- Author: Janet Hartin
- Author: Ben Faber
The use of graywater to irrigate landscape plants is increasing throughout the United States, particularly in California and other arid states. In the United States, "graywater" often refers to wastewater that originates from residential clothes washer, bathtubs, showers and sinks. It excludes wastewater generated from kitchen sinks, dishwashers and toilets (black water).
As of August 2009, a permit is no longer required for the installation of the following single-family or two-family residential graywater irrigation systems, if other conditions are met (California Department of Housing and Community Development): a) a simple clothes washing graywater system as long as it does not require cutting of the existing plumbing piping; and b) a single-fixture system that collects graywater from one plumbing fixture.
All other systems require a construction permit prior to creation, retrofitting, construction and installation as stated in the actual code. The full text of these standards can be viewed at the California Department of Housing and Community Development (HCD) Division of Codes and Standards website. Because these regulations may change at any time, always check with HCD and local enforcement agencies before developing plans for or installing a graywater system. Cities and counties can impose stricter guidelines than the state, so homeowners interested in installing a system should contact their local jurisdiction for specific regulations concerning graywater handling and use.
Laundry-to-landscape graywater systems are relatively simple to install and are inexpensive. The hose exiting the clothes washing machine is attached to a valve that separates graywater from water destined for the sewer. The graywater is diverted through a one-inch main irrigation line with a half-inch tubing outlets that are placed throughout the landscape, terminating in a valve box set called a "mulch basin." The basin surrounds plants being watered.
Benefits and Risks
Using graywater to irrigate landscape plants can conserve water and electricity and reduce water bills by recycling water otherwise destined for a wastewater treatment plant. Since an estimated 30 to 50 percent of home water use produces graywater, significant savings can be realized. A typical household (2.6 people) produces an average of 90 gallons of graywater each day. While most systems will not supply enough water to irrigate an entire traditionally landscaped yard, most can supply 1/2 to 3/4 of the water required by a drip-irrigated, water-efficient landscape with limited or no turf.
The potential risks should be carefully evaluated before deciding to install a graywater recycling system. Graywater varies substantially in quality and potential risks from site to site. Many household cleaning products contain dyes, bleach, chlorine, sodium, boron and phosphate, which can pose significant human and environmental health concerns and injure or kill plants at high dosages over a short period or smaller dosages over a long period.
Impact of Graywater on Human Health
Because of recent changes regarding graywater reuse under California and other state statutes, research pertaining to long-term impacts and risks of graywater reuse on human health, plant health, soil chemistry and ground and surface water quality is very limited.
Research examining the microbial constituency of graywater indicates that direct contact with graywater can pose a health risk to humans. Pathogens can enter graywater through food sources in the kitchen (which is why graywater generated from kitchen sinks and dishwashers is not recommended). Because pathogens can also enter graywater through fecal matter, avoid water contaminated by dirty diapers.
Graywater should not be applied directly to edible plants or root crops. To be safe, it should be applied only to nonedible ornamental plants. Avoid splashing graywater on neighboring edible plants. Also, graywater should not be applied using sprinkler systems, since droplets containing harmful microbes can become suspended in the air and breathed.
Impact of Graywater on Soil Chemistry and Water Quality
Limited research exists that addresses the fate of microorganisms found in graywater and the impacts on indigenous soil microorganisms, soil chemistry and water quality. Soil, rock and other materials that serve as filters can significantly diminish the threat of water pollution from graywater use.
Impact of Graywater on Plant Health
Because graywater is often rich in nutrients required for plant growth, ornamental plants may benefit from its use. However, numerous studies indicate that graywater may contain significant levels of sodium and other salts that are harmful to plants. In general, evergreens are more salt-sensitive than deciduous trees.
For more information on using graywater in urban landscapes, please contact Janet Hartin, environmental horticulture advisor, at firstname.lastname@example.org or (951) 313-2023. For information about UC Cooperative Extension's other programs, click here.
- Author: Dennis Pittenger
Each step can reduce water needs by as much as 10 percent. The impact on the landscape becomes more severe with each step; so stop with the step that results in enough water savings to meet your goal.
Step 1: Fix the hardware. Walk through the landscape while the irrigation system is running. Look for leaks at valves, heads and other parts of the irrigation system. Also, look for heads that apply water on pavement, are blocked by grass or other plant material, have poor spray or stream pattern, and are out of alignment.
Make the necessary adjustments or repairs. Be certain that spray or rotary heads are adjusted and spaced so that they apply water evenly from one head to another. If they do not, heads should be adjusted or added to get uniform water application. Also, be sure your irrigation controller is able to operate at least three separate programs with at least three start times. If it cannot, then replace it with one that has these features.
