Greywater central  | Greywater how-to books & videoCommon greywater mistakes  | Greywater policy center | Grey water Q&A


Current California Graywater Standard:
2016 CPC Chapter 15 Alternate Water Sources for Nonpotable Applications
(formerlly CPC 2013 Chapter 16 Nonpotable Water Reuse Systems)

Latest California Greywater Standard
links to history, analysis of significance, science, government web sites, and suggested improvements

For regulators, inspectors, elected officials, building departments, health departments, builders, homeowners, and activists.

On this page:

California's Current Greywater Standards

(There is a fully annotated version with interpretation and suggested improvements in our  Builder's GW Guide-book).

PDF of current greywater-rainwater code

Full Plumbing Codes

Printable CA codes from Public



Part I


This part is applicable to occupancies under the authority of the Department of Housing and Community Development as specified in Section and is intended to:

  1. Conserve water by facilitating greater reuse of laundry, shower, lavatory and similar sources of discharge for irrigation and/or indoor use.
  2. Reduce the number of non-compliant graywater systems by making legal compliance easily achievable.
  3. Provide guidance for avoiding potentially unhealthful conditions.
  4. Provide an alternative way to relieve stress on a private sewage disposal system by diverting the graywater.

Standards for Permit-Free Clothes Washer/ Single Fixture System

Systems that meet these standards do not require a permit or inspection:

1502.1.1 {HCD IJ Clothes Washer System. A clothes
washer system in compliance with all of the following
is exempt from the construction permit specified in
Section and may be installed or altered without
a construction permit:

(1) If required, notification has been provided to the
enforcing agency regarding the proposed location
and installation of a gray water irrigation or
disposal system.
(2) The design shall allow the user to direct the flow to
the irrigation or disposal field or the building sewer.
The direction control of the gray water shall be
clearly laheled and readilv accessible to the user.
(3) The installation. change, alteration. or repair of
the system does not include a potable water
connection or a pump and does not affect other
building, plumbing, electrical. or mechanical
components including structural features, egress,
fire-life safety, sanitation, potable water supply
piping, or accessihilitv.
Note: The pump in a clothes washer shall not be
considered part olthe gray water system.
(4) The gray water shall be contained Oil the site
where it is generated.
(5) Gray water shall be directed to and contained
within an irrigation or disposalfield.
(6) Ponding or runoff is prohibited and shall be
considered a nuisance.
(7) Gray water may he rcleased above the ground
surface provided at least two (2) inches (51 mm) of
mulch, rock. or soil, or a solid shield covers the
release point. Other methods which provide equivalent
separation are also acceptable.
(8) Gray water systems shall be designed to minimize
contact with humans and domestic pets.
(9) Water llsed to wash diapers or similarly soiled or
in/ectiolls garments shall not be used and shall be
diverted to the building sewer.
(10) Gray water shall not contain hazardous chemicals
derived from activities such as cleaning car parts,
washing greasy or oily rags, or disposing of waste
solutions from home photo labs or similar
hobbiest or home occupational activities.
(I J) Exemption from construction permit requirements
of this code shall not he deemed to grant authorization
for any gray water system to be installed
in a manner that violates other provisions of this
code or any other laws or ordinances of the
enforcing agency.
(12) An operation and maintenance manual shall be
provided to the owner. Directions shall indicate
that the manual is to remain with the building
throughout the life of the system and upon change
of ownership or occupancy.
(J 3) Gray water discharge from a clothes washer
system through a standpipe shall be properly
trapped in accordance )with Section J 005.0
1502.1.2 Simple System.


How to Resources:



What Local Jurisdictions Should Take into Account Before Amending This Standard

The new California standard is the culmination of an extensive stakeholder review process with extensive input from building officials, health officials, inspectors, industry and environmental representatives.

Some local jurisdictions are considering altering the new California greywater code in ways that are likely to have the opposite of the effect desired.

Before altering the standard, it would be wise to:

  1. Gain a complete understanding of the history and realities of California greywater use, not just the one in 10,000 systems that were built with permits, but the other 1.7 million existing systems
  2. Get a complete view of the risks and benefits of greywater reuse.


A point of much discussion is the question of whether the most basic class of systems should be

  1. allowed to be built without permits if they meet standards, as in AZ, NM, and TX
  2. registered, or—
  3. permitted and inspected

In an effort to maintain control, California attempted "3" the past 20 years. However, Californians do not want to pay $100 for a permit for a system that has less than $100 in parts.

