Graywater is untreated wastewater from bathroom sinks, bathtubs, showers and clothes washers but does not include wastewater from toilets, kitchen sinks or dishwashers. A graywater system is a type of onsite wastewater treatment system that utlizes trenches, subsurface drip irrigation systems, and mulch basins to reuse the graywater for irrigation to save water.

The County of San Diego oversees graywater systems for the unincorporated areas of the County only. For incorporated areas (cities), please contact your respective city for graywater requirements. The purpose of regulating the design, installation and maintenance of graywater systems is to prevent public and environmental health nuisance conditions caused by improper installation or maintenance. 

If you live within the unincorporated areas of the County, a clothes washer system, which only utilizes graywater from a single clothes washer, can be installed without a permit provided the system is installed in accordance with the Graywater System Requirements for a Single Clothes Washer. Larger graywater systems, which require more extensive plumbing modifications, require a permit. For more information on graywater systems, please read the following document:  

• Graywater Systems for Outdoor Irrigation Design and Procedures Manual.

Additional information: