Laundry to Landscape Grey Water System
Complete information from the original inventors
by Art Ludwig
Design updates, parts sources and installers for the Laundry to Landscape Greywater System—the simplest, most economical greywater system to install yourself as an owner or renter.
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We originated the Laundry to Landscape Greywater System and published it unpatented into the public domain in 2008 for the good of all.
This site has the most up-to-date, reliable, and complete information, and is the source of much of the info replicated on tens of thousands of other pages on "Laundry to Landscape." Please help the quality of information on this system and support our continued research by "liking" and linking to us, getting our instructional DVD or book, and encouraging organizations that have not done so to credit us as a source of original information on this topic--thanks!
Greywater Book and Video Set: Create an Oasis with Greywater, Builder's Greywater Guide, Principles of Ecological Design, Laundry to Landscape instructional DVD $51.80 ($13 savings)-
Laundry to Landscape Instructional Video Produced by Art Ludwig, published by Oasis Design, 2010. 90 minutes
DVD—$19.95 Soy ink color printed in a recycled cardboard case. ISBN 0-9643433-8-X. Digital Download—$14.95 Choice of resolutions.
<click for bigger image with labels>
The Laundry to Landscape system is the simplest, least expensive, lowest effort way to get the most greywater out on to the home landscape most effectively.
Due to its inherent simplicity and low cost, it has been widely adopted, accommodated in building codes, the subject of numerous government rebates, workshops and government training. It is the graywater system which is most suited for professional installation by landscapers. In many parts of the world it is likely that someone could make their own small business based entirely on the installation of these systems.
This page is intended to be an index to (1) current best management practices for building your own Laundry to Landscape System, as well (2) as the information to run a business installing them. In other words, an "open source franchise" for landscapers, plumbers, and contractors to share tips about how to best design, install and maintain these.
If you have design tips or photos to share, please Email us (if you want to send an attachment please fill out our web based contact form to get our regular e mail address. You can then send attachments to our regular e mail address.)
At the bottom of the page are referrals to local installers who can build one for you. Greywater Action is the premier provider of workshops on Laundry to Landscape (and other) greywater systems.
The information in the next section is excerpted from the April 2009 printing of Oasis greywater-book.
Here's the way it looks in print: Laundry to Landscape (PDF 1mb).
Video Excerpt
Watch an excerpt from our instructional Laundry 2 landscape-video:
Laundry to Landscape Instructional Video Produced by Art Ludwig, published by Oasis Design, 2010. 90 minutes
DVD—$19.95 Soy ink color printed in a recycled cardboard case. ISBN 0-9643433-8-X.
Digital Download—$14.95 Choice of resolutions.
Laundry to Landscape System Design (Excerpt fromOasis greywater-book)
An Oasis Design refinement of an old idea. Most homes in arid areas or on septic tanks should have one. It is a cost-effective retrofit system, and renter-friendly. It can irrigate areas level with or slightly uphill from the washer. This is the system I recommend most often, usually in combination with a Branched Drain or Green Septic system.
People commonly attach garden hoses to their washers. There are several issues with this practice (listed on p. 106), which the Laundry to Landscape system addresses (Figure 7.6).
It uses 1" polyethylene (the most “eco” plastic) to accommodate the rush of water from the washer, without a surge tank or stressing the pump. Thus, the washer itself pumps water a large distance horizontally, or a short distance vertically, to multiple outlets (six to 18 of ‘em), without moving a hose.
The diversion occurs upstream of the standpipe (the drain the washer outlet hooks into). You don’t have to mess with the house drain plumbing. (This is a point we’re stressing in our campaign to have California allow their installation without a permit or an inspection.)
The current state of the art design follows...