Step 2: Identify or create groupings of plants with similar water needs. This practice, known as hydrozoning, makes it easier to match irrigation schedules with plant water needs. During much of the year, most landscape plants need water less frequently and in less quantity than lawns. So, be sure each lawn area has its own valve or set of valves. Other areas of the landscape and garden, such as flowerbeds, groundcover areas, or shrub and tree plantings, should be irrigated by separate valves that can be set to water according to the unique needs of the plants.
Step 3: Assess and improve the irrigation schedules for each watering zone (hydrozone). Be sure the schedules for each valve apply the amount of water at the interval that meets the needs of plants without overwatering. Note how often and how long the irrigation system runs in order to keep the lawn and other plants up to standard. Compare these to the following general schedules and adjust yours down, if needed. In most non-desert locations, established lawns during the summer need irrigation no more than three or four days per week, with at least three watering cycles each irrigation day.
To apply enough water and avoid runoff, each cycle needs to run about 5 to 25 minutes, depending on the heads being use (rotary or fixed spray) and the amount of slope in the planting. Observe how many minutes it takes for runoff or puddling to begin. Then, take one minute off. This should be the maximum time at which you set one cycle. Cycles should be timed so that there is a break of several minutes to an hour between starts for each valve.
Established trees, shrubs and groundcovers usually need less water. Their irrigation should be less frequent (usually no more often than every 4 to 10 days in the summer). But enough water needs to be applied on a watering day to wet the soil about a foot deep. Again, schedule multiple cycles or use drip irrigation to do this without runoff.
Step 4: Reduce the amount of water applied to less than optimum. This practice is sometimes called deficit irrigating. With lawns and other frequently watered plants, reduce the runtime minutes by about 10 percent. For trees, shrubs and groundcovers, it is best to keep the runtime minutes the same and slightly extend the days between irrigation.
Lawns may develop some brown spots, and other plants may develop signs of drought stress.
Step 5: As a last resort, reduce the planted area being irrigated. First, consider reducing turfgrass areas or discontinue irrigating turf areas, as these are replanted more easily than groundcovers, shrubs or trees.
This step is the most dramatic and can yield some substantial water savings if large areas are stripped of plants or go unirrigated. Taking this action can also have significant negative side effects, such as increased heat load and dust in the area because the plants are no longer there to supply evaporative cooling, humidification and wind modification.
- Author: Keith Nathaniel
- Author: Dohee Kim
Last summer, I was reminded of why I get so much personal and professional satisfaction from being part of UC Cooperative Extension.
I was having a discussion with a group of 4-H youth, preparing them for summer camp as staff members. I was talking about their important role to serve as mentors and provide a memorable camp experience to more than 100 youth. It was at that moment when I realized that our program must have been important and meaningful to them because they have volunteered for a week to give that same experience to a new group of kids. For them, 4-H meant something, and they wanted to share it with others. That was a powerful realization.
Like the volunteers, I wanted to share what I experienced as a youth growing up in local youth programs in Compton. Nearly every day after school, I was fortunate to play, learn and grow in an after-school environment that nurtured my interests and skills in a safe place. The program staff were committed to providing this experience to all their youth participants. Field trips and overnight camping trips to Catalina Island as well as year-round sports activities helped to keep me safe and away from unhealthy, risky activities.
I also realized how important non-parental adults can be to young people. They help broaden the context of life and guide youth through experiences and opportunities that lead to a thriving adulthood.
So, I understand why these 4-H youth gave up part of their summer to be volunteer mentors. I, too, felt that need to share my positive youth experience with others. It is a wonderful thing to want to share.
- Author: Yvonne Savio
Wreaths, garlands, valance hangings and table decorations, graced with velvet ribbons and fruits and leaves of the season, are easy-to-make glories during the holiday season.
In ancient Rome, circular wreaths were symbols of victory and celebration. In 16th century Germany, fir or spruce wreaths were laid flat on a table with a candle lit on the first Sunday of Advent. Today, the wreath symbolizes continuity and tradition.
Evergreen boughs brought indoors by Druids were honored as sacred plants that didn't die, allowing the house to survive the winter. Primitive tribes in Europe hung evergreens above their doors during the winter solstice to offer woodland spirits shelter. They hoped that this would bring good fortune and health. Today's garlands continue to brighten our door and window sills, mantels and tables.
Your creation can be as simple as a bunch of your favorite herb branches tied with a ribbon, or as complex as a large and intricate wreath embellished with many sentimental items from a person's lifetime. It can be fancy or plain and worked on for weeks or completed on the spur of the moment. It all depends on what you want and what materials you have collected.
Materials can encompass anything you have access to, such as grapevine trimmings off the back fence and herb sprigs from the kitchen garden to pine cones from an excursion in the foothills. A great way to find unexpected goodies is to wander the aisles in a craft store, trying different combinations of textures and colors and seeing what strikes your fancy. Matching ribbons and other bits and pieces to friends' personalities is always great fun.
