Greywater, Green Landscape: How to Install Simple Water-Saving Irrigation Systems in Your Yard
201
Greywater, Green Landscape: How to Install Simple Water-Saving Irrigation Systems in Your Yard
201eBook
Available on Compatible NOOK devices, the free NOOK App and in My Digital Library.
Related collections and offers
Overview
Product Details
| ISBN-13: | 9781612128405 |
|---|---|
| Publisher: | Storey Publishing, LLC |
| Publication date: | 04/08/2025 |
| Sold by: | Barnes & Noble |
| Format: | eBook |
| Pages: | 201 |
| File size: | 28 MB |
| Note: | This product may take a few minutes to download. |
About the Author
Laura Allen is the author of The Water-Wise Home and cofounder of Greywater Action, a collaborative of educators who teach residents and tradespeople about affordable and simple household water systems that dramatically reduce water use and foster sustainable cultures of water. She leads classes and workshops, including the first training program for professional greywater installers, and participates in writing state government greywater and composting toilet codes. She lives in Eugene, Oregon.
Read an Excerpt
CHAPTER 1
Greywater Systems 101
The first step to design and install a greywater system is to understand your options.
These include the different types of systems, their general costs, their strengths and limitations, their benefits, and their health and safety considerations. This chapter provides the foundation you'll need for the details and calculations in the upcoming chapters.
IN THIS CHAPTER:
* Water Saving Potential and Costs
* Pros and Cons of Using Greywater
* Types of Greywater Systems
* Health and Safety Considerations
* Greywater in Freezing Climates
What Is Greywater?
Greywater is gently used water from sinks, showers, baths, and washing machines; it is not wastewater from toilets or laundry loads containing poopy diapers. Plants don't need clean drinking water like we do! Using greywater for irrigation conserves water and reduces the energy, chemicals, and costs involved in treating water to potable quality.
Reusing water that we already have is a simple and commonsense idea. Just use "plant friendly" soaps (those low in salts, and free of boron and bleach), and you have a good source of irrigation water that's already paid for.
Greywater systems save water and more. They can extend the life of a septic system, save time spent on watering, act as "drought insurance" (a source of irrigation during times of extreme water scarcity), and encourage the use of more environmentally friendly products. They also use less energy and fewer chemicals than other forms of wastewater treatment.
Water Savings from Greywater
You can expect to save between 10 and 20 gallons per person per day (or more) from a greywater system, though this number can fluctuate greatly. Studies estimate savings of between 16 and 40 percent of total household use. How much you actually save depends upon how much you currently irrigate, whether you use greywater on existing plants or you plant new ones, and how many greywater sources you can access. One study in Central California found an average household savings of 15,000 gallons per year after the greywater system was installed (see Resourcesfor more information). For tips on how to maximize water savings with your greywater system, see Maximize Your Water Savings.
Cost of Greywater Systems
Materials for simple greywater systems typically cost a few hundred dollars. If you're handy, you can install a system yourself in a day or two. Professional installations range from $700 to many thousands of dollars, depending on the type of system and your site. We'll discuss more details about specific system costs in chapter 6.
A WATER-EFFICIENT HOME AND LANDSCAPE
Before you start planning and constructing your greywater system, be sure to make your home and landscape as water-efficient as possible. Leaks waste an average of 14 percent of total home water use. Toilet and irrigation system leaks are often hidden and go undetected. A simple "mini makeover," such as switching out water-guzzling fixtures and appliances for efficient models, can lower total household water use by up to 35 percent.
Equally important is making your landscape water-smart. Plants that aren't able to be irrigated with grey-water (or rainwater) should be those that are adapted to your local climate and are able to thrive without potable irrigation.
This book guides you through the design and installation of several types of greywater systems, but to maximize the full range of your water resources you'll also want to incorporate rainwater harvesting into your overall landscape design. See Resources for more information.
Types of Greywater Systems
There are many types of greywater systems, ranging from simply collecting water in buckets to fully automated irrigation systems. I'll group them according to their relative level of complexity and briefly explain how they work.
"LOW-TECH" SYSTEMS for irrigation are the lowest in cost, simplest to install, and easiest to obtain permits for. Common types include laundry-to-landscape (L2L) and branched drain systems.
