California Greywater Regulations

California’s greywater code is found in Chapter 15 of the California Plumbing Code (CPC) (as of 2017, previously it was in Chapter 16) . Under the current code washing machine systems can be constructed without a permit in single family homes (1 or 2 units), so long as 13 guidelines are followed (see below). Other types of systems require a permit in the state.

You can download the greywater chapter here. Note that Chapter 15 includes regulations for both “HCD” – the residential code, and “BSC”- the commercial code. If you are building a system in a residential home disregard any requirements that start with “BSC”.

Requirements for no-permit systems in California

Since 2009, the California code does not require a permit or inspection for washing machine systems that do not alter the existing plumbing as long as the installer follows the guidelines listed below. (Note that for a few months single fixture systems were included as part of the permit-exempt systems, but were then removed from the code. Between August 4th, 2009 and January 27th, 2010, it was legal to install the “single fixture” system without a permit.)

Summary of requirements:

The system must:

  • have an easy way to direct flow back to the sewer/septic (like a 3-way valve). The valve must  be labeled.
  • send the water to irrigate landscape plantings
  • keep the water on the same property it is produced and follow set-backs listed in the code
  • have a maintenance manual
  • discharge greywater under a 2″ cover of mulch, plastic shield, or stones.

The system must not:

  • contain diaper water
  • contain hazardous chemicals (such as from a home photo lab)
  • have pooling greywater or runoff
  • make greywater accessible to people or pets (such as in an open tub)
  • include a pump (except the washing machine’s internal pump)
  • connect to the potable water supply
  • affect other parts of the building, such as the electrical or structural components.

Text from the Chapter 15 of the California Plumbing Code: Clothes Washer System System

A clothes washer system 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 graywater 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 graywater shall be clearly labeled and readily 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 accessibility. Note: The pump in a clothes washer shall not be considered part of the graywater system.
  4. The graywater shall be contained on the site where it is generated.
  5. Graywater shall be directed to and contained within an irrigation or disposal field.
  6. Ponding or runoff is prohibited and shall be considered a nuisance.
  7. Graywater may be released 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. Graywater systems shall be designed to minimize contact with humans and domestic pets.
  9. Water used to wash diapers or similarly soiled or infectious garments shall not be used and shall be diverted to the building sewer.
  10. Graywater 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 hobbyist or home occupational activities.
  11. Exemption from construction permit requirements of this code shall not be deemed to grant authorization for any graywater 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. Directions shall indicate the manual is to remain with the building throughout the life of the system and indicate that upon change of ownership or occupancy, the new owner or tenant shall be notified the structure contains a graywater system.
  13. Gray water discharge from a clothes washer system through a standpipe shall be properly trapped in accordance with Section 1005.0

The laundry-to-landscape system can be constructed to follow these guidelines and be legal without a permit.