This post is getting long with amendments, so for the hurried reader, our findings in summary. Please read the longer post for details:
As of today, we are still only able back three products without reservation for use in greywater:
• Oasis Liquid Laundry Detergent
• Bio-Pac Laundry Detergent
• soap nuts
ETA 8/14: Also, it looks like Fit Organic Laundry Detergent is safe as well. Thanks, Judy!
Sorry folks, I know that’s not a lot in terms of choice.
The following eco-friendly detergents are often listed as greywater compatible, but we have reservations about them. We recommend you research these products more on your own, and consider your own greywater system as well as the specific plants and soil you are irrigating before deciding whether these should be used or not.
Ecos: Contains sodium coco sulfate
Vaska: Has a D+ rating on the Environmental Working Group’s product safety database.
Lifetree: Has a pH level of 7
Dr. Bronner’s liquid soap: Fine for greywater use in general, but it simply is not a laundry detergent–it’s castile soap. You can wash your clothes with it, but the results won’t be spectacular.
This is the original post:
When your laundry water is going to the soil instead of to the sewer (or a septic tank) you need to make sure that detergent is friendly to soil life. All of your basic, big brand detergents are a no-go for greywater.
Even the various eco-detergents, even ones marked “biodegradable”, are not appropriate for the soil because they are essentially salt-based (look for the word sodium on the label). They play well with aquatic life, bless them, and they’re a fantastic alternative to more toxic detergents if your laundry water is going to the sewer, but they aren’t good for soil microorganisms. Surely you’ve heard that salting the land is a bad idea? You don’t want to salt your garden.
It’s worth adding that the drier your climate, the saltier the soil, because there is not enough rain to help percolate it away–so if you live in a dry climate it’s even more important to be careful with salts.
Homemade detergents–the ones based on soap and washing soda–are also not an option, again because of their salt content.
Salt is always my first concern, but laundry detergents can contain a host of other ingredients you just don’t want in your soil. Here’s a list of things to avoid which I lifted from Brad Lancaster’s eminently useful site (he in turn, lifted them from the State of California’s Department of Water Resources) Check out that link to Brad’s site for more good info. on greywater detergents, and all things greywater in general:
According to State of California Department of Water Resource’s Graywater Guide: Using Graywater in Your Landscape , specific ingredients to avoid include:
-chlorine or bleach
As far as I know with the information I have today, this leaves us with three detergent options. If you know another detergent which is specifically formulated for greywater use, please let us know.
1) The first is a laundry detergent called Oasis Biocompatible, sold by Bio Pac. This is what we use. It’s a basic, colorless, odorless, super concentrated liquid detergent, specifically formulated for greywater use. It works very well, but doesn’t have the bells and whistles of “whiteners” and “brighteners” found in grocery store brands. To me, this is a plus. It is not found on supermarket shelves. I have seen it in some health food stores, but we order it online. This is not too bad of a deal because it is concentrated, so a gallon bottle lasts a long time.
I’ll add that sometimes it can’t be found online, and this is frustrating. I’d ask the folks at Bio-Pac to find some means to ship it directly to the consumer, as local sources can be hard to find.
2) Bio Pac Ultra Liquid Laundry Detergent is sort of a sister product to Oasis, and though I haven’t used it, I think it’s very similar. We’re going to do some research and report back on the difference between these two products.
2) The final option is soap nuts. Soap nuts are the dried fruit of the soap nut tree–they look a little like a cross between a date and a hazelnut. They are full of natural saponins (soaping agents) which are released in the wash. These saponins have been tested and don’t harm soil life.
You just drop 3 or 4 of the nuts into a little muslin bag (which comes in the box), and throw that bag in the wash with your clothes. They activate better in hot water, so some people will opt to soak the bag in a cup of hot water first–like making tea–and then dump the water and the bag into the wash. Other people stew the nuts in water and make soap nut tea, which can then be used like liquid soap, for both hand washing and laundry. There’s lots of info online about soap nuts if you poke around a bit.
I just remembered that I posted here back in 2010, asking for feedback on the nuts, and got lots of it. So you might want to check that out.
If you’ve never heard of soap nuts, the whole idea might seem strange. But remember, all soap really does is help water work better, and they release soap. The real washing power is the agitating water in your machine.