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^ | Introduction | Design | Parts | Parts Sources | Maintenance | Installers | Laundry 2 landscape-video (GW book and DVD video set) (L2L video download) (L2L video DVD)
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^ | Introduction | Design | Parts | Parts Sources | Maintenance | Installers | Laundry 2 landscape-video (GW book and DVD video set) (L2L video download) (L2L video DVD)
Washer Pump Performance and Distribution Plumbing Limitations
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| Leveling a Laundry to Landscape line buried 4" deep in a hard-freeze climate. This line ran fine all winter, even though the plumbing inside the house froze! |
Laundry to Landscape systems use the washing machine pump (A, in figure 7.6) to distribute the water. Without stressing the pump you can irrigate any distance downhill, or pump up to an elevation 2’ below the top of the washer 100’ away (100’ of horizontal 1” tubing offers the same resistance as 20” of vertical rise). The resistance the pump has to overcome should ideally be about the same as in a standard installation, where the hose discharges at the height of the top of the machine. For example, if a washing machine empties through 100’ of 1” pipe that ends 18” lower than its lid, the effective resistance is the same as if it
discharged 2” above its lid. At considerable risk to the pump, I've seen people irrigate up to 6’ above the top of the washer.m The variables that affect pump life are:
• Pump model—Higher-quality pumps perform better. Unfortunately, every washer pump is different. The way to determine if the pump is adequate is to try it and see if it burns up (which is rare).
• Height differential—The less rise, the easier on the pump. I wouldn't go more than 6’ up.
• Pipe flow resistance—The pipe should not be less than 1” diameter, and should not kink.
Diversion
The laundry diverter valve (B) is usually mounted on the wall behind the washer, or where it is easily visible and convenient to turn. It should be solidly screwed to the wall using copper pipe brackets or plumber’s tape, so that it does not wiggle when the handle is torqued. One side of the valve diverts water into the standpipe through an air gap, the other through the wall or window to the outside. The greywater destinations should be clearly labeled, e.g., “ocean” and “citrus trees.”
Vacuum Breaker
If the first outlet is lower than the level of water in the washer, a vacuum breaker (C) is advised to keep the drain line from continuously siphoning water out of the machine as it tries to refill itself (not a problem with every machine or load, but ...easier to just add it). The loose fit of the washing machine drain hose into the standpipe in conventional plumbing creates an air gap, which serves as a vacuum breaker. The vacuum breaker must connect to the main line at its high point to be effective. This is typically close to the washer, just outside the house. If the line must dip down before leaving the house, it could siphon even with a vacuum breaker outside. In this case, mount the vacuum breaker inside. To avoid the possibility of spillage indoors, you can route a ½” tube from the top of the vacuum breaker outlet back into the septic/sewer drain standpipe (spills are rare from an auto vent).
If you’re irrigating uphill and the first outlet is above the top of the washer, it will serve as
the vacuum breaker.
(In some installations it can be skipped if A) the first outlet is
above the level of the water in the washer, or B) the washer is plumbed
internally in such a way that vacuum from the outlet hose is broken (some are).
This can be checked by lowering the outlet hose when the washer is full and
seeing if water runs out when it is not supposed to. and into the greywater system with some washers, if the
first outlet is below the level of the top of the water in the washing machine.
Note that if the washer or the greywater distribution plumbing changes in the future, it may be
necessary to add the vacuum breaker later anyway.)
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^ | Introduction | Design | Parts | Parts Sources | Maintenance | Installers | Laundry 2 landscape-video (GW book and DVD video set) (L2L video download) (L2L video DVD)
Automatic Bypass (freezing climate only)
If the line could freeze, you must have an automatic bypass. This is a pipe through which the water rises and harmlessly overflows when the line clogs with ice instead of burning out the pump or flooding the house. The ideal bypass makes an audible splash so you know what’s up. The tall vent vacuum breaker option shown as a ½” line at the right of Figure 7.6 could double as an automatic bypass if it were made of 1” tubing. You’d certainly notice when greywater fountained all over the side of your house. Perhaps one of you from a freezing climate will come up with a better design with less drastic notification of frozen lines. If the distribution lines slope downhill continuously they probably won’t freeze (photo).
