compost or trash, rinse any dishes in a small bowl of water, dump the water in the yard, garden or compost pile (depending on how dirty the water is)and then throw the bowl in the dishwasher with the rest. You can also reroute your drainage hose to go outdoors or into a tub in your home.
• When washing your hands or brushing your teeth, do so over a bowl to capture the greywater. This should be clean enough for use anywhere outdoors.
• Connect your washing machine drain hose to a bin or tub to drain the greywater. Be sure the bin is large enough to accommodate the wash and rinse cycles.
• An outdoor sink (or even an indoor sink depending on your level of commitment) can be retrofitted for collection under the sink by removing the plumbing underneath and replacing it with a water catchment device, such as a large bucket or basin. You would need to be more aware of your water levels to avoid overflowing.
• Depending on your yard design, the use of a pond or series of ponds or the use of slopes, channels and swales can help you disperse water throughout your garden.

Greywater Recycling Systems

Greywater systems are more complex than simply capturing waste water in a bowl. It works as indoor plumbing should, and without much help from us other than maintenance.

Normally gravity-fed, greywater systems may direct your greywater from your indoor plumbing into holding tanks outdoors (similar to rainwater catchment). Holding tanks should not need any treatment but should be covered to prevent a mosquito breeding ground.

Greywater may also be fed directly into an outdoor pond or series of ponds. Ponds, given the right combination of plant and animal life, can even filter the water for you. Planting a landscape around the pond can ensure your plants get the water they need without any work from you.

Reader Questions

I don't know anything about plumbing, but I was wondering if you could offer me some advice on how I could utilize the pond water as a "back up" if the house does not receive enough rain water for bathing, cooking, etc...I guess I would need some type of pump since the house is higher up than the pond? What kind of pump is most sustainable? Another aspect of that is how to deal with the grey and black water. I have heard that it can be filtered through sand, and that the worms on the top will consume organic debris. Does that sound right?

Hi hun, great question. This isn't an area I'm very familiar with yet but I did some asking around. Obviously a gravity-fed pump would be ideal but in this case I think you are looking for a quality electric pump (tractor supply stores usually have 12v pumps - an electric pump that is connected to the power source for the home, whatever that might be, solar, wind, etc.) to run with solar (even a small array of its own). We once interned on an organic farm with this setup and I believe the battery bank was small, limiting nighttime usage. Feeding it into the homes electricity may help there.

When it comes to grey and black water I'd recommend researching "humanure". The Humanure Handbook is probably the best place. It takes about 2 years to properly break down the waste but it creates an effective "closed loop" system with the compost created at the end of the process. A closed loop system is one where nothing is wasted within the home's design, one thing supports another supports another, supports another. For instance many "Earthships" have this design, rain falls on a water catchment, which gets filter and sent to the kitchen sink, which goes down a drain that leads to planters within the home, the excess of which goes into the toilet system, all of which goes into a humanure system, which eventually goes back into the earth, the moisture of which eventually evaporating and coming down again as rainfall. (Grey is much simpler, it can generally be fed into trees, shrubs, etc...anywhere where it is not touching the food stuffs directly.) There is a book linked on our site for greywater systems below.

Books on Greywater Recycling and Greywater Systems

The scope of building greywater systems is more complex than a single article can describe. Here are some recommended greywater books for you to research further:

	The New Create an Oasis with Greywater: Choosing, Building and Using Greywater Systems - Includes Branched Drains by Art Ludwig		Builder's Greywater Guide: Installation of Greywater Systems in New Construction and Remodeling: A Supplement to the Book by Art Ludwig
	Graywater: The Next Wave by Curtis McLamb		Water Storage: Tanks, Cisterns, Aquifers, and Ponds for Domestic Supply, Fire and Emergency Use--Includes How to Make Ferrocement Water Tanks by Art Ludwig
	Gaia's Garden, Second Edition: A Guide To Home-Scale Permaculture by Toby Hemenway		Rainwater Harvesting for Drylands: Guiding Principles to Welcome Rain into Your Life And Landscape by Brad Lancaster
	Greywater reuse for the irrigation of food crops: an investigation of plant effects and microbial risk by Sara Finley		Rainwater Collection for the Mechanically Challenged by Suzy Banks
	Design for Water: Rainwater Harvesting, Stormwater Catchment, and Alternate Water Reuse by Heather Kinkade-Levario		Rainwater Catchment Systems for Domestic Supply: Design, Construction and Implementation by Erik Nissen-Petersen and John Gould

Ready To Take More Sustainable Baby Steps?

This article on greywater recycling is a little bit Baby Steps and a little bit Big Strides and a little bit Giant Leaps. Don't feel overwhelmed if you feel you've jumped ahead farther than you wish to go.

Just keep stepping through the information:

Whatever step you take, remember to have fun!