Monday, April 14, 2008

Greyt Detergents for Grey Water Systems


It’s time to turn the illegal valve to use my grey water.

Soap is soap, and most laundry detergents appear to be just the same old detergent. This is fine, unless you have a grey water system designed to irrigate your favorite petunias or roses with the used water from your washing machine. Plain soap, which is made from stuff like animal fat and lye (wood ash), doesn't stop minerals in the wash water from depositing a dirty "smog" on your favorite pure-white undies. So, over forty years ago, Procter & Gamble invented Tide as the first heavy-duty synthetic laundry detergent.

Detergents, fabricated from a variety of chemicals in addition to soap, are engineered to enhance the soap's cleaning capability and avoid graying those undies. But, alas for grey water users, chemicals in detergents are selected with only their clothes-washing capabilities in mind, and with no thought for a thirsty root's sensitivities.

To choose the best detergent for a grey water system, you'll have to read product labels. First, look for the most important element to avoid: sodium. Unfortunately, the amount of sodium in most detergents is impossible to ascertain, and they won't tell you on the 800-consumer phone line because "It's proprietary." As a rule, popular liquid concentrates have much less sodium than powdered detergents, which use cheap sodium-based compounds to bulk up the product.

Next, look for the words boron, borate or Boroteam. Boron rarely kills plants, but it will cause an ugly leaf-margin burn, and can be a real problem with alkaline soils in desert areas. Worse still, once boron is added to soil, it is not easily leached out. So skip all detergents with boron.

Phosphates chemically inactivate calcium, magnesium, iron and manganese without making a precipitate (depositing a grimy "smog" on cloth). These are the chemicals blamed in the 1970s for "ruining" lakes and rivers (it's since been learned that laundry phosphates weren't always the significant culprit). Actually, phosphates are a great ingredient for a grey water system because roots utilize them like a fertilizer. Since a grey water system is managed for the improved growth of the plants, buy a high-phosphate detergent—if you can find one (many states have banned in as an ingredient). Because you'll be monitoring your grey water system, you can make sure phosphates aren't leaching off your property to turn rivers or lakes green.

Finally, watch out for chlorine, which in its concentrated form is a very caustic, toxic and deadly chemical. The amounts of chlorine in detergents are actually quite low, but the prudent gardener will avoid this chemical altogether. (However, I have used chlorine bleach on occasion in the laundry and to remove stains in the bathtub, and have yet to see any visible consequences in my landscape.)

A quick survey of any supermarket will soon reveal a plethora of detergents either useless for grey water or, at best, ambiguously labeled. What's a lawless grey-water user to do? (It's still illegal in most places to use grey water.) I shop for a more “Earth-friendly” detergent but get the full scoop on boron, sodium, and chlorine.

For the latest on grey water developments, see the web site of the Guru of Grey Water, Art Ludwig: http://www.oasisdesign.net/greywater/

Please post a comment - I want to know what you think. Are you an illegal grey water user?


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NOTE: The comments section at the bottom of the post has disappeared. Click on the "___ Comments" button or the title under the "Blog Archives". Thanks, Robert

11 comments:

Anonymous said...

Yup, buckets (for the kitchen water) and a long hose for the washer, just like my grandma used to use out on her back porch... the trees and lawn love it! Nothing yet for the indoor shower, though (summer showers are taken outside)

Anonymous said...

I put a long hose on my washer and water my trees and grass. I recently started using ECOS laundry detergent. It's all natural and is labeled "greywater safe". It works pretty well and it smells great.

Anonymous said...

Yes I have instituted greywater usage again in CA. I colect the rinse water from my washing machine into a 35 gallon rolling plastic trash barrel in the laundry room. I use my plastic sprinkler can to distribute to my trees, flower plants, and grass. I use 7th generation laundry detergent. I do not use greywater on my fruit trees and vegetable garden. I now space out doing loads of laundry to accomodate my plant needs.

StellaRachaella said...

Thanks for the info. I plan to check the site you referenced. I am not a grey water user yet, but I plan to when I move into my first home next month.

Ed said...

I have been using ECOS for about 7 months and I am not happy with how my Strelitzia are responding. The growth seems to be stunted. The grass, shrubs and flowers seem to be doing fine.

Overland to Underland said...

Hi I'm using a home made l'dry powder to use in my grey-water

The ingredients iare;

1 cup velvet soap, 1 cup of washing soda 1/2 cup borax which is grated into a fine powder. I add 1 dessert spoon to my top loader or 1/2 a dessert spoon to front end loader.

It goes directly out onto my lawn, do you think this would be toxic to my soil??

Robert Kourik said...

Sorry, but Borax is very bad for plants. At low levels it can be toxic. Try to use a commercial brand that lists no borax. Robert

Anonymous said...

I love my grey water system! The washer hose empties directly into a 1.5" pvc pipe that goes through my laundry room wall to an underground system. There is about 80' of pipe that is buried in an 18" trench. (I dug this by hand which was really hard work. A ditch witch may be a good tool.) The pipes make a circle around a group of trees. There are T's going vertically to the surface to create cleanouts (capped) and T's going horizontally underground dumping into milkcrates lined with weed barrier fabric and filled with lava rock at the base of each tree. When I moved here the trees were 15years old and stunted by our dry New Mexico climate. Within a few years they'd doubled in size! The system is now 10 years old and going strong. My favorite laundry detergent was Oasis designed, I believe, for grey water systems by a permaculturist. It has been hard to buy locally. Now I use Trader Joe's liquid laundry detergent

Anonymous said...

An ammendment to my post 10/23: the recommended size for the pvc is actually 2" sewer pipe ; the joints needed for the cleanouts/flow diversion (into milk crate and pumice infiltrators) are called "double ell flow splitters"; water runs at a 1/4" angle per foot so dig trenches accordingly; cover the pumice stone with the fiberglass weed barrier(as well as lining the crates) to avoid cave-ins; research before you start --to save work! Your local permaculturists may be helpful. Good luck! It's worth it!

Anonymous said...

An ammendment to my post 10/23: the recommended size for the pvc is actually 2" sewer pipe ; the joints needed for the cleanouts/flow diversion (into milk crate and pumice infiltrators) are called "double ell flow splitters"; water runs at a 1/4" angle per foot so dig trenches accordingly; cover the pumice stone with the fiberglass weed barrier(as well as lining the crates) to avoid cave-ins; research before you start --to save work! Your local permaculturists may be helpful. Good luck! It's worth it!

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