Hose Service Connection
A hose service connection (D) makes tuning the outlets easier (you won’t have to keep doing load after load of laundry to check and tune outlet flows). It is also good for blowing out lint, if needed (or blowing the system apart if you pressurize it more than the 20 psi (140 kpa) that this type of plumbing is designed for). The hose service connection must be properly installed so there is no chance of greywater backflowing into the freshwater lines. The layers of protection against this are: 1) to connect the hose, the washer must be disconnected; 2) the swing check valve (below); 3) a backflow prevention device at the hose bib.
 greywaterguerillas.com |
| Zone valves in valve box made from a recycled plastic drum. |
Outlet Options |
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| Hole drilled in tubing as emitter. Seems like cheating, it’s so easy, but they’re working great so far. Put them on the bottom of the line so greywater isn't geysering everywhere. A 7/32” (5.5 mm) hole is the right size to be able to plug them with drip “goof plugs” if you change your mind about the location. |
greywaterguerillas.com |
| 1" x ½" tee outlet. |
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| ½” ball valve outlet tee (have to shorten barb). |
To tune the outlets perfectly, check the flow from the washer by timing how long it takes to fill a bucket. Then adjust the hose to the same flow.
Backflow Prevention Valve
If the drain line runs (or can be lifted) above the height of the top of the washer, a swing check valve (E) should be included as close as possible to the washer, to keep water in the line from rushing back into the machine when it shuts off. Get a clear one with 1” pipe thread—a clean installation and you can watch what is happening inside.
If you have a hose service connection, a swing check valve adds backflow protection.
Distribution Plumbing
To get the pressurized greywater to plants, 1” polyethylene tubing is the preferred distribution plumbing (F), ideally the kind with a purple stripe to indicate non-potable water. Smaller tubing gives too much resistance. Bigger tubing traps more septic water and crud and is a waste of plastic. PVC pipe destroys the environment, and is ugly.
You can run a single or multi-trunk line, with or without valves or branches. Branches can be 1”, ¾”, or ½”. With lots of greywater and/or low perk soil, use two or more valved zones (photo). All the plumbing can be under 9” of mulch for a California Plumbing Code appendix G legal system (Figure 7.6), otherwise it can just go on top of the mulch.
It is best for freezing, smells, and the pump if the line slopes downhill continuously. Second best: a U-shaped line with an outlet at the low point to drain the U.
However, because the line is pressurized, it can dip up and down. The consequence is some trapped water in the line between uses. Unless the line might freeze, this is acceptable. The water can go septic if it sits for more than a few days. However, the quantity in even a long run of 1” pipe is so small that any objectionable smell is only detectable for the first moment of discharge. In an installation that includes both some rise and a long horizontal run, the quantity of trapped water is minimized by sending the pipe up to the maximum height as quickly as possible, then running the pipe down from there. This way, most of the run drains dry after each use. This same geometry works to get the water up from a basement washer to the yard in a freezing climate, as this places the part of the line that holds standing water inside the thermal envelope of the house (you could also add a surge tank and effluent pump).
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^ | Introduction | Design | Parts | Parts Sources | Maintenance | Installers | Laundry 2 landscape-video (GW book and DVD video set) (L2L video download) (L2L video DVD)
Outlets
The capacity of all the outlets (G) should be enough that the pump is not strained trying to push too much water through too small or too few holes. On the other hand, too many or too large holes will result in pressure loss that may leave some outlets high and dry. The total cross-sectional area of all the outlets in a zone should be 1–2 in2 (the Laundry to Landscape Calculator can be used to find the total cross-sectional area from a variety of outlets).
Note that outlet flow in this pressurized system, unlike a gravity flow system, depends on the height, the size, and the number of outlets, as well as the length and diameter of the tubing. You can tune the flow by making the outlets different sizes, or adjusting the outlet ball valves (photo below). If you are irrigating uphill, the first outlet will get way more water than the last outlet. To avoid this, run a solid line to the high point, then do a U-turn and put all the outlets in the downhill run.
Measure the flow from the washer as it’s peaking by collecting it in a 5 gallon bucket.
Turn on a hose so the flow is the same.
Hook the hose to the system hose tee.
Disconnect the hose and try running a load of laundry and catch the water from each outlet in buckets to see if it is as it should be.
Diameter
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Cross-sectional area
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Thing
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|
|
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Number to equal 1"
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1.04
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0.85
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1.00
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1" poly line
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0.47
|
0.18
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4.88
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1/2" drip ball valve barb
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0.30
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0.07
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12.48
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3/8" drip barb
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0.57
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0.26
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3.34
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1/2" poly line
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0.83
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0.54
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1.59
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3/4" poly line
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Receiving Landscape
Mulch basins (H) are the way to go. With the dimensions indicated in the drawing, they can be legal under the CPC. Otherwise, the hose can go on the surface and the outlets can be directed straight down into the mulch.
