Using Greywater from your Washing Machine

With our current bad drought conditions it makes no sense to pour perfectly good water down the sewer. So we just joined the greywater underground with our illegal washing machine surge tank, and the installation was a piece of cake.

We built our washing machine surge tank based on the design in Art Ludwig’s book Create an Oasis with Greywater. The purpose of the surge tank is to prevent the built-in pump in the washing machine from burning out, which might happen if you tried to pump the water through pipes. The tank also slows down the flow of water going out to the garden, allowing more time for it to percolate into the soil. In addition the tank lets the water cool a bit, should we run a load in hot water.

Bottom of barrel showing fittings

Top of the barrel where the hose from the washing machine comes in

For the tank we picked up a used and cleaned 55 gallon plastic drum with two “bung holes”, and plumbed it based on a design from The folks at Aquabarrel offer kits or a DIY video. We put our barrel together ourselves with a couple of common pvc fittings from the hardware store and omitted the overflow pipe, since our washing machine load will never exceed 55 gallons. The basic idea behind the Aquabarrel design is to turn the barrel upside down and use the preexisting threaded bung holes to connect up a garden hose. It took just a few minutes to complete, and our washing machine surge tank was ready to use. We highly recommend the Aquabarrel design, and you could combine a washing machine surge tank with a rain barrel with the addition of the overflow pipe and a fitting for the gutter.

When we do a load of laundry the waste water that collects in the barrel flows immediately out the garden hose and down towards the front slope of our little compound. Ludwig warns against keeping grewater around as it will quickly turn septic. We use Oasis Biocompatible detergent which is manufactured specifically for greywater systems. Regular “eco” detergents, while not harmful to aquatic plants, often contain substances that will kill terrestrial plants so you must use a greywater specific detergent.

Our next step will be to figure out some plantings that will take advantage of our laundry schedule, and to construct some simple earthworks and mulch basins to accommodate the water flow. Right now we just let the water percolate into the front slope, and our rosemary and Mexican sage look a lot healthier for it.

Our Rocket Stove

  • Editor’s note: we have a new design for a portable rocket stove here.

Low-tech is the new high-tech, and the best example of the low-tech revolution is the miraculous rocket stove–a stove that makes it possible to cook with small twigs–no logs needed! Best of all rocket stoves are easy to build. We liked the idea so much that we decided to build a permanent one just off our back deck for entertaining and as a backup to our gas stove should an emergency take out our utilities.

The rocket stove was developed for use in poor nations where wood used for cooking has led to the vast, wholesale, deforestation of large swaths of the earth’s surface. Rocket stoves can be built out of metal or masonry and consist of a L shaped tube, at the bottom of which you place your wood. The chimney effect creates a highly efficient, largely smoke-free burn. There’s no need to cut down a tree to cook your dinner–all you need is a few small branches or twigs.

Before we built the rocket stove we considered making a cob oven, a mud domed wood fired oven in which you can cook bread and pizza. There’s a trend in the eco-world to build cob ovens and we felt a certain pressure to keep up with the eco-Joneses. We started to build the base for one and then began to think about how often we would actually build a fire, especially considering that it has to burn for several hours before a cob oven gets hot enough to cook in. Also, where would we get the logs? And how good is it to burn such a fire and contribute to Los Angeles’ already smog choked air?

Staring at the bricks we had scavenged to build the base of cob oven, we realized that we could re-purpose them for a permanent backyard rocket stove that we would actually use. Furthermore we realized that our rocket stove could burn some of the palm fronds that regularly tumble down from the iconic palm trees that line our old L.A. street.

Here’s the materials we used:

36 bricks
4-inch galvanized steel stove pipe elbow
4-inch stove pipe
ash (scavenged from park BBQs)
1 tin can
50 pound bag of premixed concrete for the base
mortar mix
grill (scavenged)

The first step was to make a small foundation for the rocket stove. We fashioned a 18 by 18-inch by 4-inch slab with 2 x 4 lumber and a bag of premixed cement. Folks in cold places will need to make a deeper foundation to avoid frost heave.

Next we built a brick cube, leaving a small hole for the bottom of the stovepipe. For advice on how to build with brick we recommend taking a look at this. As you can see our masonry could use some more practice, but the results are not too bad–we like to think of our stove as being a bit “rustic”. You can avoid the hassle of brickwork by making a simpler rocket stove–check out these two instructional videos, one for a metal model, and another version using bricks. We chose brick largely for aesthetic reasons and we’re satisfied with the results.