"MEDIUM-TECH" SYSTEMS for irrigation incorporate a tank and pump to send greywater uphill or to pressurize it for drip irrigation.
"HIGH-TECH" SYSTEMS are used for automated drip irrigation or toilet flushing in high-end residences and larger-scale commercial or multifamily buildings.
Hooray for the Washing Machine!
Washing machine water is typically the easiest source to reuse; you can direct greywater from the drain hose of the machine without cutting into the house's plumbing. A washing machine has an internal pump that automatically pumps out the water and can be used to direct greywater to the plants.
No-Fuss Gravity Systems from Showers and Baths
Showers and baths are excellent sources of greywater, though accessing the drainpipes may be challenging, depending on their location. A diverter valve placed in the drain line of the shower allows greywater to be diverted to the landscape. Gravity distribution systems are usually cheaper and require less maintenance than pumped systems, and distribute greywater through rigid drainage pipe. Greywater flow is divided into multiple irrigation lines to irrigate trees, bushes, vines, or larger perennials via mulch basins (see Mulch Basins).
PROS OF GREYWATER SYSTEMS
* Greywater is produced every day, all year long, and is a reliable source of irrigation.
* Simple systems recycle tens of thousands of gallons a year for a relatively low cost.
* Systems take up little space; often, all the pipes are buried and invisible.
* It's easy to irrigate fruit trees, shrubs, and large annuals and perennials.
* It's an automatic system, saving time and ensuring plants get watered.
* It reduces wastewater going to the sewer or septic system.
CONS OF GREYWATER SYSTEMS
* Accessing greywater may be challenging, depending on how your house and landscape are designed.
* Greywater reuse is not yet legal in some states.
* Requires use of "plant-friendly" products in the house.
* Small plants, or plants spread out over a large area, are more difficult to irrigate with the simplest systems, though pumped and filtered systems will work.
Pumped Systems: Filtered and Unfiltered Pumped systems push greywater uphill or across long distances. Greywater is diverted into a surge tank, from which it's pumped to the landscape. Adding a filter allows greywater to be distributed through smaller tubing, increasing the potential irrigation area but also increasing the cost and maintenance of the system.
Greywater Pioneer
Art Ludwig
He has studied and worked in 22 countries, authored the books Create an Oasis with Greywater (an excellent resource containing his decades of greywater experience) and Builder's Greywater Guide, and produced the "Laundry to Landscape" instructional video. He created the first plant and soil "biocompatible" laundry detergent, designed to break down into plant nutrients (see Resources). Art's most popular greywater inventions include the laundry-to-landscape and branched drain greywater systems. His policy work has greatly improved regulations in California, New Mexico, Arizona, and elsewhere.
What advice do you have for people wanting to install a greywater system?
Choose the simplest possible approach and implement it as well as possible.
What's your all-time favorite greywater system?
My favorite greywater system is my first branched drain system. I thought it would fail in a day, but it didn't. If fact, I couldn't get it to fail no matter what I did. Even after removing the screen in my kitchen sink and pushing compost scraps down the drain, the sink trap clogged daily, but everything that made it past the trap flowed out to the mulch basin via a free flow outlet, with no odors, no clogging, and no problems.
GREYWATER OR GRAYWATER?
People often wonder why greywater is spelled two different ways. All around the world greywater is spelled with an "e," except by a few groups in the U.S., mostly regulators who write state codes (though some states, like Washington, use the "e" spelling). I like the "e" spelling to intentionally connect greywater to the global movement around water.
Health and Safety Considerations
A properly designed greywater system is safe for you and your family as well as the environment. As you design your system, keep the following considerations in mind:
* Greywater is not safe to drink or ingest.
* Greywater can harm aquatic ecosystems.
* Avoid direct contact with greywater; your system should not create a puddle, pond, or any standing water, which creates a hazard to unsuspecting children and a place for mosquitoes to breed.
* When watering food plants, don't let greywater contact edible portions of the food (to avoid direct ingestion). Don't irrigate root vegetables. Use subsurface irrigation for growing edibles near the ground.
* Never use greywater in sprinklers where the spray could be breathed in.