Looking at "ordinary" items in a new way can also reveal many possibilities. Green and red bell peppers add holiday cheer to a wreath on the front door. An oddly curled Armenian cucumber or long-necked squash becomes decoration in a table arrangement. A tree ornament becomes special when it's the only one on a wreath hung on child's door. Anything and everything becomes fair game for decorating. It's all up to your cleverness and sense of humor.
Materials to consider for the wreath or garland base
- A whole sunflower head with the central stem portion removed, forming a "donut"
- Dried sphagnum moss (the long stringy kind, not milled)
- Eucalyptus foliage
- Evergreen clippings (pine, spruce, holly, redwood, cedar, osmanthus and juniper)
- Forsythia branches (young)
- Herb foliage (bay laurel, coriander, sage, marjoram, oregano, rosemary, basil, lavender and pennyroyal)
- Honeysuckle trimmings
- Magnolia leaves
- Olive branches (young)
- Styrofoam flat shapes or balls
- Willow branches (young, peeled to reveal blond-colored wood)
- Wisteria trimmings
Materials to consider for decorations
- Candy canes
- Chili peppers
- Cookies (cutouts and gingerbread men)
- Dried ferns and other greens
- Dried flowers
- Dried fruits
- Dried Indian corn ears with husks partially removed to reveal colored kernels
- Dried rosebuds splashed with rose oil
- Dried safflower pods
- Eucalyptus pods
- Fabrics in rich colors, patterns and textures
- Fall-colored leaves
- Florescent glow strips and stickers
- Fresh flowers
- Fresh fruits
- Garlic heads
- Herb blossoms and berries
- Magnolia seed cones
- Miniature tree lights
- Nuts (walnuts, almonds, filberts, brazils and chestnuts)
- Onion bulbs
- Oranges stuck with whole cloves
- Popcorn on a string
- Pyracantha clippings of berries and leaves
- Ribbon candy
- Seed pods
- Shocks of wheat or sorghum
- Silk flowers
- Small statuary
- Your child's artwork
- Author: Leigh Johnson
- Author: Dohee Kim
Aquatic invasive species cause significant economic and ecological problems. Quagga and zebra mussels clog water supply systems and deplete plankton; their sharp shells endanger people who work, boat or fish in lakes. Tiny New Zealand mudsnails, which are poor food for fish, displace native snails. Invasive bullfrogs and clawed frogs voraciously consume native species and carry a disease that has decimated native frog populations. Dense mats of invasive waterweeds, such as hydrilla, spongeplant and water hyacinth, slow water flow in streams and irrigation channels, block boats, and kill native species by blocking out sunlight and causing oxygen levels to fall.
However, much of the damage can be reduced if people who work in aquatic habitats are trained. They can help lower the risks of spreading invasive species to new areas and serve as eyes and ears for resource agencies with a mission to manage and control these pests.
What has ANR Done?
In spring 2013, UCCE advisors in Southern California conducted six workshops for 181 staff members of local public works, parks, watersheds and flood control agencies as well as for staff members of a UC Research and Extension Center. The participants learned how to recognize 25 aquatic invasive species, decontaminate their field gear, plan their work to reduce risks of spreading these pests, and report sightings to resource agencies. Forty-nine percent of the participants were minorities and 29 percent were women. Through hands-on exercises, they practiced identifying species, detecting them in mud, inspecting boats and decontaminating boots. The advisors distributed decks of laminated reference cards (with photographs and information), which they created, at workshops. They also wrote blog articles to extend the workshop information widely.
The workshops were supported in part by the USDA Renewable Resources Extension Act and the counties of San Diego, Orange, Los Angeles and Ventura.
The participants significantly increased their ability to identify aquatic invasive species and their environmental impacts, their knowledge of how to report sightings, and their skills on how to decontaminate their gear and avoid spreading these pests. According to survey results, 80 to 90 percent of participants reported learning this information for the first time at one of the workshops. Within the first few following months, agencies reported having made changes. Two agencies implemented new or improved their existing decontamination protocols for field gear and planned their work accordingly to prevent the spread of aquatic pests. Two agencies educated the public on how to prevent the spread of pests by posting signs and talking to visitors at lakes. Five aquatic pest sightings were reported to field supervisors and a New Zealand mudsnail infestation was reported to three natural resources agencies. Altogether, these actions will help to prevent the spread of pests in areas where the workshops were conducted--all 2.5 million acres. More than 14,000 additional people learned about aquatic invasive pests from the advisors' blog articles that were based on their workshops.
"We used the workshop information to modify a permit to prevent a fire-fighting, water-dropping demonstration from spreading quagga mussels from an infested lake to an uninfested stream," said Cathy Nowak, sustainability planner with the Orange County Parks Department.