Living With a Drip?

Gray Water Systems for Sonoma

Gray water systems can be as simple as a rain barrel collecting and saving roof runoff or as complex as a system plumbed to code that separates out bath, sink and shower water for outdoor landscaping. As varied as they are, all gray water systems have one thing in common: they are designed for more efficient use of potable water.

California's Health and Safety Code, Section 17922.12, defines graywater as “untreated wastewater 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 operation wastes. 'Graywater' includes but is not limited to wastewater from bathtubs, showers, bathroom washbasins, clothes washing machines, and laundry tub". It does not include wastewater from kitchen sinks or dishwashers.

The average family of four produces more than 38,000 gallons of gray water per year, according to John Russell, a landscape contractor and owner of WaterSprout, an Oakland design-build company focusing on gray water and rainwater catchment systems. (See gray water article in San Jose Mercury News.)

That's a significant amount of water, and considering how much summer water use goes to outdoor irrigation, the potential for reducing overall water consumption by reusing gray water to water lawns and other landscaping is equally significant.

Fortunately, Sonoma County recently implemented changes making it easier to legally install gray water systems in the County. The three types of graywater systems currently allowed in Sonoma County are:
1) Clothes washer system (single connection only)
2) Simple system (less than 250 gallons per day)
3) Complex system (more than 250 gallons per day)

BENEFITS of HOME GRAY WATER SYSTEMS

:: Reduces your potable water use up to 40%
:: Reduces your water bill
:: Reduces the County’s energy consumption when less water needs to be processes and transported
:: Reduces demand on Russian River and groundwater sources
:: Helps protect water resources for future generations

THINGS TO CONSIDER

:: Graywater may contain pathogens
although researchers have found no documented cases:: Systems that pond may provide breeding grounds for mosquitos
ponding is avoided with proper mulch basins:: Salt accumulation may inhibit plant growth
use biodegradable soaps exclusively:: Unfiltered systems accumulate solids and may clog system
be careful what you send down the drain or include a filter in your system:: Minimal contact with graywater is recommended
water is diverted outside and underground
gray water is not permitted for use on above ground veggies or root crops:: When ground is saturated, graywater must be diverted to site’s sewer disposal
simply switch your system off during the winter rainy season

INTERESTED IN HAVING A GRAY WATER SYSTEM AT YOUR HOUSE? FOLLOW THESE BASIC STEPS*:

1) Educate yourself on the design, installation, and maintenance requirements for a graywater system
2) Design your system or hire a licensed designer/contractor to design your system
3) If required, submit appropriate permit(s) and plan(s) to the local enforcement agency (see contact details listed below)
4) Install your system, obtain required inspection(s), and final permit
5) Maintain your system

*excerpted from Sonoma County's gray water systems brochure



For more information about gray water and Sonoma County, visit the Sonoma County Water Agency's web site at www.scwa.ca.gov/graywater

For more information about installing a gray water system at your home or business:
Unincorporated areas of Sonoma County: Visit PRMD on the web
City of Sonoma: Call 707-938-3681
City of Petaluma: Call 707-778-4301

Interested in reading more about gray water systems in the Bay Area?
See: Gray water systems growing in popularity, ingenuity and ease of installation, in the San Jose Mercury News

photos: Vianney Soto on flickr.com