Drawing from Capturing Heat

The next step is to put the pipe together fitting the elbow up into the longer pipe, and sized so that the top of the pipe is just below the bottom of the grill. Check out our earlier post for a video that can help with this part of the assembly. Serendipitously, on a bike ride, we found a grill in the middle of Sunset Boulevard that fit the opening in our brick rocket stove exactly.

You pour the ash into the completed brick cube to fill the space between the pipe and the inside wall. The ash acts as insulation to increase the efficiency of the stove. You could also use vermiculite but note that sand or soil will not work. Insulation works because of small pockets of air between particles, hence the need for ash or vermiculite, which are also non-combustible. We used a piece of scrap sheet metal with a 4-inch circular hole cut in it to keep the ash from spilling out the gap between the pipe and the squarish opening at the bottom.

Lastly you use a tin can sliced down the side and flattened out to form a shelf which you insert into the elbow at the bottom of the stove. Note the drawing above for the shape of the shelf. You put your twigs and kindling on this shelf and start the stove up with newspaper underneath the shelf. As the twigs burn you push them in over the edge to keep the fire going.

Our first test run of the stove was very successful–we boiled a pot of water and cooked some eggs in a a pan. The fire burned cleanly with little smoke except during start up. For more info on rocket stoves check out the Aprovecho Research Center.

And please people don’t burn wood inside and watch out for embers. Make sure you put the fire out completely when you are done cooking!


Homegrown Revolution neighbors Annelise and Eric intercepted us on our nightly dog walk and not only invited us up to their front porch for a glass of wine, but also sent us away with a couple of plantains harvested from their next door neighbor’s tree. It’s exactly what we’d like to see more of–folks growing food instead of lawns and everyone sharing the abundance.

While there’s a lot of banana trees in Los Angeles they tend not to yield edible fruit since our climate is not quite hot and humid enough. But plantains, judging from the delicious taste of the ones we fried up, are a different story. They do require a lot of water to grow, but greywater expert Art Ludwig calls bananas (the same family as plantain) “the premiere plant for greywater in warm climates”. You can bet that as soon as the building inspectors sign off and leave the scene of our newly retrofitted foundation at our crumbling 1920s vintage compound we’re going to try to figure out a way to route the shower drain out to a new mini-grove of plantain.

We’ll be our own banana republic and do the world a favor considering the amount of blood that has been spilled bringing bananas to North America. Witness Chiquita’s recent admission to teaming up with right wing terrorist groups in Columbia.

In the meantime, for the Homegrown Revolution readers out there in warm climates here’s the lowdown on growing bananas and plantain.

Rainwater Harvesting for Drylands

“The bricoleur, says Levi-Strauss, is someone who uses “the means at hand,” that is, the instruments he finds at his disposition around him, those which are already there, which had not been especially conceived with an eye to the operation for which they are to be used and to which one tries by trial and error to adapt them, not hesitating to change them whenever it appears necessary, or to try several of them at once, even if their form and their origin are heterogeneous.”

-Jacques Derrida

Homegrown Revolution loves cheap low-tech solutions (not to mention pretentious quotes), which is why we especially like “bricoleur” and Tucson rainwater harvesting guru Brad Lancaster and his ongoing book series Rainwater Harvesting for Drylands. Volume one is already out and volume two is due out this summer. Landcaster’s ingenious methods involve little more than careful observation and some work with a shovel. He suggests that harvesting rainwater begins with considering the flow of water from the highest point (which for most people will be the roof) to the lowest point in your yard and then simply figuring out simple ways to get that water to percolate into the ground to nourish your plants.

We’re especially fond of his method of hijacking street gutter runoff and directing it with a small improvised check dam into a dug out basin in the parkway. We’ve watched our neighbor’s lawn watering runoff for years and wondered if we could find a way to use that water. You can watch two videos showing Lancaster at work here. And a podcast here.

Flexible PVC Pipe for Greywater

Following up on an earlier post about using your washing machine’s greywater in your garden we thought we would revisit the sexy and exciting world of flexible 1″ pvc pipe and other exotic plumbing materials to be found in the isles of your local pool and spa supply shop–the unlikely go-to source for greywater revolutionaries. Flexible pvc pipe is probably the easiest way to run washing machine waste water out to your plants, just like you would with a garden hose. But garden hose could burn out your washing machine’s motor because it’s too small and has a tendency to kink up, hence the need for flexible 1″ pvc.

