Home-to-Landscape Greywater Irrigation, with John Whittlesey

I am going on several winter weeks without rain (or snow) on my garden. I am enjoying the sun, but I am very aware of the lack of needed water as well. If you are a gardener (or living creature of any variety really), water is a fairly constant topic of interest to you – and to your garden. It is one of the small-handful of things that neither we, nor our gardens can live without and as a result its sources, supply and usage are of paramount importance. Photo: A John Whittlesey garden design featuring low-water plants – and what, in winter, I dream of my garden being come summer. Photo by John Whittlesey, 2010.

Our Northern California Mediterranean climate is generally characterized by mild, wet winters, and hot, dry summers. As such, water for us is often a matter of feast or famine – general plenty in the winter followed by sometimes 6 or more months without one drop falling from the sky. But even in our “wet” winters we can experience droughty weeks.

Perhaps it is this recent warm dry stretch, or because this early to mid-winter period is often one of planning for the future of our gardens, but my thoughts have turned to greywater.

Also known as grey water, graywater, or gray water, but most often referred to as greywater, this is the water ‘waste’ that our households pour forth into sewer lines and septic tanks from the washing machines, sinks, bathtubs and showers throughout our homes. It is very different from what is known as ‘blackwater,’ which includes true sewage from toilets, or water waste quite likely to carry noxious pathogens from the heavily and variously used kitchen sink, and is not re-used without treatment. Greywater on the other hand has amazing potential “for watering our home landscapes throughout the year,” John Whittlesey tells me. Well-known plantsman, John is the owner of Canyon Creek Nursery and Design, specializing in the design and installation of water wise gardens and greywater systems, and he talks to us about the landscape irrigation potential for greywater in this week’s In a North State Garden. Photo: Most home sinks, other than the kitchen sink, are good candidates for incorporating into a greywater re-use system. Home sinks, showers and tubs, however, often require permitting and inspection due to needing a more sophisticated branched-drain design.

Greywater as a concept is elegant in its simplicity.

Greywater reuse ‘systems’ are relatively easy and inexpensive embodiments of the reduce, reuse, recycle ideal, wherein any given amount of water is used more than once and for more than one purpose. You wash your clothes, and subsequently use the same water to quench your rose border. This same water then percolates through the soil, stimulating microbial activity along the way to also recharging the groundwater … it’s an effective cycle in nature for good reason. Photo: The clearly marked valve allowing a homeowner to send laundry water either to the greywater irrigation system or to the septic system in the event harsh cleaners (bleach), human (baby diapers) or petrochemical waste (oil spills) might be in the wastewater.

In almost all that he does as a designer, a long-time nurseryman, native plant educator and enthusiastic home gardener himself, John advocates for the thoughtful use of any resource. In the fall of 2010, he wrote regarding water conservation in the garden: “If a gardener is reassessing their garden in terms of water use, with an intent to reduce irrigation, they need to take a close look at the plants in their garden: if there are high water need plants, is the gardener really attached to them? If so, are the high water need plants consolidated? Can the gardener keep the water-loving plants in one place, say on one watering zone near the house or around a patio, and use more drought tolerant plants on the periphery?” Photo: Drought tolerant plant selections at Canyon Creek Nursery & Design, by appointment only.

“And of course,” he continued, “gardeners should take a look at the lawn in their landscape, does it serve a purpose, such as playing on – or entertaining, or is it there as a default. As Michael Pollan wrote, ‘For as soon as an American decides to rip out a lawn, he or she becomes, perforce, a gardener, someone who must ask the gardener’s questions: What is right for this place? What do I want here?….. How can I make use of nature here without abusing it?”

Always encouraging other gardeners to avoid gardening habits or choices which are done by default rather than as a result of careful deliberation, in the early summer of 2010, John became certified as a Greywater Systems Installer through an intensive hands-on course offered by Greywater Action based in Petaluma, California. Photo: John Whittlesey.

How re-using greywater became illegal in the first place is a bit difficult to figure out, but seems to go hand in hand with the development of more and more caustic soaps, detergents and cleaners that pollute soil and groundwater. Through the course of the late 1980s and 1990s, many western states adopted regulation allowing for the careful re-use of greywater with an eye to ensuring such heavy chemicals, industrial waste, and/or human waste could be effectively prohibited from such re-use. As a result of a long and convoluted history, the re-use of greywater can have state and county regulations associated with it. However, John writes, “in 2009, California updated their greywater systems code to encourage water conservation by facilitating re-use of water, allowing for simple home-laundry-to-landscape greywater systems as well as more complex shower and bathroom sink systems, which require permits. This is a big step forward in allowing individuals to have more control over their water usage. Using greywater for irrigation not only helps conserve water; it reduces flows into resource intensive water treatment plants, and closes the energy cycle on home properties. Water and nutrients are kept on site to slowly filter into the soil.” Photo: The construction of a mulch basin allowing for the release of greywater two inches below the surrounding soil level, but above the filtering wood chips.

After working on his first few greywater system designs and installations, Whittlesey enthused: “Cheers to greywater running out under a rose bush or a lemon tree. How satisfying to hear a washing machine and know the water is being sent to the garden.

The most easily installed and least regulated system to begin with is probably a ‘simple’ laundry to landscape system, John says. With the help of his family, he installed such a system at their home, nestled in a scenic oak and grassland valley outside of Oroville. The Whittlesey’s home water comes from a gravity fed spring and so they are perhaps even more aware of water usage than those of us with the apparent ease and abundance of city water, although rising municipal water bills are certainly encouraging awareness as well. Photo: New pipe at the Whittlesey’s home taking laundry water out to irrigate the landscape. Such pipes are clearly labeled as non-potable water.

