Graywater includes wastewater from bathtubs, showers, bathroom sinks, clothes washers, and laundry tubs. Instead of sending this water down the drain, graywater systems divert water from these sources for reuse on site, most commonly for landscape irrigation. In addition to saving water, graywater resuse can provide a reliable source of irrigation water during drought and lessen the burden on local sewer systems.

Graywater systems are governed by California Plumbing Code as well as Marin County and local jurisdictional codes. Under state code, graywater does not include wastewater from kitchen sinks or dishwashers, or water contaminated by any toilet discharge.

What's New: Graywater Ordinance Effective February 1, 2016
MMWD's Board of Directors has adopted Ordinance No. 429, which requires applicants for new water service and applicants requesting an enlarged water service for substantial residential or commercial remodels to install a graywater recycling system to reuse the maximum practicable amount of graywater on site. The new requirement supports the district's ongoing efforts to reduce demand on the potable water supply during the current drought and beyond. For more information about the requirement, please see the documents below or contact Engineering Services at 415-945-1530.