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California Building Standards Commission
Graywater Testimony from Art Ludwig


My name is Art Ludwig

I’m a Graywater researcher and educator.

I have 29 years experience in the field.

I’ve reviewed thousands of gws and developed several improved designs which I’ve published into the public domain.

I am the author of the two top selling plumbing books on Amazon, one of which is on greywater.

I’ve been hired by NY, NM, Santa Barbara and others to improve greywater policy.

I’m here at the behest of the City of Santa Barbara Water Resources Division to request that you approve this new standard, without amendment.


I’d like to share a few salient greywater facts and figures:


·      California currently has 1.7 million greywater systems

·      Of these, one in 10,000 has a permit.

·      Greywater has less than a thousandth the pathogens of wastewater.

·      Thus, greywater systems can be a thousandth as effective at containing pathogens as septic or sewers and still be safer than septics or sewers

My written comments include the citations and calculations behind these figures.

Common sense standards, and no permit is the best practice for greywater regulation—Why?


1.     First, it makes sense to use regulatory resources on risks that matter.  Below a certain impact threshold, exemption from permits is common in codes. Greywater’s health impact is so low it has not reached the detectability threshold.

There have been a billion greywater system user-years of exposure in the US, and not a single documented case of greywater-transmitted illness.

2.     Second, the permit requirement deters licensed professionals from improving our stock of greywater systems.

3.     Realistic standards will enable greywater players to openly develop best practices. Resources that have been going into hiding greywater systems could go into upgrading them.

4.     Greywater permits are a waste of time and money better spent on the enormous emerging risks we face, such as those from climate disruption and groundwater depletion.


If you think about it, 

The most dangerous thing you can possibly do with greywater is stir in lots of feces and then overload a septic or sewer with it.



If there is anyone here to speak against adopting this standard, I have a specific request: Please explain how overflowing septics are better than permit-free greywater systems.


I am available to answer questions about the science behind these facts and figures, or to review the reliability of other information presented to the commission. I hope the BSC will take heed of this trend among their peers and approve HCD’s new standard as submitted.


Regulators in AZ, NM, TX, NV, MT, and OR have or are abandoning gw permits in favor of common sense standards. After immersion in the topic, the folks at HCD and the Governor’s office are, too.


Half of all carbon emissions are from buildings. Buildings built to current codes are sucking the groundwater out from under California. Greywater permits are part of an outdated system that  focuses on microscopic risk as our species is engulfed by huge, emerging risks.


Common sense greywater standards are a step towards building systems that support human life sustainably.



Thank you.


Handout to BSC, including reasons to have standards but not require a permit for simple systems

First-hand perspective of the meeting

From Laura Allen, Greywater Guerillas

Yesterday the Building Standards Commission voted to pass the new
California greywater code (Chapter 16 in the CA Plumbing Code).

This was passed as an emergency measure due to the drought and water
shortages faced in the state.

The code will be going through a public review process for the next 45
days. The opposition (the plumbing union, and some building officials)
will be writing in negative comments about the code. People who support
having a simple, safe, and accessible code will also need to write in
comments to help ensure the code is not changed during the comment period.

We'll send you more info in the upcoming weeks about how to provide input
into this process.

Thanks you again to everyone who has written and called in to the
Department of Housing and Community Development to share your view point.
They listened and responded in this new code. We couldn't have done this
with out the huge amount of support for simple greywater regulation coming
from you all.

Importantly, the CA department of Public Health spoke in full support of
the code, citing water shortages and degrading quality of fresh water
being a much greater health concern than any potential issue with

Lastly, local jurisdictions will be allowed to make greywater more
restrictive, which many will want to do. Now is a good time to start
conversations with your cities and counties about how they can help
support safe and accessible reuse of greywater.

Summary of the new code (as it's written now)
*no permit needed for a washing machine system if the system followed
health and safety guidelines outlined in the code
*no permit for a singe fixture (one shower) if guidelines are followed
*mulch basins allowed (instead of gravel)
*other systems are separated into "simple" and "complex" depending on the
quantity of water. There are less requirements for "simple" systems.
*depth of discharge is 2 inches under mulch (it used to be 9" under dirt)