Incidentally, Oasis, Bio Pac and soap nuts are fine for HE washing machines.
ADDENDUM: Option #3: Thanks to commenters Kay and Matt, I’m going to add a 3rd product to this list: Ecos Laundry Detergent. It claims to be greywater safe, I checked the ingredients and saw no salts, and Matt says he’s used it for a year successfully. Sounds good to me! Also in the plus category, this Ecos seems easier to find in stores than Oasis. Addendum to the addendum: Ecos contains sodium coco sulfate which some folks do not consider biocompatible.
ADDENDUM 6/5/15: I’ve been doing some more research on the topic, and sad to say, I have only negative results to add to this list:
Some greywater lists include Vaska laundry detergent. Unfortunately, it scores a D+ on the Environmental Working Group guide. As far as I can tell, some of the low score is attributable to non-disclosure of ingredients, but still, it causes me concern.
Lifetree liquid laundry detergent is a bio-degradable product which is safe for septic systems, and which also appears on some greywater lists. However, none of their product information states specifically that it may be used for greywater, so I wrote to them. They kindly replied in some detail, explaining that Lifetree contains no salts, but it does have a pH of 7.
They recommended I consider the effects of that level pH on the area I am irrigating with greywater–and I liked this, because this response acknowledges the complexity of the issues. This pH may be acceptable in some situations, and on some types plants, but not all. For us in the West, our soil pH is already quite high, so Lifetree is not a possibility for us.
Pure castile soap, like liquid Dr. Bronners, is okay for the soil, but it doesn’t really work as a laundry detergent. You can use it as such for the occasional load, but you will find your clothes turning grey with extended use. Sometimes, however, if I’m dealing with a musty or stinky load of laundry, I’ll put a squirt of scented Dr. Bronners into my machine along with my Oasis or soap nuts, since Oasis is odorless, and soap nuts have a bit of an organic scent (which doesn’t linger on the clothes).
You also need to be careful with laundry additives when your laundry water is going to the garden. No bleach, obviously. Bleach alternatives, like OxyClean, are also suspect because they are often based on sodium percarbonate. Check the ingredients and scan for the word sodium. If you see it, it’s best to avoid the product. For this same reason, no baking soda (sodium bicarbonate) either, or washing soda (a sodium salt of carbonic acid).
Vinegar is okay, lemon juice is okay, and I don’t see how small amounts of hydrogen peroxide would hurt anything, though I’d want to do more research if I made it a regular part of my laundry rituals. I’m suspicious of the various specialty stain removers. If you’re just squirting one spot on a shirt, obviously it will be greatly diluted in the wash water, but really, who knows what is in these stain formulas? When you use greywater you really learn the meaning of “closed loop” — you have to live with what you put out there. So, the decision is yours in the end.
So how do you use your “nuclear option” type laundry additives? Read on, dearies.
The Importance of a Three Way Valve:
It is well worth the time to install a diverter valve by your machine which allows you to choose whether your wash water will go to the sewer or the garden. If you have one of these, you can do loads with bleach or what-have-you and send that water to the sewage treatment plant.
Also, if you are washing diapers, this valve is an absolute necessity. All diaper wash water should go to the sewer. Soil is a great cleanser, but you don’t want to push your luck by depositing fecal matter around your garden.
(Addendum here, too: I spoke a little too absolutely above. It is possible to reuse that water, but you need to do so very carefully. Diaper water is blackwater, not greywater, and needs to be handled in specific ways Perhaps we’ll do a separate post on that later.)
Finally, during periods of heavy rain you may just prefer not to send any more water to the garden, and this allows you to make that choice.
A few words about other greywater applications:
If you’re using greywater from your shower, most soaps and shampoos are okay. Though again, I’d remember the closed loop principle and try to use soaps and shampoo from the more natural end of the spectrum. Again, good ol’ Dr. Bronners, soap or liquid form, is something I’d feel good about sending out to the landscape.
Bio Pac also makes a concentrated soap which is a sister to the Oasis Detergent called Oasis Dishwash/All Purpose Cleaner. This is an all purpose soap that you can even use in the shower. This would be a good product to use for more casual water recycling–so when you’re cleaning house, say, you can safely dump a bucket of dirty water outside and know that it won’t harm your garden.