Laundry and the Low-water Landscape: Greywater Harvesting and Reuse, Part II

By Jessica

Once I saw how easy it was to use greywater, I wanted to try it in other situations. I had already started tossing the rinse water from the dishes onto one of my backyard trees to see if it would survive. It thrived! By the end of the summer I had switched my soap to a “garden safe” brand, and dishwater was the primary source of irrigation for three trees and a shrub. Nearly the entire front yard was by this time planted with drought- tolerant plants, which are usually greywater-tolerant as well. (The exceptions were a few blueberry bushes under the front windows. Blueberries are sensitive to the higher pH of soap residues in greywater.) Why pay money for drinkable water if the plants would be just as happy with the secondhand stuff? I just needed more of it.

Because most of our house is on a slab foundation, I couldn’t re-plumb the drain lines to catch all the greywater the way some really green homes are plumbed. My hubby never would have approved that notion, even if it were practicable. Freshwater only costs about $2 – $3 per hundred cubic feet in our area, or around 25-40 cents for every hundred gallons. Harvesting greywater is ecologically virtuous, but (at present rates) it doesn’t save enough money to be worth spending more than about $10 on any one project. Sometimes even the free ones weren’t worth the potential consequences. For example, I tried scooping water out of the tub with buckets after bathing the kids, then carrying the buckets out to the yard. But that got the floor dirty and slick. Pennies saved on water wouldn’t make up for dollars spent on a broken limb. I had to be more creative than that, and more thrifty.

I took to searching YouTube for inspiration, for videos of people collecting and using greywater around their homes. Many of them utilized the rinse water from their clothes washing machines. Top-loading washers can use as much as 40 gallons of water per load (front-loaders use about half as much), so they are a good source of large volumes of reusable water. This is particularly true if you use a “garden safe” brand of detergent, although my early experiments with dishwater indicated to me that many plants did fine with the regular stuff. It just depended on the plant’s tolerance for the various salts and other chemicals that are in the detergent. My plants were nearly all adapted to saline soil conditions. Saline soils are common in deserts and climates with long dry seasons, so desert and drought-tolerant plants are virtually always greywater-tolerant plants as well. I was fairly confident I could use not just the rinse water, but the wash water as well, so long as I switched to the low-salt garden-safe variety. If I could just figure out a way to do it that did not involve hauling sloshing, 40-pound buckets of water out to the front yard on washing days. Surely I could be that clever.

Daily scanning of Craigslist eventually netted me some used plastic 55 gallon barrels for $5 apiece. I sawed off the top of one to make a huge open bucket (I really love reciprocating saws- just sayin’) and twisted a threaded hose bib into a hole I drilled near the bottom of the barrel side wall. I sewed a 3-foot circle of window screening into a flow-through “bonnet” to keep mosquitoes out of the water, then placed my new “surge tank” on top of a few cinder blocks stacked outside my laundry room. I was ready to start
reusing my washing machine greywater. Well, almost. Unless I wanted to do laundry with the drain hose from the washer running out an open window, I had to cut through the stucco of the laundry room wall, run a section of 2” PVC pipe through (angled to run into the tank), then patch up the holes and hang the washing machine drain hose in the PVC pipe. Did I mention my husband is tolerant? And helpful? I did most of the work myself, but even minor demolition and construction just goes better when someone with testosterone-influenced biceps is around to help out.

My initial results were promising. My front-load washer generated about 10 gallons of water per medium load, and the five members of my family generated about 5-7 loads of laundry per week. Whenever several plants in the yard needed watering, I put on my gardening clogs, went outside, opened up the tap, filled my watering can with murky-looking water, and watered my plants. I always washed my hands afterwards. Nothing died. Nobody got sick.

It worked, but it wasn’t ideal. The one-foot-elevation of the barrel didn’t provide much pressure, so the can filled sloooooowly, and I still spent too much time slogging back and forth to the front yard. Besides, greywater that sits for more than a day gets stinky, especially in warm weather. As soon as my backyard garden hose sprung a big enough leak that it was no longer useful for the kids’ sprinkler toys, I moved it to the spigot on the tank and ran the end under the side gate to the front yard. The low pressure of the tank didn’t cause any leakage, and I could simply leave the tap open and move the end of the hose from plant to plant as needed so the greywater never got a chance to grow fetid. This also meant that the greywater went directly to the root zone of plants, rather than splashing on the foliage where the ultra-fastidious might worry about spreading contamination.

Three years later, I still do. Nothing died. Nobody got sick. And I get compliments on the yard all the time.


11 responses to “Laundry and the Low-water Landscape: Greywater Harvesting and Reuse, Part II

  1. mfranti May 17, 2011 at 7:59 pm


    I’m so inspired. Again.

  2. reader Rachel May 17, 2011 at 8:50 pm

    I am so impressed. I wonder if I could convince my husband to let me move the washer out of the basement so it would be easier to access the grey water. I know exactly where I would put it…

  3. Nicole I May 18, 2011 at 3:39 pm

    Does your cost analysis include sewer charges? Our water charges in Portland are $2.73/100 cubic units which tend to make you think that it wouldn’t be worth it. BUT, our sewage charges are just shy of $7. This means that each 100 cubic units essentially costs $9.70 – an enormous difference.