Another handy item from the bourgeois land of pools and spas is the swing check valve which will keep waste water from flowing back into the machine and gunking up your clean clothes. We hope graphic designers will appreciate (or perhaps not) those glowing blue drop shadows, but we digress. Apparently, this back-flow problem is not an issue with all washing machines so we’d hold off on getting one of these slightly expensive things until you know it’s an issue.

We’ve already discussed the not-safe-for work-sounding “three way diverter valve” which seems like something this business located in our neighborhood might carry (NSFW!). The tree way diverter valve, you may recall, is a way to send that greywater temporarily back to the sewer should the need arise. Another, much cheaper way to divert grewater is with a duo of two way valves. The radical Greywater Guerrillas of Oak-town show you how to do this on their fantastic website (which seems temporarily to be under construction–check back later).

So when the inevitable zombie hordes cause chaos across the land, just remember that you can scavenge hot tub parts in their wake to run your greywater system.

A Bicycle Powered Washing Machine

Homeless Dave’s Bike Powered Washing Machine

Of all the potential bicycle powered applications, other than the primary one of simply gettin’ around, washing machines seem the most practical to us. With the bike powered wash cycle, someday spin class and laundromats could co-locate. In the meantime, if you’ve got the space, a BPWM can also water your garden while giving you a chance to loose a few pounds.

There are a couple of designs floating around the internets, but we like Homeless Dave’s the best because it you don’t need to do any welding or fabrication of special parts. Homeless Dave’s extensive instructions require scavenging a bike, a trainer (we found one in the street, but we’ve also seen them at garage sales and thrift stores), and a top loading machine.

Homeless Dave’s design only does the spin cycle, not the washing, so it will be up to Homegrown Revolution to come up with a design for a full-on bike powered washing machine (we’ll wait for our hated Sears model to die first). When that day comes we’ll post the design and a special soak and spin music mix.

Rain Barrels

Constructing a cistern large enough to supply potable indoor water is an ambitious project involving pumps, filters, UV purifiers, and very large and expensive tanks. We don’t want to discourage anyone from making an attempt at it, but for most urban homesteaders it won’t be economical or practical given the space requirements and weight of thousands of gallons of stored water. Thankfully, there are simpler strategies for harvesting rainwater.

Rainwater used for irrigating plants does not need filtering or purification, and since outdoor watering accounts for the number one household water use, you’ll be using that water where it is most needed. Now, once again at the risk of sounding like a broken record, our strict rule around the SurviveLA homestead is that all irrigated plants must be useful, i.e. you gotta be able to eat it or make tea with it. Priority in our plantings goes to useful plants that don’t need additional water once established. But it’s still nice to have citrus trees, salad greens, rapini, beets, and other fruits and vegetables that do need supplemental irrigation. For these types of plants it’s possible to supplement municipal water with rainwater collected in barrels.

You can purchase commercial barrels made of this purpose, but it’s also possible to construct your own using surplus barrels with the same improvised bulkhead fitting we described in our post on washing machine greywater harvesting. In fact your rainwater collection barrel is pretty much the same as your washing machine greywater surge tank, but instead of being connected to the washing machine, it’s connected to your gutter downspouts. Depending on how much rain you get and how many loads of laundry you do, it may be possible to double up and use the same barrel. And, just like your greywater surge tank, it’s best to elevate the rain barrel to let gravity do the work of getting the water where you need it and thereby not have to deal with the cost and complexity of pumping water.

Some precautions–your rainwater barrel should have screens over the inlets to prevent mosquitos from breeding and it’s wise to rig an overflow pipe at the top of the barrel to channel water away from your homestead’s foundations. You will also need to clean the barrel periodically, and where it freezes it may be necessary to turn the barrel upside down for the winter.

Sizing your rain barrel system, or determining if using a rain barrel is worth the effort, requires going back to the formula we discussed earlier. But instead of figuring out how much water per year your roof can collect, you need to consider the amount per month. Monthly rain data for cities in the US can be found here. Rain barrel harvesting makes the most sense in places where it rains throughout the growing season, with the barrels providing additional water to bridge gaps between rains. In a place like Los Angeles where all of the rain is concentrated at one time of the year, rainwater barrels may not be practical.

