Graywater Systems

L2L systems only reuse water from a single domestic clothes washer in a one- or two-family residential home. L2L systems do not include pumps, tanks, or affect the building's plumbing, electrical, or mechanical components including structural features, egress, fire-life safety, sanitation, potable supply piping, or accessibility. Compared to other types of graywater systems, L2L systems have the simplest and most affordable installation.

Simple and complex systems differ from L2L systems because they can reuse water from a clothes washer, bathroom sink, shower, and/or bathtub. These two types of systems alter the building’s plumbing and can include surge tanks, filtration systems, pumps, and installation of a backflow prevention assembly.

These systems are considered either simple or complex based on the amount of graywater they generate per day. Simple systems generate less than 250 gallons of irrigation water per day, while complex systems generate more than 250 gallons per day.

• Graywater systems must be designed to minimize contact with humans and domestic pets.
• Graywater systems cannot be connected to drinking water piping or fixtures. Customers are not allowed to use an existing below ground irrigation system that is connected to the house drinking water supply. Graywater must be applied through a separate above ground or sub-surface irrigation piping and emitters that are covered by at least 2-inches of mulch, rock, or soil.
• Graywater piping must be clearly labeled and readily available to the user.
• A valve must be installed to divert flows between sewer system and the above ground or sub-surface irrigation piping.
• An operational and maintenance manual must be provided to the property owner and remain with the system.

• Water used to wash diapers and similar soiled garments must be diverted to sewer system.
• Graywater cannot contain hazardous chemicals such as cleaning from car parts, washing greasy or oily rags, or disposing of waste solutions from home photo labs or similar hobbyist or home occupational activities.
• Graywater systems cannot be used to irrigate root crops or food crops intended for human consumption that comes into contact with soil.
• Graywater cannot be used for spray irrigation.
• Graywater cannot pond, runoff or discharge to the street gutter, storm drain system, or surface water.
• Graywater must be contained on the site where it is generated.

L2L systems do not require any permits provided the system meets the California Uniform Plumbing Code and any applicable City Code requirements. If you are unsure if your project requires a permit, contact your city's permit center.