    I’m impressed that you are using your washing machine water. Can you verify if your washing machine is on your main level? Ours is in the basement and I’ve heard conflicting reports as whether or not pumping up 8 feet is a bad idea (wear and tear wise on the pump) or not.

    Someone has to have a good solution for the bath tub water. This is actually the cleanest of grey waters… and the one I want. hmmmm.

  4. Jessica May 18, 2011 at 8:52 pm

    @Nicole- yes the washer is on ground level. For some reason, most homes in so Cal do not have basements. I did the calculations on the cost back in 2009 (this post was modified from a journal entry of sorts) and I don’t remember if it included the sewer charges, but yes, they should definitely be included in any thorough cost analysis. I know I factored them in when I convinced my husband that we should invest in a big ‘ol rainwater tank in 2010- but I still didn’t win him over on that one until I pointed out the wisdom of having an emergency water source in a fire- and drought-prone state. Now that water and sewer rates are rising, maybe I can convince him I need another one for Christmas!

    If my washer were in the basement, I think I would have a barrel surge tank for the outflow in the basement, then a separate pump in the barrel that I could turn on as needed. Maybe your usual basement sump pump could do double duty? I have seen people rig up small pumps and hoses to dump their bathwater outside. I’ve used it for flushing before, a la my previous post. But I agree, someone’s gotta have a brilliant solution just bursting out of their brain on that one.

  5. mfranti May 18, 2011 at 8:58 pm

    “For some reason, most homes in so Cal do not have basements.”

    For the same reason you wont find brick houses and unreinforced masonry buildings.


  6. Nicole I May 18, 2011 at 9:58 pm

    Yeah, I’ve been thinking about a surge tank and additional pump. Hmmm. Maybe an inline pump. Hmmm.

    The California comment triggered another thought. CA has the most lenient greywater rules. While this setup is likely legal in CA, it is may be illegal elsewhere. For instance, the proposed draft rules in Oregon say greywater from the interior of the house (anything but rain runoff) must be discharged below soil.

  7. mfranti May 18, 2011 at 10:02 pm

    Going 7 miles over the speed limit is illegal, too. 🙂

    I always pour my dishwater on landscaping plants. If I had Jessica’s setup, I’d use my laundry water and wouldn’t think to ask permission.

    Though, it’s good to have the heads up.

  8. Jeremy May 20, 2011 at 11:26 am

    We tried using greywater from the bathtub for a while, but it was a pain in the but and our carpets were soaked. I love this laundry idea. while our laundry area is in the middle of the house, there is already a line running outside for the dryer’s exhaust, I wonder if I could fit a pipe in there somewhere to take the water from the washer out as well.

  9. Jeninlb May 22, 2011 at 9:37 pm

    Cool idea. Wish there was a way to pressurize the catch basin so the water could be spread around the way a hose normally works.

  10. Mike H. August 30, 2011 at 3:14 am

    This is a good idea. Too many homes are built without any thought of using greywater. Yes, some plant don’t deal with soap well, but for others, it’s fine. And, Craig Barrett, Sr. Exec, then CEO of Intel, was pushing low flow toilets. Yes, some people fly off the handle for Gov’t. to require *anything*, but I don’t see it being very Patriotic to waste resources.

    And, some shale gas drillers help themselves to water from creeks & even fire hydrants, without permits or metering, so be aware if you live in those areas:

  11. patti75835 January 10, 2012 at 11:28 am

    I bought a big plastic utility sink on tall legs from the local hardware store. I added a faucet for fresh water if needed, but my real use for it is to collect my laundry water. I pulled the washer drain pipe out of the wall connection and it goes to my sink. I have a slab, so there is no plumbing. To solve that, I searched and finally found a 10 foot section of plastic black pipe tubing, about 2 inches in diameter and I bought two of those and glued (with pvc glue) them together, so now I have 20 feet of piping. I attached one end to the underneath of the sink with pvc glue and brackets and when its laundry day, I open the garage door and roll the black pipe out into the yard. I then use the lid from a plastic storage container and thats where the end of the pipe sits. I found that if the pipe empties into the yard directly, there is a little erosion and a little hole where the water was going. The storage lid kind of dispurses the water more evenly. The pipe can be moved to different areas of the front and side yard and all water, wash and rinse goes out there.

    Another way to save water is to wash the white clothes first, t shirts and things. Put a stopper in the plastic sink during the rinse cycle and then wash darker clothing and use the rinse water from the white rinse as this load’s wash water. There is still a bit of soap and fabric softener in it, so you even can use less of that, then when it rinses, be sure to remove the stopper so it can go into your yard.

    I’m not saving much. Maybe 5$ a month, but its the environment I hope I am helping. I use soaps with no phosphates, but I didnt realize salts are in the soap. (Or is that what they call phosphates?) And I’m getting lots of exercise moving the pipe in and out of the garage and scooping buckets of water when I reuse it in the second load.

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