Mariposa Gardening and Design Blog
Graywater!
For the past few years, Northern California has been going through a natural dry cycle. With our community’s current level of water consumption, these dry cycles spell drought. Mariposa Gardening & Design’s Living Fountain is one solution to the drought we are experiencing. With it and other graywater systems, a household would be able to re-use more than half of its residential water consumption to irrigate gardens.(1) In additon to saving households money, smart re-use of water has positive ecological benefits. By using graywater in the landscape, water is diverted from overburdening the municipal system and instead effectively treated on site with plant roots and soil, rather than with chemicals.* Graywater can also be used to recharge the sub-surface groundwater which gets taxed during dry years. The Living Fountain is a graywater system that not only allows people concerned about water conservation to have beautiful lush gardens that attract birds and butterflies, but the fountain itself provides habitat for water loving insects like dragonflies. (see Living Fountain Update)
So What Is Graywater?
Graywater is non-industrial wastewater generated from domestic processes such as dish washing, laundry and bathing. “graywater” is so called because it is neither pristine potable water, nor contaminated “blackwater”. (Toilet-flush water is considered blackwater, and wastewater from the kitchen sink is also regarded as blackwater due to contamination by food particles, grease, and household cleaning chemicals.) After being filtered through a variety of natural materials such as sand, gravel, and the fine hairs of wetland plant root mats, it can safely be used to irrigate landscapes and gardens.
Re-using Graywater Helps Out During Dry Times.
This past year, the East Bay Municipal Utility District (EBMUD), implemented a drought management program that increased volume charges, added a small surcharge on use that exceeds the restricted level, and asked consumers to reduce their irrigation water consumption by 30%.(2) EBMUD is rewarding customers who use less than 100 gallons per day by exempting them from the price increase.
Graywater accounts for 50-80% of residential water consumption. This means that a large portion of the water that flows down the drain and away to the wastewater treatment plant is water that is not seriously contaminated, and is in prime condition to be re-used. The most practical application for re-used graywater is in the landscape. The average American creates approximately 40 gallons of graywater per day. A family of four can produce about 1,120 gallons per week which could be used to irrigate 2,240 square feet of garden.(3) Mariposa Gardening & Design team can help you design and install a graywater system that re-uses your uncontaminated household waste water to irrigate your own backyard oasis. Using gravity, natural filtration methods, and recycled materials, our team creates lasting elegant designs bringing vitality and ecological harmony to your garden.
What About Sanitation?
As the need for water conservation increases, currently acceptable practices regarding on-site treatment and distribution of graywater are under examination. Since 1995, California residential graywater use has been governed by the “Graywater Guide”, which allows only for subsurface drip irrigation systems, or other subsurface distribution. These guidelines, while well intentioned, do not take into consideration any of the other effective and potentially beautiful systems for graywater use in the landscape. However, on July 2, 2008 the California State Senate passed SB 1258, which instructs “the Department of Housing and Community Development to develop a more wide-ranging set of standards for graywater systems for both indoor and outdoor uses.” (4)
For us here at Mariposa Gardening & Design, the prospect of new codes allowing for broader application of graywater in the landscape is inspiring. We intend to continue working with our local permitting agencies to develop codes that make sense in our drought prone climate.
For more information on SB 1258, please look at The California Water Policy Center website: http://www.oasisdesign.net/Graywater/law/#california
*An update describing different systems of ecological water treatment to come.
(1) http://www.Graywater.net/
(2) http://www.ebmud.com/drought/restrictions.html
(3) http://www.drinktap.org/consumerdnn/Default.aspx?tabid=85
(4)http://www.wrb.state.ri.us/education/wtroutdoor_factsheet.pdf