Providing recycled water to MMWD customers—350 and counting in northern San Rafael—requires a separate water treatment and distribution system to ensure there are no cross-connections with potable water—that is, recycled water doesn’t mix with drinking water. This separate distribution system is made up of 25 miles of pipeline, three storage tanks, four pump stations and one treatment plant. Although it is an expensive system to build and maintain, it helps reduce demand on potable water.
The majority of our recycled water customers use the water for irrigation, and about 100 customers have dual-plumbing that allows them to use the water for other uses such as toilet flushing, washing laundry and cars, and air conditioning.
Each November and December MMWD’s Reclamation Specialists Pat Feht and Rich Caboara inspect the approximately 100 dual-plumbed facilities to make sure that each is functioning properly and labeled correctly. (See photos from this year’s inspections here.) The labeling requirements for recycled water are very stringent. For example, all meters and meter boxes must be painted purple; all pipes delivering recycled water must be identified with purple Mylar tape printed with the words “Caution: Reclaimed Water. Do Not Drink”; and all valve handles must have intact breakaway seals. Special signage is also required. Any facility using recycled water must post signs at the business entrance and at the location where the recycled water is used, such as within a bathroom where the toilets are flushed with recycled water or a laundry room where recycled water is used.
In addition to conducting these annual inspections, Pat and Rich take water samples weekly throughout the year to assure that our recycled water meets strict water quality criteria. Our recycled water is treated three times before distribution and is crystal clear, odorless and free of harmful bacteria. It is similar in quality to swimming pool water.
MMWD has been at the forefront of providing recycled water and creating and supporting legislation to promote its use. We continue to explore non-agricultural uses for recycled water, just as we continue to promote conservation of potable water.