excerpted from an LA Times article article-http://latimesblogs.latimes.com/greenspace/2009/07/california-may-adopt-more-lenient-graywater-code-in-august.html
The 12 guidelines for clothes washer and/or single-fixture systems are:
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 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.
4) The gray water shall be contained on the site where it is generated.
5) Gray water 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) Gray water may be released above the ground surface provided at least two inches 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 used to wash diapers or similarly soiled or infectious 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 hobbyist or home occupational activities.
11) Exemption from construction permit requirements of this code shall not be 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. 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 gray water system.