California’s New Greywater Code: Common Sense Legalized!

On the left is our yard which is irrigated by the washing machine. On the right, the neighbor’s yard which is never watered.

This Tuesday the California Building Standards Commission legalized our formally outlaw greywater system. For several years now, we’ve sent our washing machine waste water out to fruit trees in the front yard. The new regulations are a rare common sense moment for our otherwise troubled state government. Let’s hope our current hard times spur more innovation like this. Originally slated to go into effect in 2010, the plumbing code was updated as an emergency measure to deal with drought conditions that have plagued the southwestern US for years. Under the new California greywater code:

1. In most cases you won’t need a permit.

2. Allows discharge into a simple mulch basin rather than the expensive and complicated sub-surface emitters required under the old regulations.

3. No exspensive pumps or filters required!

Here’s the new code as amended (pdf).

Unfortunately the code can be superseded by local municipalities. Plumbers unions opposed loosening the code, no doubt fearing the loss of business. Combined with NIMBYs, they could put pressure on city governments to keep greywater illegal. It’s time for us Californians to be vigilant and start letter campaigns should cities try to restrict our new right to use our greywater.

As for the practical side of this new law, I’d suggest that anyone interested in installing a greywater system keep it simple and low cost. I can’t think of any better resource than Art Ludwig’s book The New Create an Oasis with Greywater: Choosing, Building and Using Greywater Systems and his website Take note of Ludwig’s free open-source laundry to landscape plan.

And don’t forget, Homegrown Evolution is offering a DIY Greywater class on Sunday August 16th at 11 a.m. in Silver Lake (Los Angeles). Sign up here.

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  1. There are legit reasons why “the government” is shy about pumping refuse straight onto the ground. Unfortunately, it is easier to think “black and white” than to think “black, white and gray.”

    Did you know that when filthy water passes through a single inch of clay, it is potable?

    But if you pump your garden full of modern cleaning agents, don’t blame me if your children have a nipple on the back of their necks!

    I think we should absolutely be doing gray water, but not flippantly.

    I recently tried to recycle an empty laundry powder box (nice size!) but the plant was appalled by the chemicals that had leached into the cardboard.

    Please don’t diss your elected officials for trying to play it safe as concerns water and food. They might err, but they’re trying to stay on the side of caution. Advise your readers to do the same!

  2. this is awesome. your yard looks fantastic. and i’m laughing really hard at your neighbor’s yard. oh, neighbor! 😉 at least i convinced her to go solar before i left!

    unfortunately, i’m going to miss your class…but i’ll check out the recommended book!

  3. While *some* of the code changes are a step forward, the requirement for permits for anything other than re-using washing machine water is a wasted opportunity (and then only if an additional pump is not used).

    It is a shame to see Laundry to Landscape being promoted within a code, as people will only be able to undertake this activity by themselves. No manufacturer will go near this concept, due to the significantly increased risk of washing machine failure (and resulting litigation) this method raises.

    For a comments on why Laundry to Landscape causes problems, go to

  4. I have a question. I’ve been using (and loving) the book Making It. While we were in an apartment, we got a lot of use out of making our own bar soap and using the ideas that involve baking soda.

    Now we are in a house with its own septic tank. All the water in the house goes to the yard (we are in SoCal and have alkaline soil), so we will be following Making It’s advice to avoid sodium (baking soda, borax, washing soda). Does that include bar castille soap, which is made with sodium hydroxide or does the bar soap not count because the lye is consumed in the reaction? If so, I’ll have to shed a tear because that soap is amazing. As was the baking soda facial (any alternatives there?)

    Is vinegar graywater compatible? I see I can still use olive oil, soap nuts, and liquid castille soap. What else? Is there a graywater-minded book that you’d recommend so I can keep DIYing?

  5. Hi Joss,

    First, I’m glad you like Making It, and it sounds like you’ve been making some great stuff!

    As to your question, I hope I understand it correctly. Let me know if I don’t.

    You say you’ve got a septic system, but the concerns you’re raising sound more like greywater concerns. Or maybe you’re asking about both? True, septic tank water goes to the yard, eventually, but it’s digested some first, and then it is released deep into the soil. This is different than a greywater system where used water is discharged directly from a shower or a washing machine straight onto the *surface* of the soil. The concerns are a little different.

    As far as the septic tank goes, I’m no expert, having never lived with one, but I believe that you can send baking soda, borax, vinegar, Castille soap–all the usual homemade cleaning ingredients–down your toilet, shower and sink drains into the septic tank.

    I believe this is considered preferable to using harsh chemical cleaners, like bleach. I’m sure other readers will correct me if I’m wrong! But it makes sense–the water from your tank is leaching out deep–not in the top soil, where plant roots are.

    Greywater is different. If any of your drains are running straight to the soil surface you have to be more careful. For instance, our washing machine drains out a hose into the yard, so we have to watch what goes into it.

    And indeed, its not good to send yet more salt directly onto our alkaline soils, so yes, that means none of the sodium-like things should go into greywater: baking soda, borax, percarbonate “bleach”, washing soda.

    However, vinegar isn’t going to hurt your soil. As it’s an acid, it may even be good (balancing) for our alkaline soils, according to Brad Lancaster–and I believe probably not harmful to acidic soils, either, though folks in those areas might want to keep an eye on that if they use tons of vinegar.

    Castile soap is also fine for greywater applications.

    For laundry we use a greywater-specific detergent called Oasis. It’s the only one there is, as far as I know. And as you say, there’s soap nuts, which we use too, but we like the Oasis pretty well. Oasis isn’t “salty”– so using that might help ease your mind re: the septic tank.

    Think about how your household water usage breaks down. I’ve seen graphs of typical US usage, and the toilet is the biggest piece of the pie. The washing machine comes right after. These 2 make up more than half of the daily volume of water that’s going to be expelled into your tank. Neither needs to be a site of heavy baking soda use.

    Also think in terms of dilution. A tiny bit of baking soda used as an exfoliant, or a little more used to scrub the bathtub once a week, compared to the overall daily volume of water used in a household, is seriously just a drop in the ocean.

    Hope this has been of some help!

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