With a laundry-to-landscape system, the washing machine’s plumbing for draining the used water is reworked to include an outlet into the landscape, as well as the original outlet to the sewer/septic. “The key interior part in a laundry to landscape system is the 3-way valve to allow switching between landscape and sewer,” so that if you are washing something like baby diapers or you need to do a load with bleach, let’s say, you can and should send that water to the sewer. “One of the things you’ll need to pay attention to is what products you buy for washing your clothes to make sure they do not include sodium or salts, boron or chlorine bleach. Even some of the detergents labeled ‘all natural’ will have sodium in them, which you don’t want, so read your labels carefully.”

Water draining from the washing machine is then transported through pipes buried in trenches to where irrigation is desired. The Whittlesey’s laundry water is carried under a main pathway and then branched to provide water to multiple points along an established rose and tree border. “Mulch basins are the end of the line key component to any greywater system,” John explains. “By law the release is two inches below the surface, into a basin sized according to soil type and amount of water. The basin is filled with wood chips.” Photo: Students digging trenches for a branched drain system during Greywater Action’s installer’s certification training. Photo by John Whittlesey.

“There are several reasons for running greywater through mulch. The uppermost layer of soil, where there is air and organic material, has the highest concentration of bacteria, fungi and all manner of soil life which decompose things. This, in a way, is what is being created in a mulch basin. There is air and organic material, which creates a home for the rich biology to break down the particles (such as hair, lint, etc.) that flow from the laundry or shower. If you ran grey water directly onto or into soil, it would break down, only at a slower pace and the soil could get slimy and clogged. The mulch basins keep things filtering and moving.”

While much of your landscape will benefit from greywater irrigation, “you don’t use greywater on plants the edible part of which could come into direct contact with the greywater,” John points out. So the general rule is to not water your vegetable garden with greywater. But fruit trees, vines and plants such as tomatoes, peppers and eggplant, which bear their fruit above the soil, are fine candidates. Likewise, if you are watering low-water plants with your system, such as native or Mediterranean plants that do not want a lot of water in the summer time, you need to pay attention to not overwater with your system.

“With a greywater system much thought can and should go into the amount of water available and needed, where it ends up and how to calibrate it across the garden,” as well as across the lifetime of a garden’s plants – newly planted versus established plants, edibles versus ornamentals, dry-land plants versus moisture-loving plants. “There are limitations to greywater irrigation, and the whole picture needs to be looked at, amount of water gained for the landscape, cost and the impact on the landscape. The benefits and feasibility vary from garden to garden depending on amount of water used, soil type, and landscape area to be irrigated.”

Of course, even more elaborate systems are possible in order to make use of your showers, tubs, bathroom and laundry room sinks. When you consider that according to many sources “the average person uses fifty gallons of water per day on the following activities:· Toilet – 19 gallons per day· Bathing & hygiene – 15 gallons per day· Laundry – eight gallons per day· Kitchen – seven gallons per day· Housekeeping – one gallon per day,” the potential for possible reuse is quite staggering.

As one source said, “Awareness is the first step in conservation.” So now I am not only dreaming about what my garden looks like come summer, I am also dreaming of the happy sound of my family of four’s washing machine gurgling as it drains out and waters this garden.

If you have any questions about greywater systems or waterwise garden design and plant choices, John Whittlesey is happy to consult with do-it-yourselfers, as well as provide designs and install them. He can be reached by email johnccn@sunset.net or by phone 530 774-4955.

Lots of good information is out there about greywater. For a sense, peruse the Greywater Action website – you will be inspired. www.greywateraction.org.

Whittlesey will be speaking on Water Conservation in the Garden for the Chico Horticultural Society’s daytime meeting on Wednesday February 16th, 2011 at 10 am at Butte County’s Chico Library 1108 Sherman Avenue.

Whittlesey is also a featured speaker for the California Garden Clubs, Inc. 2011 Northern California Wildflower Weekend (http://www.norcalwildflowers.org/) April 1 -3 in Oroville.

In a North State garden and Jewellgarden.com are THREE YEARS OLD as of February 2011. Happy Anniversary! All purchases made from Jewellgarden.com’s shop page of beautiful, botanically inspired printed products directly support the production of this weekly gardening program. All remaining 2011 Calendars and holiday cards are now on Sale 50% off! Follow Jewellgarden.com/In a North State Garden on Facebook – become a fan today!

To submit plant/gardening-related events/classes to the Jewellgarden.com on-line Calendar of Regional Gardening Events, send the pertinent information to me at: Jennifer@jewellgarden.com
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In a North State Garden is a weekly Northstate Public Radio and web-based program celebrating the art, craft and science of home gardening in Northern California. It is made possible in part by the Gateway Science Museum – Exploring the Natural History of the North State and on the campus of CSU, Chico. In a North State Garden is conceived, written, photographed and hosted by Jennifer Jewell – all rights reserved jewellgarden.com. In a North State Garden airs on Northstate Public Radio Saturday mornings at 7:34 AM Pacific time and Sunday morning at 8:34 AM Pacific time. Podcasts of past shows are available here.

Jennifer Jewell

In a North State Garden is a bi-weekly North State Public Radio and web-based program celebrating the art, craft and science of home gardening in Northern California and made possible in part by the Gateway Science Museum - Exploring the Natural History of the North State and on the campus of CSU, Chico. In a North State Garden is conceived, written, photographed and hosted by Jennifer Jewell - all rights reserved jewellgarden.com. In a North State Garden airs on Northstate Public Radio Saturday morning at 7:34 AM Pacific time and Sunday morning at 8:34 AM Pacific time, two times a month.

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