Polluting Aquatic Ecosystems
The nutrients found in greywater are good for your garden but harmful to lakes, streams, and oceans. In the garden, the nutrients are fertilizer, sent to your plants each time you do laundry. If, instead of soaking into the soil, greywater runs into the storm drain and out to a river or bay, the nutrients pollute the water, feeding algae and robbing oxygen from aquatic organisms. This is similar to how the gigantic "dead zones" are created in our bays and oceans, usually by fertilizer runoff and sewer overflows. Don't let your greywater contribute!
Hazardous chemicals should never be used with a greywater system (or anywhere); they will contaminate your yard. When sent to the sewer plant they usually aren't removed either, and will end up in a river, lake, or ocean.
IS GREYWATER A HAZARD TO YOUR HEALTH?
Some people hold the mistaken belief that greywater is hazardous, on par with sewage. There are many studies on the quality of greywater with respect to public health. Here are some key points:
* Greywater is not safe to ingest. The quality is lower than drinking water quality. So don't drink greywater!
* Greywater-irrigated soil is not safe to ingest, nor is soil irrigated with tap water. The City of Los Angeles conducted a study comparing greywater-irrigated soil and non-greywater-irrigated soil. Both were found to be unhealthy to ingest.
* Many studies have found fecal indicator bacteria present, demonstrating the potential for greywater to contain fecally transmitted pathogens. A problem with using indicator bacteria, like fecal coliforms, is that the bacteria are present in all mammals' feces and can multiply on their own, resulting in inaccurate estimates of fecal matter in greywater. Other studies tested greywater for a cholesterol found only in the human gut, unable to grow on its own, and found the levels of feces reported in the other studies using indicator bacteria were 100 to 1,000 times too high. Does this matter? Some people still believe greywater isn't much cleaner than sewage and don't know that the methods used to test greywater were grossly inaccurate.
* Few studies have found actual pathogens in greywater. Testing for specific pathogens is expensive, and pathogens are found only if someone in the home has the illness and germs get into the water. Some studies that tested for pathogens didn't find any, while others found common pathogens like Cryptosporidium spp. and Giardia spp., which are also found in most surface waters in the U.S. When people are sick they infect others by living together, directly touching, and sharing dishes; the risk of infection through a greywater system is extremely low.
* There are no documented cases of illness resulting from greywater, while there are over three million documented cases of illness each year (just in the U.S.) from recreational contact with water contaminated by legal sewage treatment plants that overflow.
Is greywater hazardous to your health? No. Most likely greywater use improves public health by reducing waterborne illness since the only people potentially exposed already live together and greywater is kept out of sewer systems that often fail.
Greywater in Freezing Climates
Live somewhere chilly? Maintaining a greywater system in freezing conditions requires additional planning and precautions:
* Gravity systems should drain completely. Standing water in the pipes could freeze and create a blockage, or potentially burst the pipe. Meticulously maintain proper slope throughout the entire system to ensure complete drainage.
* Do not allow any standing water in lines from pumped systems. Ensure greywater will drain out or drain back into the tank.
* In a pumped or L2L system: If it's logistically difficult to prevent standing water in the line, create an automatic bypass at the beginning of the system. If the main line freezes, water will be forced out the bypass; for example, a tee fitting with a tube running high enough up so greywater doesn't exit unless the line is blocked (if the tube is too short, greywater will come out like a fountain).
* Greenhouses irrigated by greywater (seeGreywater for Greenhouses) can produce food and greenery all year long.
* Shut off the system (and drain down any places with standing water) until irrigation is needed. Install a drain-down valve at the low point of the system to empty the pipes for winter. Use a tee with a ball valve at the lowest point. Close the valve when using the system and open it to drain the line. Note: Shutting off the system may be unnecessary, even with freezing, snowy weather. The warmth in greywater can keep lines open and the ground biologically active (see Cold-Climate Greywater: Evergreen Lodge below).
* Consider a toilet-flushing system if there is no irrigation need. (See Using Greywater Indoors: Toilet Flushing.)
Cold-Climate Greywater
Evergreen Lodge
Over the past few years, Regina and her crew installed dozens of systems at the lodge, both simple gravity-fed branched drain systems (in 55 guest cabins) and large automated systems from the commercial laundry and staff dorms.
"The system is a big win for the lodge," reflects owner Brian Anderluh. "We were able to take greywater out of our septic system and use it instead for our landscape beautification project, without requiring any more fresh water from our well."