The unintended consequence was to drive greywater reuse completely outside of reach of the potential positive influence of government agencies, building inspectors, licensed professionals, or experienced installers. Virtually all the state's 1.7 million greywater systems are homeowner-built systems that feature uncontained surface application of greywater.

This giant experiment —

  1. inadvertently proved that it is very difficult to get sick from greywater; there hasn't been a single documented case of greywater-transmitted illness in the US.
  2. proved that pushing too hard for control causes a loss of control.

There is very little traction for greywater regulation. The best approach is with a light hand, focusing on:

The current standards take this approach, by requiring no permit for the most basic systems, and providing for increasing oversight of increasingly complex or worrisome systems.

For more details and supporting facts and figures on the above, please read these two documents:

Full text of Art Ludwig's testimony to the BSC

Handout to BSC (PDF) includes reasons to have standards but not require a permit for simple systems


Notification/ Registration of Greywater Systems

Notification/ registration of greywater systems (or a certificate of negative declaration) have been proposed as a possible compromise between permitting and not permitting. The current standard allows this option:


If required, notification has been provided to the Enforcing Agency regarding the proposed location and installation of a graywater irrigation or disposal system.


At first I was excited about this, but then I realized that this would probably be less satisfactory than either of the other scenarios.

I assume that these are the goals of registration:

  1. Better systems
  2. Better understanding of what is happening in the district
  3. Greater control
  4. Increasing knowledge base concerning what types of systems, uses, waste streams, application rates, treatment devices are most effective for managing graywater reuse.
  5. Encouraging communication between graywater system users and the public sector
  6. Establishment of a user database so new developments in graywater reuse can be made available to those who have participated in the notification process

Registration is likely to have the opposite of the desired effect for every one of these goals. Here's why:

  1. The chilling effect of a registration requirement on professional installations is probably worse than requiring a permit. Homeowners would perceive it as an open invitation to inspect the site at any time in the future. The likely result is that installations will be done by unskilled homeowners without benefit of professional assistance in order to avoid registration. In many areas, the reduction in numbers of professional installations may cross the threshold of viability of greywater installations as a business (it is a low margin business to begin with), with the result that even those that would be happy to have their systems done professionally and registered won’t have the option of professional help. The result: worse systems than would be achieved under the "standards but no permits" scenario (which eliminates all barriers to installation by licensed professionals).
  2. With the vast majority of the greywater systems driven underground, the sample will be of little statistical or other value. Ditto for the rest of the points...with 9999 out of 10,000 installations unregistered, little benefit will be gained.

If your jurisdiction is interested in registration, here's an approach that, while it aims a bit lower, I think will actually hit the targets: (I've written it here in the form of suggested language for the state standard, it certainly would be allowed under the current language quoted above)


At the Enforcing Agency’s discretion, the Enforcing Agency may inspect clothes washer and/or single fixture systems concurrent with an inspection on the property for another purpose, an enforcement action for another purpose, or an otherwise required inspection on sale of a property.


Here's the details:

  1. When permitted new construction or remodeling includes a greywater system, the greywater system must be registered to add to the county's experimental best practices database. The trigger could be set anywhere desired, from any permit at all—re-roof your house, greywater system gets registered—to highly selective—new construction, for sure, and maybe major replumbing.
  2. Greywater systems could be voluntarily registered
  3. When there is a complaint, the greywater system would be registered, and this form of registration unlike the others, would constitute justification for follow up visits.

So ...I think this gives the best of both worlds:

  1. whenever an inspector is already at a site, the county would get another entry in their database. Peoples bubble of privacy is already penetrated at this point, so it wouldn't seem so calamitous. The sample could include all new construction and remodeling, adding sizable, non-self selected chunk of data to the system that had just one independent variable (a permit for something else) rather than the highly biased sample you'd get from people who for some reason came forward for with mandatory registration.
  2. Voluntary registration would presumably get a few exemplary systems out of the woodwork and into the database, perhaps systems installed by professionals looking to add credibility to their work.
  3. Complaint based-registration would get samples from the opposite end--lousy, problematic systems—into the database, and would provide an incentive to people to keep their greywater noses clean, and a mechanism for tracking, monitoring, and actively abating that small percentage of systems that doubtless contribute disproportionately to lowering the average performance.

If your jurisdiction is interested in going this route, please  Email us ; I'd be interested in helping develop optimal language.


Art Ludwig


Links to California Greywater Resources

Policy resources



If you find this information useful, please consider leaving a donation in our  Tip jar.