To size up your rain barrel collection system it’s possible to daisy chain several barrels together using yet another bulkhead fitting towards the top of the barrel and pvc pipe to connect them together. There is also a commercially available kit for this purpose. Remember that bulkhead fittings are notorious for leaking, so be precise with your improvised plumbing work.

SurviveLA believes that all greywater and rainwater harvesting systems should be kept as simple as possible since most folks are lousy at doing any kind of maintenance (when was the last time you drained your water heater?). And, with the low cost of municipal water, even a simple system built with surplus parts probably won’t make sense from an economic standpoint. But, aside from being just generally groovy, rain barrel water collection could be an insurance policy for the uncertainties of global warming. Someday water may be more valuable than oil . . .

Rainfall Harvesting Math

Our next step in designing a rainwater harvesting system is to figure out how much water your rooftop will provide.

To do this measure the outside perimeter of your roof–you need not take into account the pitch or slant of the roof, since this does not affect the amount of water collected. Next, use the following formula:

collection area (square feet) x 0.6 x collection efficiency factor x rainfall (inches) = gallons per year

The collection efficiency factor is basically how good your roof is at shedding water. Metal roofs are the best and have the additional benefit of reflecting the heat of the sun and being less prone to leaks. Figure on a efficiency factor of .95 for a metal roof. Pitched asphalt shingle roofs are next with a efficiency factor of .9. Tar and gravel roofs are the least efficient with a factor of .8. Both tar and gravel and asphalt shingle roofs retain a fair amount of water after a rain, but they will still work fine for rainwater collection.

Data on both yearly and monthly average rainfall can be found on the National Oceanographic and Atmospheric Administration website.

For our house here in Los Angeles, we have a collection area of 992 square feet, a pitched asphalt shingle roof and an average of 15.06 inches of rain a year. So the average amount of rain we could collect in a year would be:

992 x 0.6 x 0.9 x 15.06 = 8,067.34 gallons.

If we lived in Atlanta, where the average annual precipitation is 48.6 inches per year we could theoretically collect 26,034 gallons of water a year.

With these numbers in mind we can begin to answer a few questions. Does rainwater collection make sense for your climate and living circumstances? If so, what kind of system will work?

In the Gutter

Our roofs, of course, are another impermeable surface that prevents rainwater from going where it should go–to our edible landscape. We can minimize the surface area by living in as small a house as possible and trying to maximize open ground. At our own compound we’ve even gone so far as to remove some previous resident’s bad addition and reduce the footprint of our house. So called green roofs, which have soil and plants growing on them our an option for the wealthy, but at present are still rare in the US. Most of us will still be dealing with conventional roofs.

Now assuming you’ve got a roof we will hope that you have gutters. Gutters have two purposes, to channel water away from your fragile and very expensive to repair foundation, and to channel it to where that water can be useful, to your edible landscaping. As much as we support self-sufficiency, putting on gutters is a job we think is best left to professionals, specifically professionals who produce seamless gutters with a machine like the one pictured above. Putting up gutters yourself can often be a frustrating experience that you must perform while balanced high atop a ladder. Gutters must have the correct slope or water will stagnate and create the perfect breeding ground for mosquitoes. If they leak you run the risk of rotting out your fascia boards. By all means, if you can afford it, hire a professional for this job. If you can’t afford it go sell some crack on the street corner until you have enough money. The do-it-yourself gutter systems available at home centers, especially the plastic kind, look like crap even in the off chance that you install them correctly.

While we’re big believers in sloth and idleness, one task that absolutely must be performed at least once a year is to get up on a ladder and clean out the gutters. Otherwise, you will be attempting this task, as we have on several occasions, during a downpour at midnight, after the downspouts have clogged up sending a cascade of water over the damned up gutters.

Two simple bits of technology can make gutter cleaning easier. We have inexpensive strainer baskets made out of 1/4 inch hardware cloth in each of the downspouts to keep them from clogging up. Some may wish to consider leaf guards which run along the top of the gutter to keep out leaves and other debris. The problem with leaf guards is that in order to clean out your gutters you must tediously remove the guards along the whole length of the gutter while, once again, balanced precariously on a ladder. While leaf guards catch large leaves, smaller stuff can still get through, so you might as well just stick with the strainer baskets in most situations.