Regina, an ecologist turned landscaper, notes, "Plant productivity at Evergreen Lodge has increased threefold since we installed these systems, and soil biota is on the rise."
Even though the lodge gets an average of 30 inches of snow annually, the systems operate problem-free all winter long. The team carefully designed each system so that no standing water remains in the lines to freeze, and the soil remains biologically active from the warmth of greywater.
"Branched drain systems far exceed the pumped systems; however, controller-based valved systems have been reliable for nearly six years with high demands due to drought conditions," notes Regina.
One system repurposes an existing irrigation system. They removed the emitters and sent filtered greywater through the ¼-inch tubing to landscaping in the main courtyard.
Unexpected Benefits
Regina has been monitoring the systems since 2009. "We've seen some really exciting results. The soil is being decompacted by the mulch basin systems. When we first began testing, the soil was so hard we could barely insert the compaction meter rod in an inch; now we are reaching over 62 inches down. Even though many different people use these cabin shower systems and put their different products into the greywater, we have not seen any problems with salt buildup in the soil. And the biggest surprise benefit is the greywater-irrigated plants appear to be fire-resistant!"
In 2013, California's third-largest wildfire (the Rim Fire) burned over 250,000 acres in the Sierra Nevada mountains, and burned within feet of Evergreen Lodge. Regina reflects, "The area was evacuated from August until October, with no irrigation or greywater production. When we finally got in I expected all the plants to have died. Out of 1,500 plants, we lost 90% of the plants irrigated with potable water, but less than 5% of greywater-irrigated plants had died." This is especially significant since two-thirds of all the irrigated plants at the lodge were on greywater.
"The systems at Evergreen Lodge have been so successful, the owners of a new lodge (Rush Creek) being built nearby decided to use 95% of the greywater generated for irrigation. In fact, this new lodge will not use any potable water for irrigation."
(Continues…)
Excerpted from "Greywater, Green Landscape"
by .
Copyright © 2017 Laura Allen.
Excerpted by permission of Storey Publishing.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.
Table of Contents
Part 1: Planning Your Home Greywater System1 Greywater Systems 101
What Is Greywater?
Types of Greywater Systems
Health and Safety Considerations
Greywater in Freezing Climates
2 Greywater Sources and Plumbing
Identify Your Greywater Sources
Your Home's Drain, Waste, and Vent System
Undesirable Greywater Sources
Summary of Greywater Sources
3 Estimate Your Greywater Flows
Code Estimates vs. Personal Calculations
Calculating Weekly Greywater Flows
Finding the Flow Rates of Different Fixtures
4 Soils and Mulch Basins
Soil Structure and Type
Identify Your Soil Type with a Soil Ribbon Test
Determine How Water Flows through Your Soil with an Infiltration Test
Mulch Basins
Protect Groundwater and Drinking Water Wells
5 Plants and Irrigation
Choosing Plants for Greywater Irrigation
How Much Water Do My Plants Want?
Plant-Friendly Soaps
6 Choosing a Greywater System
System Design Considerations
When Greywater Is Not a Great Idea
Using Greywater Indoors: Toilet Flushing
Choosing a Greywater Irrigation System
Greywater Systems at a Glance
When to Turn Off the System
7 Codes and Regulations
A Brief History of Greywater Plumbing Codes
Greywater Codes: Performance and Prescriptive
National Codes and Standards
Part 2: Building Your Home Greywater System
8 Install a Laundry-to-Landscape (L2L) System
Design Considerations
Installing an L2L Irrigation System
Irrigation Options
9 Install a Branched Drain Gravity-Flow System
Design Considerations
Installing a Branched Drain System
How to Wire an Actuator
10 Pumped and Manufactured Greywater Systems
Design Considerations
Building a Pumped System
Manufactured Greywater Systems
11 Other Types of Greywater Systems
Outdoor Fixtures
Whole-House Greywater Systems
Subsoil Infiltration Systems
Greywater for Greenhouses
Constructed Wetlands
Sand Filter to Drip Irrigation
Reusing Septic Tank Effluent for Irrigation
Appendix
Plumbing Basics for Greywater Installation
Parts Primer
Basic Installation Techniques
Resources
Acknowledgments
Index