Not every installation requires a vacuum breaker, check valve, hose service connection. But, if you include the applicable components, the chance of having trouble with your system is much smaller, and including all of them won’t hurt.
Updates
greywaterguerillas.com |
| Outlet shield in mulch basin (5 gal pot). |
Evolution of Laundry to Landscape best practices since the last revision of the instructional DVD:
Plastic pots as outlet shields not durable enough—these have been collapsing too easily, so the new best practice is something stronger; recycled buckets, sections sawn from plastic culvert, irrigation valve boxes, etc.
Test peak flow, use fewer outlets for high efficiency washers—the peak flow from high efficiency washers can be as low as 1.5 gpm, about a quarter that of vertical axis washers. This low of a flow is far more challenging to split, so you may need as few as 3 outlets per zone, and rely more on switching between zones to get even distribution of water.
In extreme cases...a movable single outlet may be most appropriate; that is, basically a laundry to garden hose system, built with L2L features (vacuum breaker, kink-guard overflow...). For example, one installation we encountered was for a single person with a 9 gallon per load machine; low peak flow and very low total volume; simpler and cheaper to put the 9 gallons on a tree and move the hose to another tree next week than to try and split the flow.
Smaller tubing for high efficiency washers—there is an optimum tubing size for a given flow and volume of water. An installation that is exclusively for high efficiency washers could potentially work better with 3/4" tubing instead of 1" tubing. The volume of water needed to fill the system is half as much, so outlets will be pressurized sooner, and less water will stagnate in the line. This is still experimental.
Take inertia into account—if there is standing water in the line, it takes force to get it moving. The equal/ opposite reaction to this is more pressure that the pump has to exert for the few seconds it takes to get the water moving. This is another reason to minimize standing water in the lines.
Design calculators
Laundry to Landscape Design Calculator (excel spreadsheet)
Make sure you have enough outlet capacity, and not too much.
Pipe flow resistance calculator
Parts
Download this Parts List (excel spreadsheet, working draft) for the laundry greywater system.
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^ | Introduction | Design | Parts | Parts Sources | Maintenance | Installers | Laundry 2 landscape-video (GW book and DVD video set) (L2L video download) (L2L video DVD)
Parts Sources
We sell the hard to find Laundry diverter valve. Most of the other parts can be purchased from Drip works. They selling the tubing, but its rolled overly tight and is all kinked. The tubing is best purchased locally, where it is generally found in 500 foot rolls.
Maintenance
The
maintenance consists largely of connecting to the hose tee and blasting the lint
out, opening and shutting ball valves as needed to accomplish this.
Installers
- Sweetwater collaborative Santa Barbara, California
- Dreamscape Santa Barbara, California
- Wilson Environmental Landscape Design Santa Barbara, California
- Catching H2O/H2OME, San Diego, California
- Greywater Action Oakland, California
- Greywater Action has a much longer list of installers who have completed their workshops
Submit your comments
Please Email us to share your experiences, questions or comments about the Laundry to Landscape Greywater System.
Further reading and watching from the bookstore
Greywater Book and Video Set: Create an Oasis with Greywater, Builder's Greywater Guide, Principles of Ecological Design, Laundry to Landscape instructional DVD $51.80 ($13 savings)
Laundry to Landscape Instructional Video Produced by Art Ludwig, published by Oasis Design, 2010. 90 minutes
DVD—$19.95 Soy ink color printed in a recycled cardboard case. ISBN 0-9643433-8-X.
Digital Download—$14.95 Choice of resolutions.
Acknowledgments
The following entities contributed substantially to the development of the Laundry to Landscape greywater system:
- Greywater Action Laura Allen, Andrea Lara and Christina Bertea-- activism for code improvements, images, first workshops, research, outreach, design refinements
- Wilson Environmental Landscape Design--design, installation and maintenance refinements; first adopters for professional installation
- Santa Barbara City Water Conservation Department Funded development of pubic educational materials, code compliance package; supported code improvements, first government agency adopters
- (if we missed you please Email us !)
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