Gray Water Systems

What is Gray Water?

Gray water is untreated waste water that has not been contaminated by any toilet discharge, has not been affected by infectious, contaminated, or unhealthy bodily wastes, and does not present a threat from contamination by unhealthful processing, manufacturing, or operating wastes. Gray water includes waste water from bathtubs, showers, bathroom washbasins, clothes washing machines, and laundry tubs, but does not include waste water from toilets, kitchen sinks, dishwashers, or laundry water from soiled diapers, due to potential health issues.

Gray Water Systems

Using gray water is an excellent way to recycle and conserve water, and can help you reduce potable water consumption. Your indoor water can be reused as gray water, providing a constant source of recycled water for irrigating landscape including fruit trees, but excluding vegetable gardens.  Typical gray water systems are onsite waste water systems that use untreated gray water for subsurface landscape irrigation through the use of mulch basins, disposal trenches or subsurface drip irrigation fields.

Basic gray water systems using wastewater from a single clothes washer in a one- or two-family dwelling may be installed without a permit provided certain requirements are met.  Simple and complex systems that affect existing plumbing, electrical, mechanical or building systems require a permit, as well as any system that includes a potable water connection or the use of a pump.

Gray Water Regulations

Gray water systems are regulated by the City of Encinitas in accordance with Chapter 16 of the California Plumbing Code (CPC).  Additionally, the California Regional Water Quality Control Board - San Diego Region (Regional Board) regulates all discharges of waste water to land.  The Regional Board has issued a waiver (Waiver No. 1 of Order No. R9-2014-0041) that allows discharge of gray water provided a Notice of Intent (NOI) to discharge is filed with the Regional Board.

Gray Water Systems in New Single-Family Homes

Effective September 20, 2015, all new single-family homes must be pre-plumbed with gray water plumbing to all gray water eligible discharge sources and with a stub-out convenient for connection to the landscape irrigation system.  Refer to Ordinance 2015-11.

More Gray Water Information

The Residential Gray Water Irrigation Systems FAQ document provides more information and guidance on the installation and regulation of gray water systems in Encinitas.  You can find basic information on gray water systems, City regulations, water districts’ roles and the Regional Board’s role, as well as useful links to information on gray water.

The Residential Gray Water Irrigation Systems Submittal Requirements document provides information on submittal requirements for systems that require permits as well as standards and requirements for systems that do not require permits.

Fee Waiver

On September 23, 2015 the City Council adopted Resolution 2015-57 waiving fees for installation of gray water systems in existing one- and two-family homes.  Systems that require alteration of mechanical systems or require building modification would be subject to fees for those portions of the systems.

Related Links

California Plumbing Code (CPC) Chapter 16
California Regional Water Quality Control Board - San Diego Region (Regional Board)
Notice of Intent
Olivenhain Municipal Water District
Ordinance 2015-11
Resolution 2015-57
San Diego County Water Authority
San Diego Sustainable Living Institute
San Dieguito Water District
Waiver No. 1 of Order No. R9-2014-0041