Gutters are just the first step, however. Downspouts must be incorporated to carry that water from your gutters to where you can put that rainwater to use.

Water Conservation

“the price we paid was the price men have always paid for achieving a paradise in this life — we went soft, we lost our edge.”
-Frank Herbert Dune

SurviveLA was planning on discussing rainwater collection today, but we realized that we would be getting ahead of ourselves without first discussing what we call BOC, or boring old conservation. So before delving into greywater and rainwater harvesting it’s time to assess where your household is in terms of water consumption and see if that level can be reduced. It’s generally far easier and less expensive to conserve resources than it is to resort to the latest techno-eco-gadgetry.

So let’s count down the major sources of domestic water use (according to percentages calculated by the American Water Works Association Research Foundation) and consider how to conserve:

58.7% Outdoor Water
Clearly, the place to start with water conservation is outdoors, in designing a landscape that doesn’t need supplemental irrigation. Our rule around the SurviveLA compound is, once again, if you gotta water it you gotta be able to eat it. The vegetables that we grow are irrigated with a water-saving drip irrigation system that we’ll describe in detail in a later post. We have no lawn, and other than the vegetable garden, all the other plants are either natives or from the Mediterranean, many of which are also edible. Reusing greywater from your shower and washing machine can also reduce the amount of outdoor water usage. Above all remember that lawns are the wasteful and evil thought-spawn of generations of golf-obsessed Republicans. Replace them with edible landscaping, or decomposed granite.

10.8% Toilet
All toilets should be low-flush, and todays low-flush toilets are considerably better than the first generation. A low-flush toilet uses less than 1.6 gallons of water compared to 3.5 to 5 gallons for an old toilet, which many municipalities will give you a substantial rebate for getting rid of. If you live in an apartment or don’t have the energy to dump the old crapper, it’s possible to fill a plastic water bottle with stones and put it in the tank to displace and thereby reduce the amount of water used to flush. Don’t use a brick for this purpose since it can kick around and damage the flushing mechanism.

And remember the charming slogan, if it’s yellow let it mellow, if it’s brown flush it down. The mellow yellow strategy can save hundreds of gallons a year. This idea can be automated with a so-called dual flush toilet. These toilets, common in Europe, have two buttons–one for pee-pee and one for poop. Most dual flush toilets use the standard low-flush rate of 1.6 gallons when you hit the #2 button, but use only .8 gallons when you hit the #1 button.

And don’t use the toilet as a trash can. Not only does this waste water, but it puts an additional burden on sewage treatment plants. Having visited a sewage plant in person, SurviveLA can personally attest to the depressing sight of witnessing hundreds of plastic tampon applicators afloat in a vast sea of poo.

8.7% Clothes Washer
Wash only a full load. Run the waste water outside to irrigate your landscaping using either a surge tank, or directly.

Adventurous homesteaders, willing to put in the extra labor, may wish to consider a James Washer, an electricity free hand washer, commonly found in off-grid households, where you put some hot water in and agitate the clothes for a few minutes with a lever on the side. A hand wringer is used to dry the clothes before hanging them on a clothesline. A simple drain line can be hooked up to a hose and run out to the garden.

6.8% Shower
Shower less and celebrate your body odor–pretend you are the type of person Andy Warhol used to lovingly refer to as Eurotrash. Barring lifestyle changes, install a low-flow shower head. Also consider a shower head with a cutoff valve to allow stopping the water while soaping up. Use a bucket to catch the water that flows before it heats up. Use this water for plants or to “bucket flush” the toilet.

It’s cheating somewhat, but take your showers at the gym and let someone else pay for the water.

6.3% faucet
Turn off the water until needed when brushing teeth or shaving.

5.5% leaks
This is a no-brainer, but something everyone seems to forget. Fix leaks immediately! The knowledgeable folks at your local hardware store (not the idiots at Home Depot!) can tell you how.

.6% dishwasher
Run your energy efficient dishwasher only with full loads. And incidentally, a study conducted by the University of Bonn in Germany concluded that dishwashers use half the energy, one sixth the water, and less soap than hand washing.

One last sobering statistic to remember–the average American uses between 80 and 100 gallons per person per day, with the higher consumption coming from folks living in the dry Southwest. The average African uses 5 gallons a day.